HBASE-6836 Offline snapshots (Jesse Yates)

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/hbase-7290@1445782 13f79535-47bb-0310-9956-ffa450edef68

hbase-common/src/main/java/org/apache/hadoop/hbase/HConstants.java

@@ -741,10 +741,17 @@ public final class HConstants {
   /** Directory under /hbase where archived hfiles are stored */
   public static final String HFILE_ARCHIVE_DIRECTORY = ".archive";
 
+  /**
+   * Name of the directory to store snapshots all snapshots. See SnapshotDescriptionUtils for
+   * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
+   * uni-directional.
+   */
+  public static final String SNAPSHOT_DIR_NAME = ".snapshot";
+
   public static final List<String> HBASE_NON_USER_TABLE_DIRS = new ArrayList<String>(
       Arrays.asList(new String[] { HREGION_LOGDIR_NAME, HREGION_OLDLOGDIR_NAME, CORRUPT_DIR_NAME,
           toString(META_TABLE_NAME), toString(ROOT_TABLE_NAME), SPLIT_LOGDIR_NAME,
-          HBCK_SIDELINEDIR_NAME, HFILE_ARCHIVE_DIRECTORY }));
+          HBCK_SIDELINEDIR_NAME, HFILE_ARCHIVE_DIRECTORY, SNAPSHOT_DIR_NAME }));
   
   private HConstants() {
     // Can't be instantiated with this ctor.

hbase-protocol/src/main/java/org/apache/hadoop/hbase/protobuf/generated/HBaseProtos.java

@@ -11321,6 +11321,10 @@ public final class HBaseProtos {
     // optional .SnapshotDescription.Type type = 4 [default = TIMESTAMP];
     boolean hasType();
     org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Type getType();
+    
+    // optional int32 version = 5;
+    boolean hasVersion();
+    int getVersion();
   }
   public static final class SnapshotDescription extends
       com.google.protobuf.GeneratedMessage
@@ -11352,20 +11356,23 @@ public final class HBaseProtos {
     
     public enum Type
         implements com.google.protobuf.ProtocolMessageEnum {
-      TIMESTAMP(0, 0),
+      DISABLED(0, 0),
-      GLOBAL(1, 1),
+      TIMESTAMP(1, 1),
+      GLOBAL(2, 2),
       ;
       
-      public static final int TIMESTAMP_VALUE = 0;
+      public static final int DISABLED_VALUE = 0;
-      public static final int GLOBAL_VALUE = 1;
+      public static final int TIMESTAMP_VALUE = 1;
+      public static final int GLOBAL_VALUE = 2;
       
       
       public final int getNumber() { return value; }
       
       public static Type valueOf(int value) {
         switch (value) {
-          case 0: return TIMESTAMP;
+          case 0: return DISABLED;
-          case 1: return GLOBAL;
+          case 1: return TIMESTAMP;
+          case 2: return GLOBAL;
           default: return null;
         }
       }
@@ -11396,7 +11403,7 @@ public final class HBaseProtos {
       }
       
       private static final Type[] VALUES = {
-        TIMESTAMP, GLOBAL, 
+        DISABLED, TIMESTAMP, GLOBAL, 
       };
       
       public static Type valueOf(
@@ -11504,11 +11511,22 @@ public final class HBaseProtos {
       return type_;
     }
     
+    // optional int32 version = 5;
+    public static final int VERSION_FIELD_NUMBER = 5;
+    private int version_;
+    public boolean hasVersion() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    public int getVersion() {
+      return version_;
+    }
+    
     private void initFields() {
       name_ = "";
       table_ = "";
       creationTime_ = 0L;
       type_ = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Type.TIMESTAMP;
+      version_ = 0;
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
@@ -11538,6 +11556,9 @@ public final class HBaseProtos {
       if (((bitField0_ & 0x00000008) == 0x00000008)) {
         output.writeEnum(4, type_.getNumber());
       }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        output.writeInt32(5, version_);
+      }
       getUnknownFields().writeTo(output);
     }
     
@@ -11563,6 +11584,10 @@ public final class HBaseProtos {
         size += com.google.protobuf.CodedOutputStream
           .computeEnumSize(4, type_.getNumber());
       }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeInt32Size(5, version_);
+      }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
       return size;
@@ -11606,6 +11631,11 @@ public final class HBaseProtos {
         result = result &&
             (getType() == other.getType());
       }
+      result = result && (hasVersion() == other.hasVersion());
+      if (hasVersion()) {
+        result = result && (getVersion()
+            == other.getVersion());
+      }
       result = result &&
           getUnknownFields().equals(other.getUnknownFields());
       return result;
@@ -11631,6 +11661,10 @@ public final class HBaseProtos {
         hash = (37 * hash) + TYPE_FIELD_NUMBER;
         hash = (53 * hash) + hashEnum(getType());
       }
+      if (hasVersion()) {
+        hash = (37 * hash) + VERSION_FIELD_NUMBER;
+        hash = (53 * hash) + getVersion();
+      }
       hash = (29 * hash) + getUnknownFields().hashCode();
       return hash;
     }
@@ -11755,6 +11789,8 @@ public final class HBaseProtos {
         bitField0_ = (bitField0_ & ~0x00000004);
         type_ = org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Type.TIMESTAMP;
         bitField0_ = (bitField0_ & ~0x00000008);
+        version_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000010);
         return this;
       }
       
@@ -11809,6 +11845,10 @@ public final class HBaseProtos {
           to_bitField0_ |= 0x00000008;
         }
         result.type_ = type_;
+        if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+          to_bitField0_ |= 0x00000010;
+        }
+        result.version_ = version_;
         result.bitField0_ = to_bitField0_;
         onBuilt();
         return result;
@@ -11837,6 +11877,9 @@ public final class HBaseProtos {
         if (other.hasType()) {
           setType(other.getType());
         }
+        if (other.hasVersion()) {
+          setVersion(other.getVersion());
+        }
         this.mergeUnknownFields(other.getUnknownFields());
         return this;
       }
@@ -11898,6 +11941,11 @@ public final class HBaseProtos {
               }
               break;
             }
+            case 40: {
+              bitField0_ |= 0x00000010;
+              version_ = input.readInt32();
+              break;
+            }
           }
         }
       }
@@ -12021,6 +12069,27 @@ public final class HBaseProtos {
         return this;
       }
       
+      // optional int32 version = 5;
+      private int version_ ;
+      public boolean hasVersion() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      public int getVersion() {
+        return version_;
+      }
+      public Builder setVersion(int value) {
+        bitField0_ |= 0x00000010;
+        version_ = value;
+        onChanged();
+        return this;
+      }
+      public Builder clearVersion() {
+        bitField0_ = (bitField0_ & ~0x00000010);
+        version_ = 0;
+        onChanged();
+        return this;
+      }
+      
       // @@protoc_insertion_point(builder_scope:SnapshotDescription)
     }
     
@@ -12174,18 +12243,19 @@ public final class HBaseProtos {
       "value\030\002 \002(\t\",\n\rNameBytesPair\022\014\n\004name\030\001 \002" +
       "(\t\022\r\n\005value\030\002 \001(\014\"/\n\016BytesBytesPair\022\r\n\005f" +
       "irst\030\001 \002(\014\022\016\n\006second\030\002 \002(\014\",\n\rNameInt64P" +
-      "air\022\014\n\004name\030\001 \001(\t\022\r\n\005value\030\002 \001(\003\"\242\001\n\023Sna" +
+      "air\022\014\n\004name\030\001 \001(\t\022\r\n\005value\030\002 \001(\003\"\301\001\n\023Sna" +
       "pshotDescription\022\014\n\004name\030\001 \002(\t\022\r\n\005table\030" +
       "\002 \001(\t\022\027\n\014creationTime\030\003 \001(\003:\0010\0222\n\004type\030\004" +
       " \001(\0162\031.SnapshotDescription.Type:\tTIMESTA" +
-      "MP\"!\n\004Type\022\r\n\tTIMESTAMP\020\000\022\n\n\006GLOBAL\020\001*r\n" +
+      "MP\022\017\n\007version\030\005 \001(\005\"/\n\004Type\022\014\n\010DISABLED\020" +
-      "\013CompareType\022\010\n\004LESS\020\000\022\021\n\rLESS_OR_EQUAL\020" +
+      "\000\022\r\n\tTIMESTAMP\020\001\022\n\n\006GLOBAL\020\002*r\n\013CompareT" +
-      "\001\022\t\n\005EQUAL\020\002\022\r\n\tNOT_EQUAL\020\003\022\024\n\020GREATER_O",
+      "ype\022\010\n\004LESS\020\000\022\021\n\rLESS_OR_EQUAL\020\001\022\t\n\005EQUA",
-      "R_EQUAL\020\004\022\013\n\007GREATER\020\005\022\t\n\005NO_OP\020\006*_\n\007Key" +
+      "L\020\002\022\r\n\tNOT_EQUAL\020\003\022\024\n\020GREATER_OR_EQUAL\020\004" +
-      "Type\022\013\n\007MINIMUM\020\000\022\007\n\003PUT\020\004\022\n\n\006DELETE\020\010\022\021" +
+      "\022\013\n\007GREATER\020\005\022\t\n\005NO_OP\020\006*_\n\007KeyType\022\013\n\007M" +
-      "\n\rDELETE_COLUMN\020\014\022\021\n\rDELETE_FAMILY\020\016\022\014\n\007" +
+      "INIMUM\020\000\022\007\n\003PUT\020\004\022\n\n\006DELETE\020\010\022\021\n\rDELETE_" +
-      "MAXIMUM\020\377\001B>\n*org.apache.hadoop.hbase.pr" +
+      "COLUMN\020\014\022\021\n\rDELETE_FAMILY\020\016\022\014\n\007MAXIMUM\020\377" +
-      "otobuf.generatedB\013HBaseProtosH\001\240\001\001"
+      "\001B>\n*org.apache.hadoop.hbase.protobuf.ge" +
+      "neratedB\013HBaseProtosH\001\240\001\001"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
       new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
@@ -12333,7 +12403,7 @@ public final class HBaseProtos {
           internal_static_SnapshotDescription_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_SnapshotDescription_descriptor,
-              new java.lang.String[] { "Name", "Table", "CreationTime", "Type", },
+              new java.lang.String[] { "Name", "Table", "CreationTime", "Type", "Version", },
               org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.class,
               org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Builder.class);
           return null;

hbase-protocol/src/main/java/org/apache/hadoop/hbase/protobuf/generated/MasterAdminProtos.java

@@ -14840,9 +14840,9 @@ public final class MasterAdminProtos {
   public interface TakeSnapshotResponseOrBuilder
       extends com.google.protobuf.MessageOrBuilder {
     
-    // required int64 expectedTime = 1;
+    // required int64 expectedTimeout = 1;
-    boolean hasExpectedTime();
+    boolean hasExpectedTimeout();
-    long getExpectedTime();
+    long getExpectedTimeout();
   }
   public static final class TakeSnapshotResponse extends
       com.google.protobuf.GeneratedMessage
@@ -14873,25 +14873,25 @@ public final class MasterAdminProtos {
     }
     
     private int bitField0_;
-    // required int64 expectedTime = 1;
+    // required int64 expectedTimeout = 1;
-    public static final int EXPECTEDTIME_FIELD_NUMBER = 1;
+    public static final int EXPECTEDTIMEOUT_FIELD_NUMBER = 1;
-    private long expectedTime_;
+    private long expectedTimeout_;
-    public boolean hasExpectedTime() {
+    public boolean hasExpectedTimeout() {
       return ((bitField0_ & 0x00000001) == 0x00000001);
     }
-    public long getExpectedTime() {
+    public long getExpectedTimeout() {
-      return expectedTime_;
+      return expectedTimeout_;
     }
     
     private void initFields() {
-      expectedTime_ = 0L;
+      expectedTimeout_ = 0L;
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
       byte isInitialized = memoizedIsInitialized;
       if (isInitialized != -1) return isInitialized == 1;
       
-      if (!hasExpectedTime()) {
+      if (!hasExpectedTimeout()) {
         memoizedIsInitialized = 0;
         return false;
       }
@@ -14903,7 +14903,7 @@ public final class MasterAdminProtos {
                         throws java.io.IOException {
       getSerializedSize();
       if (((bitField0_ & 0x00000001) == 0x00000001)) {
-        output.writeInt64(1, expectedTime_);
+        output.writeInt64(1, expectedTimeout_);
       }
       getUnknownFields().writeTo(output);
     }
@@ -14916,7 +14916,7 @@ public final class MasterAdminProtos {
       size = 0;
       if (((bitField0_ & 0x00000001) == 0x00000001)) {
         size += com.google.protobuf.CodedOutputStream
-          .computeInt64Size(1, expectedTime_);
+          .computeInt64Size(1, expectedTimeout_);
       }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
@@ -14941,10 +14941,10 @@ public final class MasterAdminProtos {
       org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.TakeSnapshotResponse other = (org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.TakeSnapshotResponse) obj;
       
       boolean result = true;
-      result = result && (hasExpectedTime() == other.hasExpectedTime());
+      result = result && (hasExpectedTimeout() == other.hasExpectedTimeout());
-      if (hasExpectedTime()) {
+      if (hasExpectedTimeout()) {
-        result = result && (getExpectedTime()
+        result = result && (getExpectedTimeout()
-            == other.getExpectedTime());
+            == other.getExpectedTimeout());
       }
       result = result &&
           getUnknownFields().equals(other.getUnknownFields());
@@ -14955,9 +14955,9 @@ public final class MasterAdminProtos {
     public int hashCode() {
       int hash = 41;
       hash = (19 * hash) + getDescriptorForType().hashCode();
-      if (hasExpectedTime()) {
+      if (hasExpectedTimeout()) {
-        hash = (37 * hash) + EXPECTEDTIME_FIELD_NUMBER;
+        hash = (37 * hash) + EXPECTEDTIMEOUT_FIELD_NUMBER;
-        hash = (53 * hash) + hashLong(getExpectedTime());
+        hash = (53 * hash) + hashLong(getExpectedTimeout());
       }
       hash = (29 * hash) + getUnknownFields().hashCode();
       return hash;
@@ -15075,7 +15075,7 @@ public final class MasterAdminProtos {
       
       public Builder clear() {
         super.clear();
-        expectedTime_ = 0L;
+        expectedTimeout_ = 0L;
         bitField0_ = (bitField0_ & ~0x00000001);
         return this;
       }
@@ -15118,7 +15118,7 @@ public final class MasterAdminProtos {
         if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
           to_bitField0_ |= 0x00000001;
         }
-        result.expectedTime_ = expectedTime_;
+        result.expectedTimeout_ = expectedTimeout_;
         result.bitField0_ = to_bitField0_;
         onBuilt();
         return result;
@@ -15135,15 +15135,15 @@ public final class MasterAdminProtos {
       
       public Builder mergeFrom(org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.TakeSnapshotResponse other) {
         if (other == org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.TakeSnapshotResponse.getDefaultInstance()) return this;
-        if (other.hasExpectedTime()) {
+        if (other.hasExpectedTimeout()) {
-          setExpectedTime(other.getExpectedTime());
+          setExpectedTimeout(other.getExpectedTimeout());
         }
         this.mergeUnknownFields(other.getUnknownFields());
         return this;
       }
       
       public final boolean isInitialized() {
-        if (!hasExpectedTime()) {
+        if (!hasExpectedTimeout()) {
           
           return false;
         }
@@ -15175,7 +15175,7 @@ public final class MasterAdminProtos {
             }
             case 8: {
               bitField0_ |= 0x00000001;
-              expectedTime_ = input.readInt64();
+              expectedTimeout_ = input.readInt64();
               break;
             }
           }
@@ -15184,23 +15184,23 @@ public final class MasterAdminProtos {
       
       private int bitField0_;
       
-      // required int64 expectedTime = 1;
+      // required int64 expectedTimeout = 1;
-      private long expectedTime_ ;
+      private long expectedTimeout_ ;
-      public boolean hasExpectedTime() {
+      public boolean hasExpectedTimeout() {
         return ((bitField0_ & 0x00000001) == 0x00000001);
       }
-      public long getExpectedTime() {
+      public long getExpectedTimeout() {
-        return expectedTime_;
+        return expectedTimeout_;
       }
-      public Builder setExpectedTime(long value) {
+      public Builder setExpectedTimeout(long value) {
         bitField0_ |= 0x00000001;
-        expectedTime_ = value;
+        expectedTimeout_ = value;
         onChanged();
         return this;
       }
-      public Builder clearExpectedTime() {
+      public Builder clearExpectedTimeout() {
         bitField0_ = (bitField0_ & ~0x00000001);
-        expectedTime_ = 0L;
+        expectedTimeout_ = 0L;
         onChanged();
         return this;
       }
@@ -19883,56 +19883,57 @@ public final class MasterAdminProtos {
       "anitorEnabledRequest\"0\n\037IsCatalogJanitor",
       "EnabledResponse\022\r\n\005value\030\001 \002(\010\"=\n\023TakeSn" +
       "apshotRequest\022&\n\010snapshot\030\001 \002(\0132\024.Snapsh" +
-      "otDescription\",\n\024TakeSnapshotResponse\022\024\n" +
+      "otDescription\"/\n\024TakeSnapshotResponse\022\027\n" +
-      "\014expectedTime\030\001 \002(\003\"\025\n\023ListSnapshotReque" +
+      "\017expectedTimeout\030\001 \002(\003\"\025\n\023ListSnapshotRe" +
-      "st\"?\n\024ListSnapshotResponse\022\'\n\tsnapshots\030" +
+      "quest\"?\n\024ListSnapshotResponse\022\'\n\tsnapsho" +
-      "\001 \003(\0132\024.SnapshotDescription\"?\n\025DeleteSna" +
+      "ts\030\001 \003(\0132\024.SnapshotDescription\"?\n\025Delete" +
-      "pshotRequest\022&\n\010snapshot\030\001 \002(\0132\024.Snapsho" +
+      "SnapshotRequest\022&\n\010snapshot\030\001 \002(\0132\024.Snap" +
-      "tDescription\"\030\n\026DeleteSnapshotResponse\"?" +
+      "shotDescription\"\030\n\026DeleteSnapshotRespons" +
-      "\n\025IsSnapshotDoneRequest\022&\n\010snapshot\030\001 \001(" +
+      "e\"?\n\025IsSnapshotDoneRequest\022&\n\010snapshot\030\001" +
-      "\0132\024.SnapshotDescription\"U\n\026IsSnapshotDon",
+      " \001(\0132\024.SnapshotDescription\"U\n\026IsSnapshot",
-      "eResponse\022\023\n\004done\030\001 \001(\010:\005false\022&\n\010snapsh" +
+      "DoneResponse\022\023\n\004done\030\001 \001(\010:\005false\022&\n\010sna" +
-      "ot\030\002 \001(\0132\024.SnapshotDescription2\376\013\n\022Maste" +
+      "pshot\030\002 \001(\0132\024.SnapshotDescription2\376\013\n\022Ma" +
-      "rAdminService\0222\n\taddColumn\022\021.AddColumnRe" +
+      "sterAdminService\0222\n\taddColumn\022\021.AddColum" +
-      "quest\032\022.AddColumnResponse\022;\n\014deleteColum" +
+      "nRequest\032\022.AddColumnResponse\022;\n\014deleteCo" +
-      "n\022\024.DeleteColumnRequest\032\025.DeleteColumnRe" +
+      "lumn\022\024.DeleteColumnRequest\032\025.DeleteColum" +
-      "sponse\022;\n\014modifyColumn\022\024.ModifyColumnReq" +
+      "nResponse\022;\n\014modifyColumn\022\024.ModifyColumn" +
-      "uest\032\025.ModifyColumnResponse\0225\n\nmoveRegio" +
+      "Request\032\025.ModifyColumnResponse\0225\n\nmoveRe" +
-      "n\022\022.MoveRegionRequest\032\023.MoveRegionRespon" +
+      "gion\022\022.MoveRegionRequest\032\023.MoveRegionRes" +
-      "se\022;\n\014assignRegion\022\024.AssignRegionRequest" +
+      "ponse\022;\n\014assignRegion\022\024.AssignRegionRequ" +
-      "\032\025.AssignRegionResponse\022A\n\016unassignRegio",
+      "est\032\025.AssignRegionResponse\022A\n\016unassignRe",
-      "n\022\026.UnassignRegionRequest\032\027.UnassignRegi" +
+      "gion\022\026.UnassignRegionRequest\032\027.UnassignR" +
-      "onResponse\022>\n\rofflineRegion\022\025.OfflineReg" +
+      "egionResponse\022>\n\rofflineRegion\022\025.Offline" +
-      "ionRequest\032\026.OfflineRegionResponse\0228\n\013de" +
+      "RegionRequest\032\026.OfflineRegionResponse\0228\n" +
-      "leteTable\022\023.DeleteTableRequest\032\024.DeleteT" +
+      "\013deleteTable\022\023.DeleteTableRequest\032\024.Dele" +
-      "ableResponse\0228\n\013enableTable\022\023.EnableTabl" +
+      "teTableResponse\0228\n\013enableTable\022\023.EnableT" +
-      "eRequest\032\024.EnableTableResponse\022;\n\014disabl" +
+      "ableRequest\032\024.EnableTableResponse\022;\n\014dis" +
-      "eTable\022\024.DisableTableRequest\032\025.DisableTa" +
+      "ableTable\022\024.DisableTableRequest\032\025.Disabl" +
-      "bleResponse\0228\n\013modifyTable\022\023.ModifyTable" +
+      "eTableResponse\0228\n\013modifyTable\022\023.ModifyTa" +
-      "Request\032\024.ModifyTableResponse\0228\n\013createT" +
+      "bleRequest\032\024.ModifyTableResponse\0228\n\013crea" +
-      "able\022\023.CreateTableRequest\032\024.CreateTableR",
+      "teTable\022\023.CreateTableRequest\032\024.CreateTab",
-      "esponse\022/\n\010shutdown\022\020.ShutdownRequest\032\021." +
+      "leResponse\022/\n\010shutdown\022\020.ShutdownRequest" +
-      "ShutdownResponse\0225\n\nstopMaster\022\022.StopMas" +
+      "\032\021.ShutdownResponse\0225\n\nstopMaster\022\022.Stop" +
-      "terRequest\032\023.StopMasterResponse\022,\n\007balan" +
+      "MasterRequest\032\023.StopMasterResponse\022,\n\007ba" +
-      "ce\022\017.BalanceRequest\032\020.BalanceResponse\022M\n" +
+      "lance\022\017.BalanceRequest\032\020.BalanceResponse" +
-      "\022setBalancerRunning\022\032.SetBalancerRunning" +
+      "\022M\n\022setBalancerRunning\022\032.SetBalancerRunn" +
-      "Request\032\033.SetBalancerRunningResponse\022;\n\016" +
+      "ingRequest\032\033.SetBalancerRunningResponse\022" +
-      "runCatalogScan\022\023.CatalogScanRequest\032\024.Ca" +
+      ";\n\016runCatalogScan\022\023.CatalogScanRequest\032\024" +
-      "talogScanResponse\022S\n\024enableCatalogJanito" +
+      ".CatalogScanResponse\022S\n\024enableCatalogJan" +
-      "r\022\034.EnableCatalogJanitorRequest\032\035.Enable" +
+      "itor\022\034.EnableCatalogJanitorRequest\032\035.Ena" +
-      "CatalogJanitorResponse\022\\\n\027isCatalogJanit",
+      "bleCatalogJanitorResponse\022\\\n\027isCatalogJa",
-      "orEnabled\022\037.IsCatalogJanitorEnabledReque" +
+      "nitorEnabled\022\037.IsCatalogJanitorEnabledRe" +
-      "st\032 .IsCatalogJanitorEnabledResponse\022L\n\021" +
+      "quest\032 .IsCatalogJanitorEnabledResponse\022" +
-      "execMasterService\022\032.CoprocessorServiceRe" +
+      "L\n\021execMasterService\022\032.CoprocessorServic" +
-      "quest\032\033.CoprocessorServiceResponse\0227\n\010sn" +
+      "eRequest\032\033.CoprocessorServiceResponse\0227\n" +
-      "apshot\022\024.TakeSnapshotRequest\032\025.TakeSnaps" +
+      "\010snapshot\022\024.TakeSnapshotRequest\032\025.TakeSn" +
-      "hotResponse\022<\n\rlistSnapshots\022\024.ListSnaps" +
+      "apshotResponse\022<\n\rlistSnapshots\022\024.ListSn" +
-      "hotRequest\032\025.ListSnapshotResponse\022A\n\016del" +
+      "apshotRequest\032\025.ListSnapshotResponse\022A\n\016" +
-      "eteSnapshot\022\026.DeleteSnapshotRequest\032\027.De" +
+      "deleteSnapshot\022\026.DeleteSnapshotRequest\032\027" +
-      "leteSnapshotResponse\022A\n\016isSnapshotDone\022\026" +
+      ".DeleteSnapshotResponse\022A\n\016isSnapshotDon" +
-      ".IsSnapshotDoneRequest\032\027.IsSnapshotDoneR",
+      "e\022\026.IsSnapshotDoneRequest\032\027.IsSnapshotDo",
-      "esponseBG\n*org.apache.hadoop.hbase.proto" +
+      "neResponseBG\n*org.apache.hadoop.hbase.pr" +
-      "buf.generatedB\021MasterAdminProtosH\001\210\001\001\240\001\001"
+      "otobuf.generatedB\021MasterAdminProtosH\001\210\001\001" +
+      "\240\001\001"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
       new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
@@ -20256,7 +20257,7 @@ public final class MasterAdminProtos {
           internal_static_TakeSnapshotResponse_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_TakeSnapshotResponse_descriptor,
-              new java.lang.String[] { "ExpectedTime", },
+              new java.lang.String[] { "ExpectedTimeout", },
               org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.TakeSnapshotResponse.class,
               org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.TakeSnapshotResponse.Builder.class);
           internal_static_ListSnapshotRequest_descriptor =

hbase-protocol/src/main/protobuf/MasterAdmin.proto

@@ -182,7 +182,7 @@ message TakeSnapshotRequest{
 }
 
 message TakeSnapshotResponse{
-	required int64 expectedTime = 1;
+	required int64 expectedTimeout = 1;
 }
 
 message ListSnapshotRequest{

hbase-protocol/src/main/protobuf/hbase.proto

@@ -277,8 +277,10 @@ message SnapshotDescription {
 	optional string table = 2; // not needed for delete, but checked for in taking snapshot
 	optional int64 creationTime = 3 [default = 0];
 	enum Type {
-		TIMESTAMP = 0;
+		DISABLED = 0;
-		GLOBAL = 1;
+		TIMESTAMP = 1;
+		GLOBAL = 2;
 	}
 	optional Type type = 4 [default = TIMESTAMP];
+	optional int32 version = 5;
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/MasterAdminProtocol.java

@@ -74,7 +74,8 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsMasterRunningRe
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsMasterRunningResponse;
 import org.apache.hadoop.hbase.security.KerberosInfo;
 import org.apache.hadoop.hbase.security.TokenInfo;
-import org.apache.hadoop.hbase.snapshot.SnapshotCreationException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.snapshot.exception.UnknownSnapshotException;
 
 import com.google.protobuf.RpcController;
 import com.google.protobuf.ServiceException;

hbase-server/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java

@@ -103,10 +103,10 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterMonitorProtos.GetSchemaA
 import org.apache.hadoop.hbase.protobuf.generated.MasterMonitorProtos.GetTableDescriptorsRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterMonitorProtos.GetTableDescriptorsResponse;
 import org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;
-import org.apache.hadoop.hbase.snapshot.HBaseSnapshotException;
-import org.apache.hadoop.hbase.snapshot.SnapshotCreationException;
 import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
-import org.apache.hadoop.hbase.snapshot.UnknownSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.snapshot.exception.UnknownSnapshotException;
 import org.apache.hadoop.hbase.util.Addressing;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
@@ -2217,14 +2217,15 @@ public class HBaseAdmin implements Abortable, Closeable {
     TakeSnapshotResponse response = takeSnapshotAsync(snapshot);
     final IsSnapshotDoneRequest request = IsSnapshotDoneRequest.newBuilder().setSnapshot(snapshot)
         .build();
-    IsSnapshotDoneResponse done = IsSnapshotDoneResponse.newBuilder().buildPartial();
+    IsSnapshotDoneResponse done = null;
     long start = EnvironmentEdgeManager.currentTimeMillis();
-    long max = response.getExpectedTime();
+    long max = response.getExpectedTimeout();
     long maxPauseTime = max / this.numRetries;
     int tries = 0;
     LOG.debug("Waiting a max of " + max + " ms for snapshot to complete. (max " + maxPauseTime
         + " ms per retry)");
-    while ((EnvironmentEdgeManager.currentTimeMillis() - start) < max && !done.getDone()) {
+    while (tries == 0
+        || ((EnvironmentEdgeManager.currentTimeMillis() - start) < max && !done.getDone())) {
       try {
         // sleep a backoff <= pauseTime amount
         long sleep = getPauseTime(tries++);
@@ -2245,9 +2246,10 @@ public class HBaseAdmin implements Abortable, Closeable {
         }
       });
     }
+    ;
     if (!done.getDone()) {
       throw new SnapshotCreationException("Snapshot '" + snapshot.getName()
-          + "' wasn't completed in expectedTime:" + max + " ms");
+          + "' wasn't completed in expectedTime:" + max + " ms", snapshot);
     }
   }
 

hbase-server/src/main/java/org/apache/hadoop/hbase/executor/EventHandler.java

@@ -135,6 +135,7 @@ public abstract class EventHandler implements Runnable, Comparable<Runnable> {
     C_M_DELETE_FAMILY         (45, null), // Client asking Master to delete family of table
     C_M_MODIFY_FAMILY         (46, null), // Client asking Master to modify family of table
     C_M_CREATE_TABLE          (47, ExecutorType.MASTER_TABLE_OPERATIONS),   // Client asking Master to create a table
+    C_M_SNAPSHOT_TABLE        (48, ExecutorType.MASTER_TABLE_OPERATIONS),   // Client asking Master to snapshot an offline table
 
     // Updates from master to ZK. This is done by the master and there is
     // nothing to process by either Master or RS

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -18,6 +18,7 @@
  */
 package org.apache.hadoop.hbase.master;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
@@ -49,6 +50,9 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Abortable;
 import org.apache.hadoop.hbase.Chore;
@@ -103,6 +107,7 @@ import org.apache.hadoop.hbase.master.handler.TableAddFamilyHandler;
 import org.apache.hadoop.hbase.master.handler.TableDeleteFamilyHandler;
 import org.apache.hadoop.hbase.master.handler.TableEventHandler;
 import org.apache.hadoop.hbase.master.handler.TableModifyFamilyHandler;
+import org.apache.hadoop.hbase.master.snapshot.manage.SnapshotManager;
 import org.apache.hadoop.hbase.monitoring.MemoryBoundedLogMessageBuffer;
 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
 import org.apache.hadoop.hbase.monitoring.TaskMonitor;
@@ -113,6 +118,7 @@ import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.NameStringPair;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.RegionSpecifier.RegionSpecifierType;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
 import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.AddColumnRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.AddColumnResponse;
 import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.AssignRegionRequest;
@@ -178,10 +184,18 @@ import org.apache.hadoop.hbase.protobuf.generated.RegionServerStatusProtos.Repor
 import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.replication.regionserver.Replication;
 import org.apache.hadoop.hbase.security.User;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotDoesNotExistException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotExistsException;
+import org.apache.hadoop.hbase.snapshot.exception.TablePartiallyOpenException;
+import org.apache.hadoop.hbase.snapshot.exception.UnknownSnapshotException;
 import org.apache.hadoop.hbase.trace.SpanReceiverHost;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.CompressionTest;
 import org.apache.hadoop.hbase.util.FSTableDescriptors;
+import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.HFileArchiveUtil;
 import org.apache.hadoop.hbase.util.HasThread;
 import org.apache.hadoop.hbase.util.InfoServer;
@@ -201,8 +215,6 @@ import org.apache.hadoop.metrics.util.MBeanUtil;
 import org.apache.hadoop.net.DNS;
 import org.apache.zookeeper.KeeperException;
 import org.apache.zookeeper.Watcher;
-import org.apache.hadoop.hbase.trace.SpanReceiverHost;
-import org.apache.hadoop.hbase.util.FSUtils;
 
 import com.google.protobuf.RpcController;
 import com.google.protobuf.ServiceException;
@@ -327,8 +339,12 @@ Server {
 
   private SpanReceiverHost spanReceiverHost;
 
+
   private Map<String, Service> coprocessorServiceHandlers = Maps.newHashMap();
 
+  // monitor for snapshot of hbase tables
+  private SnapshotManager snapshotManager;
+
   /**
    * Initializes the HMaster. The steps are as follows:
    * <p>
@@ -503,6 +519,7 @@ Server {
       if (this.serverManager != null) this.serverManager.stop();
       if (this.assignmentManager != null) this.assignmentManager.stop();
       if (this.fileSystemManager != null) this.fileSystemManager.stop();
+      if (this.snapshotManager != null) this.snapshotManager.stop("server shutting down.");
       this.zooKeeper.close();
     }
     LOG.info("HMaster main thread exiting");
@@ -567,6 +584,10 @@ Server {
         ", sessionid=0x" +
         Long.toHexString(this.zooKeeper.getRecoverableZooKeeper().getSessionId()) +
         ", cluster-up flag was=" + wasUp);
+
+    // create the snapshot monitor
+    // TODO should this be config based?
+    this.snapshotManager = new SnapshotManager(this, zooKeeper, this.executorService);
   }
 
   /**
@@ -2409,31 +2430,226 @@ Server {
     return this.hfileCleaner;
   }
 
-  @Override
+  /**
-  public TakeSnapshotResponse snapshot(RpcController controller, TakeSnapshotRequest request)
+   * Exposed for TESTING!
-      throws ServiceException {
+   * @return the underlying snapshot manager
-    throw new ServiceException(new UnsupportedOperationException(
+   */
-        "Snapshots are not implemented yet."));
+  SnapshotManager getSnapshotManagerForTesting() {
+    return this.snapshotManager;
   }
 
+  @Override
+  public TakeSnapshotResponse snapshot(RpcController controller, TakeSnapshotRequest request)
+      throws ServiceException {
+    LOG.debug("Starting snapshot for:" + request);
+    // get the snapshot information
+    SnapshotDescription snapshot = SnapshotDescriptionUtils.validate(request.getSnapshot(),
+      this.conf);
+
+    // check to see if we already completed the snapshot
+    if (isSnapshotCompleted(snapshot)) {
+      throw new ServiceException(new SnapshotExistsException("Snapshot '" + snapshot.getName()
+          + "' already stored on the filesystem.", snapshot));
+    }
+
+    LOG.debug("No existing snapshot, attempting snapshot...");
+
+    // check to see if the table exists
+    HTableDescriptor desc = null;
+    try {
+      desc = this.tableDescriptors.get(snapshot.getTable());
+    } catch (FileNotFoundException e) {
+      String msg = "Table:" + snapshot.getTable() + " info doesn't exist!";
+      LOG.error(msg);
+      throw new ServiceException(new SnapshotCreationException(msg, e, snapshot));
+    } catch (IOException e) {
+      throw new ServiceException(new SnapshotCreationException(
+          "Error while geting table description for table " + snapshot.getTable(), e, snapshot));
+    }
+    if (desc == null) {
+      throw new ServiceException(new SnapshotCreationException("Table '" + snapshot.getTable()
+          + "' doesn't exist, can't take snapshot.", snapshot));
+    }
+
+    // set the snapshot version, now that we are ready to take it
+    snapshot = snapshot.toBuilder().setVersion(SnapshotDescriptionUtils.SNAPSHOT_LAYOUT_VERSION)
+        .build();
+
+    // if the table is enabled, then have the RS run actually the snapshot work
+    if (this.assignmentManager.getZKTable().isEnabledTable(snapshot.getTable())) {
+      LOG.debug("Table enabled, starting distributed snapshot.");
+      throw new ServiceException(new UnsupportedOperationException(
+          "Enabled table snapshots are not yet supported"));
+    }
+    // For disabled table, snapshot is created by the master
+    else if (this.assignmentManager.getZKTable().isDisabledTable(snapshot.getTable())) {
+      LOG.debug("Table is disabled, running snapshot entirely on master.");
+      try {
+        snapshotManager.snapshotDisabledTable(snapshot);
+      } catch (HBaseSnapshotException e) {
+        throw new ServiceException(e);
+      }
+
+      LOG.debug("Started snapshot: " + snapshot);
+    } else {
+      LOG.error("Can't snapshot table '" + snapshot.getTable()
+          + "', isn't open or closed, we don't know what to do!");
+      throw new ServiceException(new SnapshotCreationException(
+          "Table is not entirely open or closed", new TablePartiallyOpenException(
+              snapshot.getTable() + " isn't fully open."), snapshot));
+    }
+    // send back the max amount of time the client should wait for the snapshot to complete
+    long waitTime = SnapshotDescriptionUtils.getMaxMasterTimeout(conf, snapshot.getType(),
+      SnapshotDescriptionUtils.DEFAULT_MAX_WAIT_TIME);
+    return TakeSnapshotResponse.newBuilder().setExpectedTimeout(waitTime).build();
+  }
+
+  /**
+   * List the currently available/stored snapshots. Any in-progress snapshots are ignored
+   */
   @Override
   public ListSnapshotResponse listSnapshots(RpcController controller, ListSnapshotRequest request)
       throws ServiceException {
-    throw new ServiceException(new UnsupportedOperationException(
+    try {
-        "Snapshots are not implemented yet."));
+      ListSnapshotResponse.Builder builder = ListSnapshotResponse.newBuilder();
+
+      // first create the snapshot description and check to see if it exists
+      Path snapshotDir = SnapshotDescriptionUtils.getSnapshotsDir(this.getMasterFileSystem()
+          .getRootDir());
+
+      // if there are no snapshots, return an empty list
+      if (!this.getMasterFileSystem().getFileSystem().exists(snapshotDir)) {
+        return builder.build();
+      }
+
+      FileSystem fs = this.getMasterFileSystem().getFileSystem();
+
+      // ignore all the snapshots in progress
+      FileStatus[] snapshots = fs.listStatus(snapshotDir,
+        new SnapshotDescriptionUtils.CompletedSnaphotDirectoriesFilter(fs));
+      // look through all the completed snapshots
+      for (FileStatus snapshot : snapshots) {
+        Path info = new Path(snapshot.getPath(), SnapshotDescriptionUtils.SNAPSHOTINFO_FILE);
+        // if the snapshot is bad
+        if (!fs.exists(info)) {
+          LOG.error("Snapshot information for " + snapshot.getPath() + " doesn't exist");
+          continue;
+        }
+        FSDataInputStream in = null;
+        try {
+          in = fs.open(info);
+          SnapshotDescription desc = SnapshotDescription.parseFrom(in);
+          builder.addSnapshots(desc);
+        } catch (IOException e) {
+          LOG.warn("Found a corrupted snapshot " + snapshot.getPath(), e);
+        } finally {
+          if (in != null) {
+            in.close();
+          }
+        }
+      }
+      return builder.build();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
   }
 
   @Override
   public DeleteSnapshotResponse deleteSnapshot(RpcController controller,
       DeleteSnapshotRequest request) throws ServiceException {
-    throw new ServiceException(new UnsupportedOperationException(
+    try {
-        "Snapshots are not implemented yet."));
+      // check to see if it is completed
+      if (!isSnapshotCompleted(request.getSnapshot())) {
+        throw new SnapshotDoesNotExistException(request.getSnapshot());
+      }
+
+      String snapshotName = request.getSnapshot().getName();
+      LOG.debug("Deleting snapshot: " + snapshotName);
+      // first create the snapshot description and check to see if it exists
+      Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, this
+          .getMasterFileSystem().getRootDir());
+
+      // delete the existing snapshot
+      if (!this.getMasterFileSystem().getFileSystem().delete(snapshotDir, true)) {
+        throw new ServiceException("Failed to delete snapshot directory: " + snapshotDir);
+      }
+      return DeleteSnapshotResponse.newBuilder().build();
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
   }
 
   @Override
   public IsSnapshotDoneResponse isSnapshotDone(RpcController controller,
       IsSnapshotDoneRequest request) throws ServiceException {
-    throw new ServiceException(new UnsupportedOperationException(
+    LOG.debug("Checking to see if snapshot from request:" + request + " is done");
-        "Snapshots are not implemented yet."));
+    try {
+      // check the request to make sure it has a snapshot
+      if (!request.hasSnapshot()) {
+        throw new UnknownSnapshotException(
+            "No snapshot name passed in request, can't figure out which snapshot you want to check.");
+      }
+
+      SnapshotDescription expected = request.getSnapshot();
+      IsSnapshotDoneResponse.Builder builder = IsSnapshotDoneResponse.newBuilder();
+
+      // check to see if the sentinel exists
+      SnapshotSentinel sentinel = this.snapshotManager.getCurrentSnapshotSentinel();
+      if (sentinel != null) {
+
+        // pass on any failure we find in the sentinel
+        HBaseSnapshotException e = sentinel.getExceptionIfFailed();
+        if (e != null) throw e;
+
+        // get the current snapshot and compare it against the requested
+        SnapshotDescription snapshot = sentinel.getSnapshot();
+        LOG.debug("Have a snapshot to compare:" + snapshot);
+        if (expected.getName().equals(snapshot.getName())) {
+          LOG.trace("Running snapshot (" + snapshot.getName() + ") does match request:"
+              + expected.getName());
+
+          // check to see if we are done
+          if (sentinel.isFinished()) {
+            builder.setDone(true);
+            LOG.debug("Snapshot " + snapshot + " has completed, notifying client.");
+          } else if (LOG.isDebugEnabled()) {
+            LOG.debug("Sentinel isn't finished with snapshot!");
+          }
+          return builder.build();
+        }
+
+      }
+
+      // check to see if the snapshot is already on the fs
+      if (!isSnapshotCompleted(expected)) {
+        throw new UnknownSnapshotException("Snapshot:" + expected.getName()
+            + " is not currently running or one of the known completed snapshots.");
+      }
+
+      builder.setDone(true);
+      return builder.build();
+    } catch (HBaseSnapshotException e) {
+      throw new ServiceException(e);
+    }
+  }
+
+  /**
+   * Check to see if the snapshot is one of the currently completed snapshots
+   * @param expected snapshot to check
+   * @return <tt>true</tt> if the snapshot is stored on the {@link FileSystem}, <tt>false</tt> if is
+   *         not stored
+   * @throws IOException if the filesystem throws an unexpected exception
+   */
+  private boolean isSnapshotCompleted(SnapshotDescription snapshot) throws ServiceException {
+    final Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshot, this
+        .getMasterFileSystem().getRootDir());
+    FileSystem fs = this.getMasterFileSystem().getFileSystem();
+
+    // check to see if the snapshot already exists
+    try {
+      return fs.exists(snapshotDir);
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
   }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/SnapshotSentinel.java

@@ -0,0 +1,52 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hbase.Stoppable;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+
+/**
+ * Watch the current snapshot under process
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public interface SnapshotSentinel extends Stoppable {
+
+  /**
+   * Check to see if the snapshot is finished, where finished may be success or failure.
+   * @return <tt>false</tt> if the snapshot is still in progress, <tt>true</tt> if the snapshot has
+   *         finished
+   */
+  public boolean isFinished();
+
+  /**
+   * @return the description of the snapshot being run
+   */
+  public SnapshotDescription getSnapshot();
+
+  /**
+   * Get the exception that caused the snapshot to fail, if the snapshot has failed.
+   * @return <tt>null</tt> if the snapshot succeeded, or the {@link HBaseSnapshotException} that
+   *         caused the snapshot to fail.
+   */
+  public HBaseSnapshotException getExceptionIfFailed();
+
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/DisabledTableSnapshotHandler.java

@@ -0,0 +1,236 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master.snapshot;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.Server;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.catalog.MetaReader;
+import org.apache.hadoop.hbase.executor.EventHandler;
+import org.apache.hadoop.hbase.master.MasterServices;
+import org.apache.hadoop.hbase.master.SnapshotSentinel;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.server.errorhandling.OperationAttemptTimer;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.server.snapshot.task.CopyRecoveredEditsTask;
+import org.apache.hadoop.hbase.server.snapshot.task.ReferenceRegionHFilesTask;
+import org.apache.hadoop.hbase.server.snapshot.task.TableInfoCopyTask;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hbase.util.Pair;
+
+/**
+ * Take a snapshot of a disabled table.
+ * <p>
+ * Table must exist when taking the snapshot, or results are undefined.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public class DisabledTableSnapshotHandler extends EventHandler implements SnapshotSentinel {
+  private static final Log LOG = LogFactory.getLog(DisabledTableSnapshotHandler.class);
+
+  private volatile boolean stopped = false;
+
+  protected final Configuration conf;
+  protected final FileSystem fs;
+  protected final Path rootDir;
+
+  private final MasterServices masterServices;
+
+  private final SnapshotDescription snapshot;
+
+  private final Path workingDir;
+
+  private final String tableName;
+
+  private final OperationAttemptTimer timer;
+  private final SnapshotExceptionSnare monitor;
+
+  private final MasterSnapshotVerifier verify;
+
+  /**
+   * @param snapshot descriptor of the snapshot to take
+   * @param server parent server
+   * @param masterServices master services provider
+   * @throws IOException on unexpected error
+   */
+  public DisabledTableSnapshotHandler(SnapshotDescription snapshot, Server server,
+      final MasterServices masterServices)
+      throws IOException {
+    super(server, EventType.C_M_SNAPSHOT_TABLE);
+    this.masterServices = masterServices;
+    this.tableName = snapshot.getTable();
+
+    this.snapshot = snapshot;
+    this.monitor = new SnapshotExceptionSnare(snapshot);
+
+    this.conf = this.masterServices.getConfiguration();
+    this.fs = this.masterServices.getMasterFileSystem().getFileSystem();
+
+    this.rootDir = FSUtils.getRootDir(this.conf);
+    this.workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
+
+    // prepare the verify
+    this.verify = new MasterSnapshotVerifier(masterServices, snapshot, rootDir);
+
+    // setup the timer
+    timer = TakeSnapshotUtils.getMasterTimerAndBindToMonitor(snapshot, conf, monitor);
+  }
+
+  // TODO consider parallelizing these operations since they are independent. Right now its just
+  // easier to keep them serial though
+  @Override
+  public void process() {
+    LOG.info("Running table snapshot operation " + eventType + " on table " + tableName);
+    try {
+      timer.start();
+      // write down the snapshot info in the working directory
+      SnapshotDescriptionUtils.writeSnapshotInfo(snapshot, workingDir, this.fs);
+
+      // 1. get all the regions hosting this table.
+      List<Pair<HRegionInfo, ServerName>> regionsAndLocations = null;
+      while (regionsAndLocations == null) {
+        try {
+          regionsAndLocations = MetaReader.getTableRegionsAndLocations(
+            this.server.getCatalogTracker(), Bytes.toBytes(tableName), true);
+        } catch (InterruptedException e) {
+          // check to see if we failed, in which case return
+          if (this.monitor.checkForError()) return;
+          // otherwise, just reset the interrupt and keep on going
+          Thread.currentThread().interrupt();
+        }
+      }
+
+      // extract each pair to separate lists
+      Set<String> serverNames = new HashSet<String>();
+      Set<HRegionInfo> regions = new HashSet<HRegionInfo>();
+      for (Pair<HRegionInfo, ServerName> p : regionsAndLocations) {
+        regions.add(p.getFirst());
+        serverNames.add(p.getSecond().toString());
+      }
+
+      // 2. for each region, write all the info to disk
+      LOG.info("Starting to write region info and WALs for regions for offline snapshot:"
+          + snapshot);
+      for (HRegionInfo regionInfo : regions) {
+        // 2.1 copy the regionInfo files to the snapshot
+        Path snapshotRegionDir = TakeSnapshotUtils.getRegionSnapshotDirectory(snapshot, rootDir,
+          regionInfo.getEncodedName());
+        HRegion.writeRegioninfoOnFilesystem(regionInfo, snapshotRegionDir, fs, conf);
+        // check for error for each region
+        monitor.failOnError();
+
+        // 2.2 for each region, copy over its recovered.edits directory
+        Path regionDir = HRegion.getRegionDir(rootDir, regionInfo);
+        new CopyRecoveredEditsTask(snapshot, monitor, fs, regionDir, snapshotRegionDir).run();
+        monitor.failOnError();
+
+        // 2.3 reference all the files in the region
+        new ReferenceRegionHFilesTask(snapshot, monitor, regionDir, fs, snapshotRegionDir).run();
+        monitor.failOnError();
+      }
+
+      // 3. write the table info to disk
+      LOG.info("Starting to copy tableinfo for offline snapshot:\n" + snapshot);
+      TableInfoCopyTask tableInfo = new TableInfoCopyTask(this.monitor, snapshot, fs,
+          FSUtils.getRootDir(conf));
+      tableInfo.run();
+      monitor.failOnError();
+
+      // 4. verify the snapshot is valid
+      verify.verifySnapshot(this.workingDir, serverNames);
+
+      // 5. complete the snapshot
+      SnapshotDescriptionUtils.completeSnapshot(this.snapshot, this.rootDir, this.workingDir,
+        this.fs);
+
+    } catch (Exception e) {
+      // make sure we capture the exception to propagate back to the client later
+      monitor.snapshotFailure("Failed due to exception:" + e.getMessage(), snapshot, e);
+    } finally {
+      LOG.debug("Marking snapshot" + this.snapshot + " as finished.");
+      this.stopped = true;
+
+      // 6. mark the timer as finished - even if we got an exception, we don't need to time the
+      // operation any further
+      timer.complete();
+
+      LOG.debug("Launching cleanup of working dir:" + workingDir);
+      try {
+        // don't mark the snapshot as a failure if we can't cleanup - the snapshot worked.
+        if (!this.fs.delete(this.workingDir, true)) {
+          LOG.error("Couldn't delete snapshot working directory:" + workingDir);
+        }
+      } catch (IOException e) {
+        LOG.error("Couldn't delete snapshot working directory:" + workingDir);
+      }
+    }
+  }
+
+  @Override
+  public boolean isFinished() {
+    return this.stopped;
+  }
+
+  @Override
+  public SnapshotDescription getSnapshot() {
+    return snapshot;
+  }
+
+  @Override
+  public void stop(String why) {
+    if (this.stopped) return;
+    this.stopped = true;
+    LOG.info("Stopping disabled snapshot because: " + why);
+    // pass along the stop as a failure. This keeps all the 'should I stop running?' logic in a
+    // single place, though it is technically a little bit of an overload of how the error handler
+    // should be used.
+    this.monitor.snapshotFailure("Failing snapshot because server is stopping.", snapshot);
+  }
+
+  @Override
+  public boolean isStopped() {
+    return this.stopped;
+  }
+
+  @Override
+  public HBaseSnapshotException getExceptionIfFailed() {
+    try {
+      this.monitor.failOnError();
+    } catch (HBaseSnapshotException e) {
+      return e;
+    }
+    return null;
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/MasterSnapshotVerifier.java

@@ -0,0 +1,252 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master.snapshot;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.PathFilter;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.catalog.MetaReader;
+import org.apache.hadoop.hbase.master.MasterServices;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Type;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.regionserver.StoreFile;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.CorruptedSnapshotException;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSTableDescriptors;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hbase.util.HFileArchiveUtil;
+
+/**
+ * General snapshot verification on the master.
+ * <p>
+ * This is a light-weight verification mechanism for all the files in a snapshot. It doesn't attempt
+ * to verify that the files are exact copies (that would be paramount to taking the snapshot
+ * again!), but instead just attempts to ensure that the files match the expected files and are the
+ * same length.
+ * <p>
+ * Current snapshot files checked:
+ * <ol>
+ * <li>SnapshotDescription is readable</li>
+ * <li>Table info is readable</li>
+ * <li>Regions</li>
+ * <ul>
+ * <li>Matching regions in the snapshot as currently in the table</li>
+ * <li>{@link HRegionInfo} matches the current and stored regions</li>
+ * <li>All referenced hfiles have valid names</li>
+ * <li>All the hfiles are present (either in .archive directory in the region)</li>
+ * <li>All recovered.edits files are present (by name) and have the correct file size</li>
+ * </ul>
+ * <li>HLogs for each server running the snapshot have been referenced
+ * <ul>
+ * <li>Only checked for {@link Type#GLOBAL} snapshots</li>
+ * </ul>
+ * </li>
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public final class MasterSnapshotVerifier {
+
+  private SnapshotDescription snapshot;
+  private FileSystem fs;
+  private Path rootDir;
+  private String tableName;
+  private MasterServices services;
+
+  /**
+   * Build a util for the given snapshot
+   * @param services services for the master
+   * @param snapshot snapshot to check
+   * @param rootDir root directory of the hbase installation.
+   */
+  public MasterSnapshotVerifier(MasterServices services, SnapshotDescription snapshot, Path rootDir) {
+    this.fs = services.getMasterFileSystem().getFileSystem();
+    this.services = services;
+    this.snapshot = snapshot;
+    this.rootDir = rootDir;
+    this.tableName = snapshot.getTable();
+  }
+
+  /**
+   * Verify that the snapshot in the directory is a valid snapshot
+   * @param snapshotDir snapshot directory to check
+   * @param snapshotServers {@link ServerName} of the servers that are involved in the snapshot
+   * @throws CorruptedSnapshotException if the snapshot is invalid
+   * @throws IOException if there is an unexpected connection issue to the filesystem
+   */
+  public void verifySnapshot(Path snapshotDir, Set<String> snapshotServers)
+      throws CorruptedSnapshotException, IOException {
+    // verify snapshot info matches
+    verifySnapshotDescription(snapshotDir);
+
+    // check that tableinfo is a valid table description
+    verifyTableInfo(snapshotDir);
+
+    // check that each region is valid
+    verifyRegions(snapshotDir);
+
+    // check that the hlogs, if they exist, are valid
+    if (shouldCheckLogs(snapshot.getType())) {
+      verifyLogs(snapshotDir, snapshotServers);
+    }
+  }
+
+  /**
+   * Check to see if the snapshot should verify the logs directory based on the type of the logs.
+   * @param type type of snapshot being taken
+   * @return <tt>true</tt> if the logs directory should be verified, <tt>false</tt> otherwise
+   */
+  private boolean shouldCheckLogs(Type type) {
+    // This is better handled in the Type enum via type, but since its PB based, this is the
+    // simplest way to handle it
+    return type.equals(Type.GLOBAL);
+  }
+
+  /**
+   * Check that the snapshot description written in the filesystem matches the current snapshot
+   * @param snapshotDir snapshot directory to check
+   */
+  private void verifySnapshotDescription(Path snapshotDir) throws CorruptedSnapshotException {
+    SnapshotDescription found = SnapshotDescriptionUtils.readSnapshotInfo(fs, snapshotDir);
+    if (!this.snapshot.equals(found)) {
+      throw new CorruptedSnapshotException("Snapshot read (" + found
+          + ") doesn't equal snapshot we ran (" + snapshot + ").", snapshot);
+    }
+  }
+
+  /**
+   * Check that the table descriptor for the snapshot is a valid table descriptor
+   * @param snapshotDir snapshot directory to check
+   */
+  private void verifyTableInfo(Path snapshotDir) throws IOException {
+    FSTableDescriptors.getTableDescriptor(fs, snapshotDir);
+  }
+
+  /**
+   * Check that all the regions in the the snapshot are valid
+   * @param snapshotDir snapshot directory to check
+   * @throws IOException if we can't reach .META. or read the files from the FS
+   */
+  private void verifyRegions(Path snapshotDir) throws IOException {
+    List<HRegionInfo> regions = MetaReader.getTableRegions(this.services.getCatalogTracker(),
+      Bytes.toBytes(tableName));
+    for (HRegionInfo region : regions) {
+      verifyRegion(fs, snapshotDir, region);
+    }
+  }
+
+  /**
+   * Verify that the region (regioninfo, hfiles) are valid
+   * @param snapshotDir snapshot directory to check
+   * @param region the region to check
+   */
+  private void verifyRegion(FileSystem fs, Path snapshotDir, HRegionInfo region) throws IOException {
+    // make sure we have region in the snapshot
+    Path regionDir = new Path(snapshotDir, region.getEncodedName());
+    if (!fs.exists(regionDir)) {
+      throw new CorruptedSnapshotException("No region directory found for region:" + region,
+          snapshot);
+    }
+    // make sure we have the region info in the snapshot
+    Path regionInfo = new Path(regionDir, HRegion.REGIONINFO_FILE);
+    // make sure the file exists
+    if (!fs.exists(regionInfo)) {
+      throw new CorruptedSnapshotException("No region info found for region:" + region, snapshot);
+    }
+    FSDataInputStream in = fs.open(regionInfo);
+    HRegionInfo found = HRegionInfo.parseFrom(in);
+    if (!region.equals(found)) {
+      throw new CorruptedSnapshotException("Found region info (" + found
+          + ") doesn't match expected region:" + region, snapshot);
+    }
+
+    // make sure we have the expected recovered edits files
+    TakeSnapshotUtils.verifyRecoveredEdits(fs, snapshotDir, found, snapshot);
+
+    // check for the existance of each hfile
+    PathFilter familiesDirs = new FSUtils.FamilyDirFilter(fs);
+    FileStatus[] columnFamilies = FSUtils.listStatus(fs, regionDir, familiesDirs);
+    // should we do some checking here to make sure the cfs are correct?
+    if (columnFamilies == null) return;
+
+    // setup the suffixes for the snapshot directories
+    Path tableNameSuffix = new Path(tableName);
+    Path regionNameSuffix = new Path(tableNameSuffix, region.getEncodedName());
+
+    // get the potential real paths
+    Path archivedRegion = new Path(HFileArchiveUtil.getArchivePath(services.getConfiguration()),
+        regionNameSuffix);
+    Path realRegion = new Path(rootDir, regionNameSuffix);
+
+    // loop through each cf and check we can find each of the hfiles
+    for (FileStatus cf : columnFamilies) {
+      FileStatus[] hfiles = FSUtils.listStatus(fs, cf.getPath(), null);
+      // should we check if there should be hfiles?
+      if (hfiles == null || hfiles.length == 0) continue;
+
+      Path realCfDir = new Path(realRegion, cf.getPath().getName());
+      Path archivedCfDir = new Path(archivedRegion, cf.getPath().getName());
+      for (FileStatus hfile : hfiles) {
+        // make sure the name is correct
+        if (!StoreFile.validateStoreFileName(hfile.getPath().getName())) {
+          throw new CorruptedSnapshotException("HFile: " + hfile.getPath()
+              + " is not a valid hfile name.", snapshot);
+        }
+
+        // check to see if hfile is present in the real table
+        String fileName = hfile.getPath().getName();
+        Path file = new Path(realCfDir, fileName);
+        Path archived = new Path(archivedCfDir, fileName);
+        if (!fs.exists(file) && !fs.equals(archived)) {
+          throw new CorruptedSnapshotException("Can't find hfile: " + hfile.getPath()
+              + " in the real (" + archivedCfDir + ") or archive (" + archivedCfDir
+              + ") directory for the primary table.", snapshot);
+        }
+      }
+    }
+  }
+
+  /**
+   * Check that the logs stored in the log directory for the snapshot are valid - it contains all
+   * the expected logs for all servers involved in the snapshot.
+   * @param snapshotDir snapshot directory to check
+   * @param snapshotServers list of the names of servers involved in the snapshot.
+   * @throws CorruptedSnapshotException if the hlogs in the snapshot are not correct
+   * @throws IOException if we can't reach the filesystem
+   */
+  private void verifyLogs(Path snapshotDir, Set<String> snapshotServers)
+      throws CorruptedSnapshotException, IOException {
+    Path snapshotLogDir = new Path(snapshotDir, HConstants.HREGION_LOGDIR_NAME);
+    Path logsDir = new Path(rootDir, HConstants.HREGION_LOGDIR_NAME);
+    TakeSnapshotUtils.verifyAllLogsGotReferenced(fs, logsDir, snapshotServers, snapshot,
+      snapshotLogDir);
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/master/snapshot/manage/SnapshotManager.java

@@ -0,0 +1,182 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master.snapshot.manage;
+
+import java.io.IOException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.Stoppable;
+import org.apache.hadoop.hbase.executor.ExecutorService;
+import org.apache.hadoop.hbase.master.MasterServices;
+import org.apache.hadoop.hbase.master.SnapshotSentinel;
+import org.apache.hadoop.hbase.master.snapshot.DisabledTableSnapshotHandler;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Type;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
+import org.apache.zookeeper.KeeperException;
+
+/**
+ * This class monitors the whole process of snapshots via ZooKeeper. There is only one
+ * SnapshotMonitor for the master.
+ * <p>
+ * Start monitoring a snapshot by calling method monitor() before the snapshot is started across the
+ * cluster via ZooKeeper. SnapshotMonitor would stop monitoring this snapshot only if it is finished
+ * or aborted.
+ * <p>
+ * Note: There could be only one snapshot being processed and monitored at a time over the cluster.
+ * Start monitoring a snapshot only when the previous one reaches an end status.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class SnapshotManager implements Stoppable {
+  private static final Log LOG = LogFactory.getLog(SnapshotManager.class);
+
+  // TODO - enable having multiple snapshots with multiple monitors
+
+  private final MasterServices master;
+  private SnapshotSentinel handler;
+  private ExecutorService pool;
+  private final Path rootDir;
+
+  private boolean stopped;
+
+  public SnapshotManager(final MasterServices master, final ZooKeeperWatcher watcher,
+      final ExecutorService executorService) throws KeeperException {
+    this.master = master;
+    this.pool = executorService;
+    this.rootDir = master.getMasterFileSystem().getRootDir();
+  }
+
+  /**
+   * @return <tt>true</tt> if there is a snapshot currently being taken, <tt>false</tt> otherwise
+   */
+  public boolean isTakingSnapshot() {
+    return handler != null && !handler.isFinished();
+  }
+
+  /**
+   * Check to make sure that we are OK to run the passed snapshot. Checks to make sure that we
+   * aren't already running a snapshot.
+   * @param snapshot description of the snapshot we want to start
+   * @throws HBaseSnapshotException if the filesystem could not be prepared to start the snapshot
+   */
+  private synchronized void prepareToTakeSnapshot(SnapshotDescription snapshot)
+      throws HBaseSnapshotException {
+    FileSystem fs = master.getMasterFileSystem().getFileSystem();
+    Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
+
+    // make sure we aren't already running a snapshot
+    if (isTakingSnapshot()) {
+      throw new SnapshotCreationException("Already running another snapshot:"
+          + this.handler.getSnapshot(), snapshot);
+    }
+
+    try {
+      // delete the working directory, since we aren't running the snapshot
+      fs.delete(workingDir, true);
+
+      // recreate the working directory for the snapshot
+      if (!fs.mkdirs(workingDir)) {
+        throw new SnapshotCreationException("Couldn't create working directory (" + workingDir
+            + ") for snapshot.", snapshot);
+      }
+    } catch (HBaseSnapshotException e) {
+      throw e;
+    } catch (IOException e) {
+      throw new SnapshotCreationException(
+          "Exception while checking to see if snapshot could be started.", e, snapshot);
+    }
+  }
+
+  /**
+   * Take a snapshot of a disabled table.
+   * <p>
+   * Ensures the snapshot won't be started if there is another snapshot already running. Does
+   * <b>not</b> check to see if another snapshot of the same name already exists.
+   * @param snapshot description of the snapshot to take. Modified to be {@link Type#DISABLED}.
+   * @throws HBaseSnapshotException if the snapshot could not be started
+   */
+  public synchronized void snapshotDisabledTable(SnapshotDescription snapshot)
+      throws HBaseSnapshotException {
+    // setup the snapshot
+    prepareToTakeSnapshot(snapshot);
+
+    // set the snapshot to be a disabled snapshot, since the client doesn't know about that
+    snapshot = snapshot.toBuilder().setType(Type.DISABLED).build();
+
+    DisabledTableSnapshotHandler handler;
+    try {
+      handler = new DisabledTableSnapshotHandler(snapshot, this.master, this.master);
+      this.handler = handler;
+      this.pool.submit(handler);
+    } catch (IOException e) {
+      // cleanup the working directory
+      Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
+      try {
+        if (this.master.getMasterFileSystem().getFileSystem().delete(workingDir, true)) {
+          LOG.error("Couldn't delete working directory (" + workingDir + " for snapshot:"
+              + snapshot);
+        }
+      } catch (IOException e1) {
+        LOG.error("Couldn't delete working directory (" + workingDir + " for snapshot:" + snapshot);
+      }
+      // fail the snapshot
+      throw new SnapshotCreationException("Could not build snapshot handler", e, snapshot);
+    }
+  }
+
+  /**
+   * @return the current handler for the snapshot
+   */
+  public SnapshotSentinel getCurrentSnapshotSentinel() {
+    return this.handler;
+  }
+
+  @Override
+  public void stop(String why) {
+    // short circuit
+    if (this.stopped) return;
+    // make sure we get stop
+    this.stopped = true;
+    // pass the stop onto all the listeners
+    if (this.handler != null) this.handler.stop(why);
+  }
+
+  @Override
+  public boolean isStopped() {
+    return this.stopped;
+  }
+
+  /**
+   * Set the handler for the current snapshot
+   * <p>
+   * Exposed for TESTING
+   * @param handler handler the master should use
+   */
+  public void setSnapshotHandlerForTesting(SnapshotSentinel handler) {
+    this.handler = handler;
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -781,27 +781,49 @@ public class HRegion implements HeapSize { // , Writable{
     return this.memstoreSize.getAndAdd(memStoreSize);
   }
 
-  /*
+  /**
-   * Write out an info file under the region directory.  Useful recovering
+   * Write out an info file under the stored region directory. Useful recovering mangled regions.
-   * mangled regions.
    * @throws IOException
    */
   private void checkRegioninfoOnFilesystem() throws IOException {
-    Path regioninfoPath = new Path(this.regiondir, REGIONINFO_FILE);
+    checkRegioninfoOnFilesystem(this.regiondir);
-    // Compose the content of the file so we can compare to length in filesystem.  If not same,
+  }
-    // rewrite it (it may have been written in the old format using Writables instead of pb).  The
+
+  /**
+   * Write out an info file under the region directory. Useful recovering mangled regions.
+   * @param regiondir directory under which to write out the region info
+   * @throws IOException
+   */
+  private void checkRegioninfoOnFilesystem(Path regiondir) throws IOException {
+    writeRegioninfoOnFilesystem(regionInfo, regiondir, getFilesystem(), conf);
+  }
+
+  /**
+   * Write out an info file under the region directory. Useful recovering mangled regions. If the
+   * regioninfo already exists on disk and there is information in the file, then we fast exit.
+   * @param regionInfo information about the region
+   * @param regiondir directory under which to write out the region info
+   * @param fs {@link FileSystem} on which to write the region info
+   * @param conf {@link Configuration} from which to extract specific file locations
+   * @throws IOException on unexpected error.
+   */
+  public static void writeRegioninfoOnFilesystem(HRegionInfo regionInfo, Path regiondir,
+      FileSystem fs, Configuration conf) throws IOException {
+    Path regioninfoPath = new Path(regiondir, REGIONINFO_FILE);
+    // Compose the content of the file so we can compare to length in filesystem. If not same,
+    // rewrite it (it may have been written in the old format using Writables instead of pb). The
     // pb version is much shorter -- we write now w/o the toString version -- so checking length
-    // only should be sufficient.  I don't want to read the file every time to check if it pb
+    // only should be sufficient. I don't want to read the file every time to check if it pb
     // serialized.
-    byte [] content = getDotRegionInfoFileContent(this.getRegionInfo());
+    byte[] content = getDotRegionInfoFileContent(regionInfo);
-    boolean exists = this.fs.exists(regioninfoPath);
+    boolean exists = fs.exists(regioninfoPath);
-    FileStatus status = exists? this.fs.getFileStatus(regioninfoPath): null;
+    FileStatus status = exists ? fs.getFileStatus(regioninfoPath) : null;
     if (status != null && status.getLen() == content.length) {
       // Then assume the content good and move on.
       return;
     }
     // Create in tmpdir and then move into place in case we crash after
-    // create but before close.  If we don't successfully close the file,
+    // create but before close. If we don't successfully close the file,
     // subsequent region reopens will fail the below because create is
     // registered in NN.
 
@@ -809,7 +831,7 @@ public class HRegion implements HeapSize { // , Writable{
     FsPermission perms = FSUtils.getFilePermissions(fs, conf, HConstants.DATA_FILE_UMASK_KEY);
 
     // And then create the file
-    Path tmpPath = new Path(getTmpDir(), REGIONINFO_FILE);
+    Path tmpPath = new Path(getTmpDir(regiondir), REGIONINFO_FILE);
 
     // If datanode crashes or if the RS goes down just before the close is called while trying to
     // close the created regioninfo file in the .tmp directory then on next
@@ -1251,7 +1273,11 @@ public class HRegion implements HeapSize { // , Writable{
    * will have its contents removed when the region is reopened.
    */
   Path getTmpDir() {
-    return new Path(getRegionDir(), REGION_TEMP_SUBDIR);
+    return getTmpDir(getRegionDir());
+  }
+
+  static Path getTmpDir(Path regionDir) {
+    return new Path(regionDir, REGION_TEMP_SUBDIR);
   }
 
   void triggerMajorCompaction() {

hbase-server/src/main/java/org/apache/hadoop/hbase/server/errorhandling/impl/ExceptionOrchestrator.java

@@ -59,7 +59,7 @@ public class ExceptionOrchestrator<E extends Exception> implements ExceptionList
       .create();
 
   /** Error visitor for framework listeners */
-  final ForwardingErrorVisitor genericVisitor = new ForwardingErrorVisitor();
+  public final ForwardingErrorVisitor genericVisitor = new ForwardingErrorVisitor();
 
   public ExceptionOrchestrator() {
     this("generic-error-dispatcher");

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/TakeSnapshotUtils.java

@@ -0,0 +1,325 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.PathFilter;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.regionserver.HStore;
+import org.apache.hadoop.hbase.regionserver.wal.HLogUtil;
+import org.apache.hadoop.hbase.server.errorhandling.ExceptionListener;
+import org.apache.hadoop.hbase.server.errorhandling.OperationAttemptTimer;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.CorruptedSnapshotException;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSUtils;
+
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimap;
+
+/**
+ * Utilities for useful when taking a snapshot
+ */
+public class TakeSnapshotUtils {
+
+  private static final Log LOG = LogFactory.getLog(TakeSnapshotUtils.class);
+
+  private TakeSnapshotUtils() {
+    // private constructor for util class
+  }
+
+  /**
+   * Get the per-region snapshot description location.
+   * <p>
+   * Under the per-snapshot directory, specific files per-region are kept in a similar layout as per
+   * the current directory layout.
+   * @param desc description of the snapshot
+   * @param rootDir root directory for the hbase installation
+   * @param regionName encoded name of the region (see {@link HRegionInfo#encodeRegionName(byte[])})
+   * @return path to the per-region directory for the snapshot
+   */
+  public static Path getRegionSnapshotDirectory(SnapshotDescription desc, Path rootDir,
+      String regionName) {
+    Path snapshotDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(desc, rootDir);
+    return HRegion.getRegionDir(snapshotDir, regionName);
+  }
+
+  /**
+   * Get the home directory for store-level snapshot files.
+   * <p>
+   * Specific files per store are kept in a similar layout as per the current directory layout.
+   * @param regionDir snapshot directory for the parent region, <b>not</b> the standard region
+   *          directory. See {@link #getRegionSnapshotDirectory(SnapshotDescription, Path, String)}
+   * @param family name of the store to snapshot
+   * @return path to the snapshot home directory for the store/family
+   */
+  public static Path getStoreSnapshotDirectory(Path regionDir, String family) {
+    return HStore.getStoreHomedir(regionDir, Bytes.toBytes(family));
+  }
+
+  /**
+   * Get the snapshot directory for each family to be added to the the snapshot
+   * @param snapshot description of the snapshot being take
+   * @param snapshotRegionDir directory in the snapshot where the region directory information
+   *          should be stored
+   * @param families families to be added (can be null)
+   * @return paths to the snapshot directory for each family, in the same order as the families
+   *         passed in
+   */
+  public static List<Path> getFamilySnapshotDirectories(SnapshotDescription snapshot,
+      Path snapshotRegionDir, FileStatus[] families) {
+    if (families == null || families.length == 0) return Collections.emptyList();
+
+    List<Path> familyDirs = new ArrayList<Path>(families.length);
+    for (FileStatus family : families) {
+      // build the reference directory name
+      familyDirs.add(getStoreSnapshotDirectory(snapshotRegionDir, family.getPath().getName()));
+    }
+    return familyDirs;
+  }
+
+  /**
+   * Create a snapshot timer for the master which notifies the monitor when an error occurs
+   * @param snapshot snapshot to monitor
+   * @param conf configuration to use when getting the max snapshot life
+   * @param monitor monitor to notify when the snapshot life expires
+   * @return the timer to use update to signal the start and end of the snapshot
+   */
+  @SuppressWarnings("rawtypes")
+  public static OperationAttemptTimer getMasterTimerAndBindToMonitor(SnapshotDescription snapshot,
+      Configuration conf, ExceptionListener monitor) {
+    long maxTime = SnapshotDescriptionUtils.getMaxMasterTimeout(conf, snapshot.getType(),
+      SnapshotDescriptionUtils.DEFAULT_MAX_WAIT_TIME);
+    return new OperationAttemptTimer(monitor, maxTime, snapshot);
+  }
+
+  /**
+   * Verify that all the expected logs got referenced
+   * @param fs filesystem where the logs live
+   * @param logsDir original logs directory
+   * @param serverNames names of the servers that involved in the snapshot
+   * @param snapshot description of the snapshot being taken
+   * @param snapshotLogDir directory for logs in the snapshot
+   * @throws IOException
+   */
+  public static void verifyAllLogsGotReferenced(FileSystem fs, Path logsDir,
+      Set<String> serverNames, SnapshotDescription snapshot, Path snapshotLogDir)
+      throws IOException {
+    assertTrue(snapshot, "Logs directory doesn't exist in snapshot", fs.exists(logsDir));
+    // for each of the server log dirs, make sure it matches the main directory
+    Multimap<String, String> snapshotLogs = getMapOfServersAndLogs(fs, snapshotLogDir, serverNames);
+    Multimap<String, String> realLogs = getMapOfServersAndLogs(fs, logsDir, serverNames);
+    if (realLogs != null) {
+      assertNotNull(snapshot, "No server logs added to snapshot", snapshotLogs);
+    } else if (realLogs == null) {
+      assertNull(snapshot, "Snapshotted server logs that don't exist", snapshotLogs);
+    }
+
+    // check the number of servers
+    Set<Entry<String, Collection<String>>> serverEntries = realLogs.asMap().entrySet();
+    Set<Entry<String, Collection<String>>> snapshotEntries = snapshotLogs.asMap().entrySet();
+    assertEquals(snapshot, "Not the same number of snapshot and original server logs directories",
+      serverEntries.size(), snapshotEntries.size());
+
+    // verify we snapshotted each of the log files
+    for (Entry<String, Collection<String>> serverLogs : serverEntries) {
+      // if the server is not the snapshot, skip checking its logs
+      if (!serverNames.contains(serverLogs.getKey())) continue;
+      Collection<String> snapshotServerLogs = snapshotLogs.get(serverLogs.getKey());
+      assertNotNull(snapshot, "Snapshots missing logs for server:" + serverLogs.getKey(),
+        snapshotServerLogs);
+
+      // check each of the log files
+      assertEquals(snapshot,
+        "Didn't reference all the log files for server:" + serverLogs.getKey(), serverLogs
+            .getValue().size(), snapshotServerLogs.size());
+      for (String log : serverLogs.getValue()) {
+        assertTrue(snapshot, "Snapshot logs didn't include " + log,
+          snapshotServerLogs.contains(log));
+      }
+    }
+  }
+
+  /**
+   * Verify one of a snapshot's region's recovered.edits, has been at the surface (file names,
+   * length), match the original directory.
+   * @param fs filesystem on which the snapshot had been taken
+   * @param rootDir full path to the root hbase directory
+   * @param regionInfo info for the region
+   * @param snapshot description of the snapshot that was taken
+   * @throws IOException if there is an unexpected error talking to the filesystem
+   */
+  public static void verifyRecoveredEdits(FileSystem fs, Path rootDir, HRegionInfo regionInfo,
+      SnapshotDescription snapshot) throws IOException {
+    Path regionDir = HRegion.getRegionDir(rootDir, regionInfo);
+    Path editsDir = HLogUtil.getRegionDirRecoveredEditsDir(regionDir);
+    Path snapshotRegionDir = TakeSnapshotUtils.getRegionSnapshotDirectory(snapshot, rootDir,
+      regionInfo.getEncodedName());
+    Path snapshotEditsDir = HLogUtil.getRegionDirRecoveredEditsDir(snapshotRegionDir);
+
+    FileStatus[] edits = FSUtils.listStatus(fs, editsDir);
+    FileStatus[] snapshotEdits = FSUtils.listStatus(fs, snapshotEditsDir);
+    if (edits == null) {
+      assertNull(snapshot, "Snapshot has edits but table doesn't", snapshotEdits);
+      return;
+    }
+
+    assertNotNull(snapshot, "Table has edits, but snapshot doesn't", snapshotEdits);
+
+    // check each of the files
+    assertEquals(snapshot, "Not same number of edits in snapshot as table", edits.length,
+      snapshotEdits.length);
+
+    // make sure we have a file with the same name as the original
+    // it would be really expensive to verify the content matches the original
+    for (FileStatus edit : edits) {
+      for (FileStatus sEdit : snapshotEdits) {
+        if (sEdit.getPath().equals(edit.getPath())) {
+          assertEquals(snapshot, "Snapshot file" + sEdit.getPath()
+              + " length not equal to the original: " + edit.getPath(), edit.getLen(),
+            sEdit.getLen());
+          break;
+        }
+      }
+      assertTrue(snapshot, "No edit in snapshot with name:" + edit.getPath(), false);
+    }
+  }
+
+  private static void assertNull(SnapshotDescription snapshot, String msg, Object isNull)
+      throws CorruptedSnapshotException {
+    if (isNull != null) {
+      throw new CorruptedSnapshotException(msg + ", Expected " + isNull + " to be null.", snapshot);
+    }
+  }
+
+  private static void assertNotNull(SnapshotDescription snapshot, String msg, Object notNull)
+      throws CorruptedSnapshotException {
+    if (notNull == null) {
+      throw new CorruptedSnapshotException(msg + ", Expected object to not be null, but was null.",
+          snapshot);
+    }
+  }
+
+  private static void assertTrue(SnapshotDescription snapshot, String msg, boolean isTrue)
+      throws CorruptedSnapshotException {
+    if (!isTrue) {
+      throw new CorruptedSnapshotException(msg + ", Expected true, but was false", snapshot);
+    }
+  }
+
+  /**
+   * Assert that the expect matches the gotten amount
+   * @param msg message to add the to exception
+   * @param expected
+   * @param gotten
+   * @throws CorruptedSnapshotException thrown if the two elements don't match
+   */
+  private static void assertEquals(SnapshotDescription snapshot, String msg, int expected,
+      int gotten) throws CorruptedSnapshotException {
+    if (expected != gotten) {
+      throw new CorruptedSnapshotException(msg + ". Expected:" + expected + ", got:" + gotten,
+          snapshot);
+    }
+  }
+
+  /**
+   * Assert that the expect matches the gotten amount
+   * @param msg message to add the to exception
+   * @param expected
+   * @param gotten
+   * @throws CorruptedSnapshotException thrown if the two elements don't match
+   */
+  private static void assertEquals(SnapshotDescription snapshot, String msg, long expected,
+      long gotten) throws CorruptedSnapshotException {
+    if (expected != gotten) {
+      throw new CorruptedSnapshotException(msg + ". Expected:" + expected + ", got:" + gotten,
+          snapshot);
+    }
+  }
+
+  /**
+   * @param logdir
+   * @param toInclude list of servers to include. If empty or null, returns all servers
+   * @return maps of servers to all their log files. If there is no log directory, returns
+   *         <tt>null</tt>
+   */
+  private static Multimap<String, String> getMapOfServersAndLogs(FileSystem fs, Path logdir,
+      Collection<String> toInclude) throws IOException {
+    // create a path filter based on the passed directories to include
+    PathFilter filter = toInclude == null || toInclude.size() == 0 ? null
+        : new MatchesDirectoryNames(toInclude);
+
+    // get all the expected directories
+    FileStatus[] serverLogDirs = FSUtils.listStatus(fs, logdir, filter);
+    if (serverLogDirs == null) return null;
+
+    // map those into a multimap of servername -> [log files]
+    Multimap<String, String> map = HashMultimap.create();
+    for (FileStatus server : serverLogDirs) {
+      FileStatus[] serverLogs = FSUtils.listStatus(fs, server.getPath(), null);
+      if (serverLogs == null) continue;
+      for (FileStatus log : serverLogs) {
+        map.put(server.getPath().getName(), log.getPath().getName());
+      }
+    }
+    return map;
+  }
+
+  /**
+   * Path filter that only accepts paths where that have a {@link Path#getName()} that is contained
+   * in the specified collection.
+   */
+  private static class MatchesDirectoryNames implements PathFilter {
+
+    Collection<String> paths;
+
+    public MatchesDirectoryNames(Collection<String> dirNames) {
+      this.paths = dirNames;
+    }
+
+    @Override
+    public boolean accept(Path path) {
+      return paths.contains(path.getName());
+    }
+  }
+
+  /**
+   * Get the log directory for a specific snapshot
+   * @param snapshotDir directory where the specific snapshot will be store
+   * @param serverName name of the parent regionserver for the log files
+   * @return path to the log home directory for the archive files.
+   */
+  public static Path getSnapshotHLogsDir(Path snapshotDir, String serverName) {
+    return new Path(snapshotDir, HLogUtil.getHLogDirectoryName(serverName));
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/error/SnapshotExceptionSnare.java

@@ -0,0 +1,71 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.error;
+
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.errorhandling.impl.ExceptionSnare;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.UnexpectedSnapshotException;
+
+/**
+ * {@link ExceptionSnare} for snapshot exceptions, ensuring that only the first exception is
+ * retained and always returned via {@link #failOnError()}.
+ * <p>
+ * Ensures that any generic exceptions received via
+ * {@link #receiveError(String, HBaseSnapshotException, Object...)} are in fact propagated as
+ * {@link HBaseSnapshotException}.
+ */
+public class SnapshotExceptionSnare extends ExceptionSnare<HBaseSnapshotException> implements
+    SnapshotFailureListener {
+
+  private SnapshotDescription snapshot;
+
+  /**
+   * Create a snare that expects errors for the passed snapshot. Any untyped exceptions passed to
+   * {@link #receiveError(String, HBaseSnapshotException, Object...)} are wrapped as an
+   * {@link UnexpectedSnapshotException} with the passed {@link SnapshotDescription}.
+   * @param snapshot
+   */
+  public SnapshotExceptionSnare(SnapshotDescription snapshot) {
+    this.snapshot = snapshot;
+  }
+
+  @Override
+  public void snapshotFailure(String reason, SnapshotDescription snapshot) {
+    this.receiveError(reason, null, snapshot);
+  }
+
+  @Override
+  public void snapshotFailure(String reason, SnapshotDescription snapshot, Exception t) {
+    this.receiveError(reason,
+      t instanceof HBaseSnapshotException ? (HBaseSnapshotException) t
+          : new UnexpectedSnapshotException(reason, t, snapshot), snapshot);
+  }
+
+  @Override
+  public void failOnError() throws HBaseSnapshotException {
+    try {
+      super.failOnError();
+    } catch (Exception e) {
+      if (e instanceof HBaseSnapshotException) {
+        throw (HBaseSnapshotException) e;
+      }
+      throw new UnexpectedSnapshotException(e.getMessage(), e, snapshot);
+    }
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/error/SnapshotFailureListener.java

@@ -0,0 +1,41 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.error;
+
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+
+/**
+ * Generic running snapshot failure listener
+ */
+public interface SnapshotFailureListener {
+
+  /**
+   * Notification that a given snapshot failed because of an error on the local server
+   * @param snapshot snapshot that failed
+   * @param reason explanation of why the snapshot failed
+   */
+  public void snapshotFailure(String reason, SnapshotDescription snapshot);
+
+  /**
+   * Notification that a given snapshot failed because of an error on the local server
+   * @param reason reason the snapshot failed
+   * @param snapshot the snapshot that failed
+   * @param t the exception that caused the failure
+   */
+  public void snapshotFailure(String reason, SnapshotDescription snapshot, Exception t);
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/task/CopyRecoveredEditsTask.java

@@ -0,0 +1,89 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import java.io.IOException;
+import java.util.NavigableSet;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.FileUtil;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.regionserver.wal.HLogUtil;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+
+/**
+ * Copy over each of the files in a region's recovered.edits directory to the region's snapshot
+ * directory.
+ * <p>
+ * This is a serial operation over each of the files in the recovered.edits directory and also
+ * streams all the bytes to the client and then back to the filesystem, so the files being copied
+ * should be <b>small</b> or it will (a) suck up a lot of bandwidth, and (b) take a long time.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public class CopyRecoveredEditsTask extends SnapshotTask {
+
+  private static final Log LOG = LogFactory.getLog(CopyRecoveredEditsTask.class);
+  private final FileSystem fs;
+  private final Path regiondir;
+  private final Path outputDir;
+
+  /**
+   * @param snapshot Snapshot being taken
+   * @param monitor error monitor for the snapshot
+   * @param fs {@link FileSystem} where the snapshot is being taken
+   * @param regionDir directory for the region to examine for edits
+   * @param snapshotRegionDir directory for the region in the snapshot
+   */
+  public CopyRecoveredEditsTask(SnapshotDescription snapshot, SnapshotExceptionSnare monitor,
+      FileSystem fs, Path regionDir, Path snapshotRegionDir) {
+    super(snapshot, monitor, "Copy recovered.edits for region:" + regionDir.getName());
+    this.fs = fs;
+    this.regiondir = regionDir;
+    this.outputDir = HLogUtil.getRegionDirRecoveredEditsDir(snapshotRegionDir);
+  }
+
+  @Override
+  public void process() throws IOException {
+    NavigableSet<Path> files = HLogUtil.getSplitEditFilesSorted(this.fs, regiondir);
+    if (files == null || files.size() == 0) return;
+
+    // copy over each file.
+    // this is really inefficient (could be trivially parallelized), but is
+    // really simple to reason about.
+    for (Path source : files) {
+      // check to see if the file is zero length, in which case we can skip it
+      FileStatus stat = fs.getFileStatus(source);
+      if (stat.getLen() <= 0) continue;
+
+      // its not zero length, so copy over the file
+      Path out = new Path(outputDir, source.getName());
+      LOG.debug("Copying " + source + " to " + out);
+      FileUtil.copy(fs, source, fs, out, true, fs.getConf());
+
+      // check for errors to the running operation after each file
+      this.failOnError();
+    }
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/task/ReferenceRegionHFilesTask.java

@@ -0,0 +1,126 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.PathFilter;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.util.FSUtils;
+
+/**
+ * Reference all the hfiles in a region for a snapshot.
+ * <p>
+ * Doesn't take into acccount if the hfiles are valid or not, just keeps track of what's in the
+ * region's directory.
+ */
+public class ReferenceRegionHFilesTask extends SnapshotTask {
+
+  public static final Log LOG = LogFactory.getLog(ReferenceRegionHFilesTask.class);
+  private final Path regiondir;
+  private final FileSystem fs;
+  private final PathFilter fileFilter;
+  private final Path snapshotDir;
+
+  /**
+   * Reference all the files in the given region directory
+   * @param snapshot snapshot for which to add references
+   * @param monitor to check/send error
+   * @param regionDir region directory to look for errors
+   * @param fs {@link FileSystem} where the snapshot/region live
+   * @param regionSnapshotDir directory in the snapshot to store region files
+   */
+  public ReferenceRegionHFilesTask(final SnapshotDescription snapshot,
+      SnapshotExceptionSnare monitor, Path regionDir, final FileSystem fs, Path regionSnapshotDir) {
+    super(snapshot, monitor, "Reference hfiles for region:" + regionDir.getName());
+    this.regiondir = regionDir;
+    this.fs = fs;
+
+    this.fileFilter = new PathFilter() {
+      @Override
+      public boolean accept(Path path) {
+        try {
+          return fs.isFile(path);
+        } catch (IOException e) {
+          LOG.error("Failed to reach fs to check file:" + path + ", marking as not file");
+          ReferenceRegionHFilesTask.this.snapshotFailure("Failed to reach fs to check file status",
+            e);
+          return false;
+        }
+      }
+    };
+    this.snapshotDir = regionSnapshotDir;
+  }
+
+  @Override
+  public void process() throws IOException {
+    FileStatus[] families = FSUtils.listStatus(fs, regiondir, new FSUtils.FamilyDirFilter(fs));
+
+    // if no families, then we are done again
+    if (families == null || families.length == 0) {
+      LOG.info("No families under region directory:" + regiondir
+          + ", not attempting to add references.");
+      return;
+    }
+
+    // snapshot directories to store the hfile reference
+    List<Path> snapshotFamilyDirs = TakeSnapshotUtils.getFamilySnapshotDirectories(snapshot,
+      snapshotDir, families);
+
+    LOG.debug("Add hfile references to snapshot directories:" + snapshotFamilyDirs);
+    for (int i = 0; i < families.length; i++) {
+      FileStatus family = families[i];
+      Path familyDir = family.getPath();
+      // get all the hfiles in the family
+      FileStatus[] hfiles = FSUtils.listStatus(fs, familyDir, fileFilter);
+
+      // if no hfiles, then we are done with this family
+      if (hfiles == null || hfiles.length == 0) {
+        LOG.debug("Not hfiles found for family: " + familyDir + ", skipping.");
+        continue;
+      }
+
+      // make the snapshot's family directory
+      Path snapshotFamilyDir = snapshotFamilyDirs.get(i);
+      fs.mkdirs(snapshotFamilyDir);
+
+      // create a reference for each hfile
+      for (FileStatus hfile : hfiles) {
+        Path referenceFile = new Path(snapshotFamilyDir, hfile.getPath().getName());
+        LOG.debug("Creating reference for:" + hfile.getPath() + " at " + referenceFile);
+        if (!fs.createNewFile(referenceFile)) {
+          throw new IOException("Failed to create reference file:" + referenceFile);
+        }
+      }
+    }
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Finished referencing hfiles, current region state:");
+      FSUtils.logFileSystemState(fs, regiondir, LOG);
+      LOG.debug("and the snapshot directory:");
+      FSUtils.logFileSystemState(fs, snapshotDir, LOG);
+    }
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/task/ReferenceServerWALsTask.java

@@ -0,0 +1,103 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.util.FSUtils;
+
+/**
+ * Reference all the WAL files under a server's WAL directory
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public class ReferenceServerWALsTask extends SnapshotTask {
+  private static final Log LOG = LogFactory.getLog(ReferenceServerWALsTask.class);
+  // XXX does this need to be HasThread?
+  private final FileSystem fs;
+  private final Configuration conf;
+  private final String serverName;
+  private Path logDir;
+
+  /**
+   * @param snapshot snapshot being run
+   * @param failureListener listener to check for errors while running the operation and to
+   *          propagate errors found while running the task
+   * @param logDir log directory for the server. Name of the directory is taken as the name of the
+   *          server
+   * @param conf {@link Configuration} to extract fileystem information
+   * @param fs filesystem where the log files are stored and should be referenced
+   * @throws IOException
+   */
+  public ReferenceServerWALsTask(SnapshotDescription snapshot,
+      SnapshotExceptionSnare failureListener, final Path logDir, final Configuration conf,
+      final FileSystem fs) throws IOException {
+    super(snapshot, failureListener, "Reference WALs for server:" + logDir.getName());
+    this.fs = fs;
+    this.conf = conf;
+    this.serverName = logDir.getName();
+    this.logDir = logDir;
+  }
+
+  @Override
+  public void process() throws IOException {
+    // TODO switch to using a single file to reference all required WAL files
+    // Iterate through each of the log files and add a reference to it.
+    // assumes that all the files under the server's logs directory is a log
+    FileStatus[] serverLogs = FSUtils.listStatus(fs, logDir, null);
+    if (serverLogs == null) LOG.info("No logs for server directory:" + logDir
+        + ", done referencing files.");
+
+    if (LOG.isDebugEnabled()) LOG.debug("Adding references for WAL files:"
+        + Arrays.toString(serverLogs));
+
+    for (FileStatus file : serverLogs) {
+      this.failOnError();
+
+      // TODO - switch to using MonitoredTask
+      // add the reference to the file
+      // 0. Build a reference path based on the file name
+      // get the current snapshot directory
+      Path rootDir = FSUtils.getRootDir(conf);
+      Path snapshotDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(this.snapshot, rootDir);
+      Path snapshotLogDir = TakeSnapshotUtils.getSnapshotHLogsDir(snapshotDir, serverName);
+      // actually store the reference on disk (small file)
+      Path ref = new Path(snapshotLogDir, file.getPath().getName());
+      if (!fs.createNewFile(ref)) {
+        if (!fs.exists(ref)) {
+          throw new IOException("Couldn't create reference for:" + file.getPath());
+        }
+      }
+      LOG.debug("Completed WAL referencing for: " + file.getPath() + " to " + ref);
+    }
+    LOG.debug("Successfully completed WAL referencing for ALL files");
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/task/SnapshotTask.java

@@ -0,0 +1,81 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.errorhandling.ExceptionCheckable;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+
+/**
+ * General snapshot operation taken on a regionserver
+ */
+public abstract class SnapshotTask implements ExceptionCheckable<HBaseSnapshotException>, Runnable {
+
+  private static final Log LOG = LogFactory.getLog(SnapshotTask.class);
+
+  private final SnapshotExceptionSnare errorMonitor;
+  private final String desc;
+
+  protected final SnapshotDescription snapshot;
+
+  /**
+   * @param snapshot Description of the snapshot we are going to operate on
+   * @param monitor listener interested in failures to the snapshot caused by this operation
+   * @param description description of the task being run, for logging
+   */
+  public SnapshotTask(SnapshotDescription snapshot, SnapshotExceptionSnare monitor,
+      String description) {
+    this.snapshot = snapshot;
+    this.errorMonitor = monitor;
+    this.desc = description;
+  }
+
+  protected final void snapshotFailure(String message, Exception e) {
+    this.errorMonitor.snapshotFailure(message, this.snapshot, e);
+  }
+
+  @Override
+  public void failOnError() throws HBaseSnapshotException {
+    this.errorMonitor.failOnError();
+  }
+
+  @Override
+  public boolean checkForError() {
+    return this.errorMonitor.checkForError();
+  }
+
+  @Override
+  public void run() {
+    try {
+      LOG.debug("Running: " + desc);
+      this.process();
+    } catch (Exception e) {
+      this.snapshotFailure("Failed to run " + this.desc, e);
+    }
+  }
+
+  /**
+   * Run the task for the snapshot.
+   * @throws Exception if the task fails. Will be propagated to any other tasks watching the same
+   *           {@link SnapshotErrorListener}.
+   */
+  protected abstract void process() throws Exception;
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/server/snapshot/task/TableInfoCopyTask.java

@@ -0,0 +1,75 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import java.io.IOException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSTableDescriptors;
+
+/**
+ * Copy the table info into the snapshot directory
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public class TableInfoCopyTask extends SnapshotTask {
+
+  public static final Log LOG = LogFactory.getLog(TableInfoCopyTask.class);
+  private final FileSystem fs;
+  private final Path rootDir;
+
+  /**
+   * Copy the table info for the given table into the snapshot
+   * @param failureListener listen for errors while running the snapshot
+   * @param snapshot snapshot for which we are copying the table info
+   * @param fs {@link FileSystem} where the tableinfo is stored (and where the copy will be written)
+   * @param rootDir root of the {@link FileSystem} where the tableinfo is stored
+   */
+  public TableInfoCopyTask(SnapshotExceptionSnare failureListener, SnapshotDescription snapshot,
+      FileSystem fs, Path rootDir) {
+    super(snapshot, failureListener, "Copy table info for table: " + snapshot.getTable());
+    this.rootDir = rootDir;
+    this.fs = fs;
+  }
+
+  @Override
+  public void process() throws IOException {
+    LOG.debug("Running table info copy.");
+    this.failOnError();
+    LOG.debug("Attempting to copy table info for snapshot:" + this.snapshot);
+    // get the HTable descriptor
+    HTableDescriptor orig = FSTableDescriptors.getTableDescriptor(fs, rootDir,
+      Bytes.toBytes(this.snapshot.getTable()));
+
+    this.failOnError();
+    // write a copy of descriptor to the snapshot directory
+    Path snapshotDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, rootDir);
+    FSTableDescriptors.createTableDescriptorForTableDirectory(fs, snapshotDir, orig, false);
+    LOG.debug("Finished copying tableinfo.");
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/SnapshotDescriptionUtils.java

@@ -17,19 +17,128 @@
  */
 package org.apache.hadoop.hbase.snapshot;
 
+import java.io.IOException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.snapshot.exception.CorruptedSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
+import org.apache.hadoop.hbase.util.FSUtils;
 
 /**
  * Utility class to help manage {@link SnapshotDescription SnapshotDesriptions}.
+ * <p>
+ * Snapshots are laid out on disk like this:
+ * 
+ * <pre>
+ * /hbase/.snapshots
+ *          /.tmp                <---- working directory
+ *          /[snapshot name]     <----- completed snapshot
+ * </pre>
+ * 
+ * A completed snapshot named 'completed' then looks like (multiple regions, servers, files, etc.
+ * signified by '...' on the same directory depth).
+ * 
+ * <pre>
+ * /hbase/.snapshots/completed
+ *                   .snapshotinfo          <--- Description of the snapshot
+ *                   .tableinfo             <--- Copy of the tableinfo
+ *                    /.logs
+ *                        /[server_name]
+ *                            /... [log files]
+ *                         ...
+ *                   /[region name]           <---- All the region's information
+ *                   .regioninfo              <---- Copy of the HRegionInfo
+ *                      /[column family name]
+ *                          /[hfile name]     <--- name of the hfile in the real region
+ *                          ...
+ *                      ...
+ *                    ...
+ * </pre>
+ * 
+ * Utility methods in this class are useful for getting the correct locations for different parts of
+ * the snapshot, as well as moving completed snapshots into place (see
+ * {@link #completeSnapshot(SnapshotDescription, Path, Path, FileSystem)}, and writing the
+ * {@link SnapshotDescription} to the working snapshot directory.
  */
 public class SnapshotDescriptionUtils {
 
+  /**
+   * Filter that only accepts completed snapshot directories
+   */
+  public static class CompletedSnaphotDirectoriesFilter extends FSUtils.DirFilter {
+
+    /**
+     * @param fs
+     */
+    public CompletedSnaphotDirectoriesFilter(FileSystem fs) {
+      super(fs);
+    }
+
+    @Override
+    public boolean accept(Path path) {
+      // only accept directories that aren't the tmp directory
+      if (super.accept(path)) {
+        return !path.getName().equals(SNAPSHOT_TMP_DIR_NAME);
+      }
+      return false;
+    }
+
+  }
+
+  private static final Log LOG = LogFactory.getLog(SnapshotDescriptionUtils.class);
+  /**
+   * Version of the fs layout for a snapshot. Future snapshots may have different file layouts,
+   * which we may need to read in differently.
+   */
+  public static final int SNAPSHOT_LAYOUT_VERSION = 0;
+
+  // snapshot directory constants
+  /**
+   * The file contains the snapshot basic information and it is under the directory of a snapshot.
+   */
+  public static final String SNAPSHOTINFO_FILE = ".snapshotinfo";
+
+  private static final String SNAPSHOT_TMP_DIR_NAME = ".tmp";
+  // snapshot operation values
+  /** Default value if no start time is specified */
+  public static final long NO_SNAPSHOT_START_TIME_SPECIFIED = 0;
+
+  public static final String MASTER_WAIT_TIME_GLOBAL_SNAPSHOT = "hbase.snapshot.global.master.timeout";
+  public static final String REGION_WAIT_TIME_GLOBAL_SNAPSHOT = "hbase.snapshot.global.region.timeout";
+  public static final String MASTER_WAIT_TIME_TIMESTAMP_SNAPSHOT = "hbase.snapshot.timestamp.master.timeout";
+  public static final String REGION_WAIT_TIME_TIMESTAMP_SNAPSHOT = "hbase.snapshot.timestamp.region.timeout";
+  public static final String MASTER_WAIT_TIME_DISABLED_SNAPSHOT = "hbase.snapshot.disabled.master.timeout";
+
+  /** Default timeout of 60 sec for a snapshot timeout on a region */
+  public static final long DEFAULT_REGION_SNAPSHOT_TIMEOUT = 60000;
+
+  /** By default, wait 60 seconds for a snapshot to complete */
+  public static final long DEFAULT_MAX_WAIT_TIME = 60000;
+
+  /**
+   * Conf key for amount of time the in the future a timestamp snapshot should be taken (ms).
+   * Defaults to {@value SnapshotDescriptionUtils#DEFAULT_TIMESTAMP_SNAPSHOT_SPLIT_IN_FUTURE}
+   */
+  public static final String TIMESTAMP_SNAPSHOT_SPLIT_POINT_ADDITION = "hbase.snapshot.timestamp.master.splittime";
+  /** Start 2 seconds in the future, if no start time given */
+  public static final long DEFAULT_TIMESTAMP_SNAPSHOT_SPLIT_IN_FUTURE = 2000;
+
   private SnapshotDescriptionUtils() {
     // private constructor for utility class
   }
-  
+
   /**
    * Check to make sure that the description of the snapshot requested is valid
    * @param snapshot description of the snapshot
@@ -44,4 +153,219 @@ public class SnapshotDescriptionUtils {
     // make sure the table name is valid
     HTableDescriptor.isLegalTableName(Bytes.toBytes(snapshot.getTable()));
   }
+
+  /**
+   * @param conf {@link Configuration} from which to check for the timeout
+   * @param type type of snapshot being taken
+   * @param defaultMaxWaitTime Default amount of time to wait, if none is in the configuration
+   * @return the max amount of time the master should wait for a snapshot to complete
+   */
+  public static long getMaxMasterTimeout(Configuration conf, SnapshotDescription.Type type,
+      long defaultMaxWaitTime) {
+    String confKey;
+    switch (type) {
+    case GLOBAL:
+      confKey = MASTER_WAIT_TIME_GLOBAL_SNAPSHOT;
+      break;
+    case TIMESTAMP:
+
+      confKey = MASTER_WAIT_TIME_TIMESTAMP_SNAPSHOT;
+    case DISABLED:
+    default:
+      confKey = MASTER_WAIT_TIME_DISABLED_SNAPSHOT;
+    }
+    return conf.getLong(confKey, defaultMaxWaitTime);
+  }
+
+  /**
+   * @param conf {@link Configuration} from which to check for the timeout
+   * @param type type of snapshot being taken
+   * @param defaultMaxWaitTime Default amount of time to wait, if none is in the configuration
+   * @return the max amount of time the region should wait for a snapshot to complete
+   */
+  public static long getMaxRegionTimeout(Configuration conf, SnapshotDescription.Type type,
+      long defaultMaxWaitTime) {
+    String confKey;
+    switch (type) {
+    case GLOBAL:
+      confKey = REGION_WAIT_TIME_GLOBAL_SNAPSHOT;
+      break;
+    case TIMESTAMP:
+    default:
+      confKey = REGION_WAIT_TIME_TIMESTAMP_SNAPSHOT;
+    }
+    return conf.getLong(confKey, defaultMaxWaitTime);
+  }
+
+  /**
+   * Get the snapshot root directory. All the snapshots are kept under this directory, i.e.
+   * ${hbase.rootdir}/.snapshot
+   * @param rootDir hbase root directory
+   * @return the base directory in which all snapshots are kept
+   */
+  public static Path getSnapshotRootDir(final Path rootDir) {
+    return new Path(rootDir, HConstants.SNAPSHOT_DIR_NAME);
+  }
+
+  /**
+   * Get the directory for a specified snapshot. This directory is a sub-directory of snapshot root
+   * directory and all the data files for a snapshot are kept under this directory.
+   * @param snapshot snapshot being taken
+   * @param rootDir hbase root directory
+   * @return the final directory for the completed snapshot
+   */
+  public static Path getCompletedSnapshotDir(final SnapshotDescription snapshot, final Path rootDir) {
+    return getCompletedSnapshotDir(snapshot.getName(), rootDir);
+  }
+
+  /**
+   * Get the directory for a completed snapshot. This directory is a sub-directory of snapshot root
+   * directory and all the data files for a snapshot are kept under this directory.
+   * @param snapshotName name of the snapshot being taken
+   * @param rootDir hbase root directory
+   * @return the final directory for the completed snapshot
+   */
+  public static Path getCompletedSnapshotDir(final String snapshotName, final Path rootDir) {
+    return getCompletedSnapshotDir(getSnapshotsDir(rootDir), snapshotName);
+  }
+
+  /**
+   * Get the directory to build a snapshot, before it is finalized
+   * @param snapshot snapshot that will be built
+   * @param rootDir root directory of the hbase installation
+   * @return {@link Path} where one can build a snapshot
+   */
+  public static Path getWorkingSnapshotDir(SnapshotDescription snapshot, final Path rootDir) {
+    return getCompletedSnapshotDir(new Path(getSnapshotsDir(rootDir), SNAPSHOT_TMP_DIR_NAME),
+      snapshot.getName());
+  }
+
+  /**
+   * Get the directory to store the snapshot instance
+   * @param snapshotsDir hbase-global directory for storing all snapshots
+   * @param snapshotName name of the snapshot to take
+   * @return
+   */
+  private static final Path getCompletedSnapshotDir(final Path snapshotsDir, String snapshotName) {
+    return new Path(snapshotsDir, snapshotName);
+  }
+
+  /**
+   * @param rootDir hbase root directory
+   * @return the directory for all completed snapshots;
+   */
+  public static final Path getSnapshotsDir(Path rootDir) {
+    return new Path(rootDir, HConstants.SNAPSHOT_DIR_NAME);
+  }
+
+  /**
+   * Convert the passed snapshot description into a 'full' snapshot description based on default
+   * parameters, if none have been supplied. This resolves any 'optional' parameters that aren't
+   * supplied to their default values.
+   * @param snapshot general snapshot descriptor
+   * @param conf Configuration to read configured snapshot defaults if snapshot is not complete
+   * @return a valid snapshot description
+   * @throws IllegalArgumentException if the {@link SnapshotDescription} is not a complete
+   *           {@link SnapshotDescription}.
+   */
+  public static SnapshotDescription validate(SnapshotDescription snapshot, Configuration conf)
+      throws IllegalArgumentException {
+    if (!snapshot.hasTable()) {
+      throw new IllegalArgumentException(
+        "Descriptor doesn't apply to a table, so we can't build it.");
+    }
+
+    // set the creation time, if one hasn't been set
+    long time = snapshot.getCreationTime();
+    if (time == SnapshotDescriptionUtils.NO_SNAPSHOT_START_TIME_SPECIFIED) {
+      time = EnvironmentEdgeManager.currentTimeMillis();
+      if (snapshot.getType().equals(SnapshotDescription.Type.TIMESTAMP)) {
+        long increment = conf.getLong(
+          SnapshotDescriptionUtils.TIMESTAMP_SNAPSHOT_SPLIT_POINT_ADDITION,
+          SnapshotDescriptionUtils.DEFAULT_TIMESTAMP_SNAPSHOT_SPLIT_IN_FUTURE);
+        LOG.debug("Setting timestamp snasphot in future by " + increment + " ms.");
+        time += increment;
+      }
+      LOG.debug("Creation time not specified, setting to:" + time + " (current time:"
+          + EnvironmentEdgeManager.currentTimeMillis() + ").");
+      SnapshotDescription.Builder builder = snapshot.toBuilder();
+      builder.setCreationTime(time);
+      snapshot = builder.build();
+    }
+    return snapshot;
+  }
+
+  /**
+   * Write the snapshot description into the working directory of a snapshot
+   * @param snapshot description of the snapshot being taken
+   * @param workingDir working directory of the snapshot
+   * @param fs {@link FileSystem} on which the snapshot should be taken
+   * @throws IOException if we can't reach the filesystem and the file cannot be cleaned up on
+   *           failure
+   */
+  public static void writeSnapshotInfo(SnapshotDescription snapshot, Path workingDir, FileSystem fs)
+      throws IOException {
+    FsPermission perms = FSUtils.getFilePermissions(fs, fs.getConf(),
+      HConstants.DATA_FILE_UMASK_KEY);
+    Path snapshotInfo = new Path(workingDir, SnapshotDescriptionUtils.SNAPSHOTINFO_FILE);
+    try {
+      FSDataOutputStream out = FSUtils.create(fs, snapshotInfo, perms, true);
+      try {
+        snapshot.writeTo(out);
+      } finally {
+        out.close();
+      }
+    } catch (IOException e) {
+      // if we get an exception, try to remove the snapshot info
+      if (!fs.delete(snapshotInfo, false)) {
+        String msg = "Couldn't delete snapshot info file: " + snapshotInfo;
+        LOG.error(msg);
+        throw new IOException(msg);
+      }
+    }
+  }
+
+  /**
+   * Read in the {@link SnapshotDescription} stored for the snapshot in the passed directory
+   * @param fs filesystem where the snapshot was taken
+   * @param snapshotDir directory where the snapshot was stored
+   * @return the stored snapshot description
+   * @throws CorruptedSnapshotException if the snapshot cannot be read
+   */
+  public static SnapshotDescription readSnapshotInfo(FileSystem fs, Path snapshotDir)
+      throws CorruptedSnapshotException {
+    Path snapshotInfo = new Path(snapshotDir, SNAPSHOTINFO_FILE);
+    try {
+      FSDataInputStream in = null;
+      try {
+        in = fs.open(snapshotInfo);
+        return SnapshotDescription.parseFrom(in);
+      } finally {
+        if (in != null) in.close();
+      }
+    } catch (IOException e) {
+      throw new CorruptedSnapshotException("Couldn't read snapshot info from:" + snapshotInfo, e);
+    }
+  }
+
+  /**
+   * Move the finished snapshot to its final, publicly visible directory - this marks the snapshot
+   * as 'complete'.
+   * @param snapshot description of the snapshot being tabken
+   * @param rootdir root directory of the hbase installation
+   * @param workingDir directory where the in progress snapshot was built
+   * @param fs {@link FileSystem} where the snapshot was built
+   * @throws SnapshotCreationException if the snapshot could not be moved
+   * @throws IOException the filesystem could not be reached
+   */
+  public static void completeSnapshot(SnapshotDescription snapshot, Path rootdir, Path workingDir,
+      FileSystem fs) throws SnapshotCreationException, IOException {
+    Path finishedDir = getCompletedSnapshotDir(snapshot, rootdir);
+    LOG.debug("Snapshot is done, just moving the snapshot from " + workingDir + " to "
+        + finishedDir);
+    if (!fs.rename(workingDir, finishedDir)) {
+      throw new SnapshotCreationException("Failed to move working directory(" + workingDir
+          + ") to completed directory(" + finishedDir + ").", snapshot);
+    }
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/CorruptedSnapshotException.java

@@ -0,0 +1,49 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot.exception;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+
+
+/**
+ * Exception thrown when the found snapshot info from the filesystem is not valid
+ */
+@SuppressWarnings("serial")
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class CorruptedSnapshotException extends HBaseSnapshotException {
+
+  /**
+   * @param message message describing the exception
+   * @param e cause
+   */
+  public CorruptedSnapshotException(String message, Exception e) {
+    super(message, e);
+  }
+
+  /**
+   * Snapshot was corrupt for some reason
+   * @param message full description of the failure
+   * @param snapshot snapshot that was expected
+   */
+  public CorruptedSnapshotException(String message, SnapshotDescription snapshot) {
+    super(message, snapshot);
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/HBaseSnapshotException.java

@@ -15,46 +15,62 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.hbase.snapshot;
+package org.apache.hadoop.hbase.snapshot.exception;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hbase.HBaseIOException;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
 
 /**
- * General exception when a snapshot fails.
+ * General exception base class for when a snapshot fails
  */
 @SuppressWarnings("serial")
-public class HBaseSnapshotException extends HBaseIOException {
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public abstract class HBaseSnapshotException extends HBaseIOException {
 
   private SnapshotDescription description;
 
+  /**
+   * Some exception happened for a snapshot and don't even know the snapshot that it was about
+   * @param msg Full description of the failure
+   */
   public HBaseSnapshotException(String msg) {
     super(msg);
   }
 
-  public HBaseSnapshotException(String msg, Throwable cause) {
+  /**
-    super(msg, cause);
+   * Exception for the given snapshot that has no previous root cause
-  }
+   * @param msg reason why the snapshot failed
-
+   * @param desc description of the snapshot that is being failed
-  public HBaseSnapshotException(Throwable cause) {
+   */
-    super(cause);
-  }
-
   public HBaseSnapshotException(String msg, SnapshotDescription desc) {
     super(msg);
     this.description = desc;
   }
 
-  public HBaseSnapshotException(Throwable cause, SnapshotDescription desc) {
+  /**
-    super(cause);
+   * Exception for the given snapshot due to another exception
-    this.description = desc;
+   * @param msg reason why the snapshot failed
-  }
+   * @param cause root cause of the failure
-
+   * @param desc description of the snapshot that is being failed
+   */
   public HBaseSnapshotException(String msg, Throwable cause, SnapshotDescription desc) {
     super(msg, cause);
     this.description = desc;
   }
 
+  /**
+   * Exception when the description of the snapshot cannot be determined, due to some root other
+   * root cause
+   * @param message description of what caused the failure
+   * @param e root cause
+   */
+  public HBaseSnapshotException(String message, Exception e) {
+    super(message, e);
+  }
+
   public SnapshotDescription getSnapshotDescription() {
     return this.description;
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/SnapshotCreationException.java

@@ -15,7 +15,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.hbase.snapshot;
+package org.apache.hadoop.hbase.snapshot.exception;
 
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
 
@@ -25,27 +25,30 @@ import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescriptio
 @SuppressWarnings("serial")
 public class SnapshotCreationException extends HBaseSnapshotException {
 
-  public SnapshotCreationException(String msg, SnapshotDescription desc) {
+  /**
-    super(msg, desc);
+   * Used internally by the RPC engine to pass the exception back to the client.
-  }
+   * @param msg error message to pass back
-
+   */
-  public SnapshotCreationException(String msg, Throwable cause, SnapshotDescription desc) {
-    super(msg, cause, desc);
-  }
-
-  public SnapshotCreationException(String msg, Throwable cause) {
-    super(msg, cause);
-  }
-
   public SnapshotCreationException(String msg) {
     super(msg);
   }
 
-  public SnapshotCreationException(Throwable cause, SnapshotDescription desc) {
+  /**
-    super(cause, desc);
+   * Failure to create the specified snapshot
+   * @param msg reason why the snapshot couldn't be completed
+   * @param desc description of the snapshot attempted
+   */
+  public SnapshotCreationException(String msg, SnapshotDescription desc) {
+    super(msg, desc);
   }
 
-  public SnapshotCreationException(Throwable cause) {
+  /**
-    super(cause);
+   * Failure to create the specified snapshot due to an external cause
+   * @param msg reason why the snapshot couldn't be completed
+   * @param cause root cause of the failure
+   * @param desc description of the snapshot attempted
+   */
+  public SnapshotCreationException(String msg, Throwable cause, SnapshotDescription desc) {
+    super(msg, cause, desc);
   }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/SnapshotDoesNotExistException.java

@@ -0,0 +1,40 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot.exception;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+
+
+/**
+ * Thrown when the server is looking for a snapshot but can't find the snapshot on the filesystem
+ */
+@SuppressWarnings("serial")
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class SnapshotDoesNotExistException extends HBaseSnapshotException {
+
+  /**
+   * @param desc expected snapshot to find
+   */
+  public SnapshotDoesNotExistException(SnapshotDescription desc) {
+    super("Snapshot doesn't exist on the filesystem", desc);
+  }
+
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/SnapshotExistsException.java

@@ -0,0 +1,40 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot.exception;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+
+/**
+ * Thrown when a snapshot exists but should not
+ */
+@SuppressWarnings("serial")
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class SnapshotExistsException extends HBaseSnapshotException {
+
+  /**
+   * Failure due to the snapshot already existing
+   * @param msg full description of the failure
+   * @param desc snapshot that was attempted
+   */
+  public SnapshotExistsException(String msg, SnapshotDescription desc) {
+    super(msg, desc);
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/TablePartiallyOpenException.java

@@ -0,0 +1,51 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot.exception;
+
+import java.io.IOException;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hbase.util.Bytes;
+
+/**
+ * Thrown if a table should be online/offline but is partial open
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class TablePartiallyOpenException extends IOException {
+  private static final long serialVersionUID = 3571982660065058361L;
+
+  public TablePartiallyOpenException() {
+    super();
+  }
+
+  /**
+   * @param s message
+   */
+  public TablePartiallyOpenException(String s) {
+    super(s);
+  }
+
+  /**
+   * @param tableName Name of table that is partial open
+   */
+  public TablePartiallyOpenException(byte[] tableName) {
+    this(Bytes.toString(tableName));
+  }
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/UnexpectedSnapshotException.java

@@ -0,0 +1,42 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot.exception;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+
+/**
+ * General exception when an unexpected error occurs while running a snapshot.
+ */
+@SuppressWarnings("serial")
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class UnexpectedSnapshotException extends HBaseSnapshotException {
+
+  /**
+   * General exception for some cause
+   * @param msg reason why the snapshot couldn't be completed
+   * @param cause root cause of the failure
+   * @param snapshot description of the snapshot attempted
+   */
+  public UnexpectedSnapshotException(String msg, Exception cause, SnapshotDescription snapshot) {
+    super(msg, cause, snapshot);
+  }
+
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/snapshot/exception/UnknownSnapshotException.java

@@ -15,14 +15,23 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.hbase.snapshot;
+package org.apache.hadoop.hbase.snapshot.exception;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 
 /**
- * Exception thrown when we get a snapshot error about a snapshot we don't know or recognize.
+ * Exception thrown when we get a request for a snapshot we don't recognize.
  */
 @SuppressWarnings("serial")
-public class UnknownSnapshotException extends SnapshotCreationException {
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class UnknownSnapshotException extends HBaseSnapshotException {
 
+
+  /**
+   * @param msg full infomration about the failure
+   */
   public UnknownSnapshotException(String msg) {
     super(msg);
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java

@@ -607,7 +607,25 @@ public class FSTableDescriptors implements TableDescriptors {
   public static boolean createTableDescriptor(FileSystem fs, Path rootdir,
       HTableDescriptor htableDescriptor, boolean forceCreation)
   throws IOException {
-    FileStatus status = getTableInfoPath(fs, rootdir, htableDescriptor.getNameAsString());
+    Path tabledir = FSUtils.getTablePath(rootdir, htableDescriptor.getNameAsString());
+    return createTableDescriptorForTableDirectory(fs, tabledir, htableDescriptor, forceCreation);
+  }
+
+  /**
+   * Create a new HTableDescriptor in HDFS in the specified table directory. Happens when we create
+   * a new table or snapshot a table.
+   * @param fs filesystem where the descriptor should be written
+   * @param tabledir directory under which we should write the file
+   * @param htableDescriptor description of the table to write
+   * @param forceCreation if <tt>true</tt>,then even if previous table descriptor is present it will
+   *          be overwritten
+   * @return <tt>true</tt> if the we successfully created the file, <tt>false</tt> if the file
+   *         already exists and we weren't forcing the descriptor creation.
+   * @throws IOException if a filesystem error occurs
+   */
+  public static boolean createTableDescriptorForTableDirectory(FileSystem fs, Path tabledir,
+      HTableDescriptor htableDescriptor, boolean forceCreation) throws IOException {
+    FileStatus status = getTableInfoPath(fs, tabledir);
     if (status != null) {
       LOG.info("Current tableInfoPath = " + status.getPath());
       if (!forceCreation) {
@@ -617,8 +635,7 @@ public class FSTableDescriptors implements TableDescriptors {
         }
       }
     }
-    Path p = writeTableDescriptor(fs, htableDescriptor,
+    Path p = writeTableDescriptor(fs, htableDescriptor, tabledir, status);
-      FSUtils.getTablePath(rootdir, htableDescriptor.getNameAsString()), status);
     return p != null;
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestSnapshotFromAdmin.java

@@ -43,9 +43,9 @@ import com.google.protobuf.RpcController;
  * Test snapshot logic from the client
  */
 @Category(SmallTests.class)
-public class TestSnapshotsFromAdmin {
+public class TestSnapshotFromAdmin {
 
-  private static final Log LOG = LogFactory.getLog(TestSnapshotsFromAdmin.class);
+  private static final Log LOG = LogFactory.getLog(TestSnapshotFromAdmin.class);
 
   /**
    * Test that the logic for doing 'correct' back-off based on exponential increase and the max-time
@@ -80,7 +80,8 @@ public class TestSnapshotsFromAdmin {
     Mockito.when(mockConnection.getConfiguration()).thenReturn(conf);
     Mockito.when(mockConnection.getKeepAliveMasterAdmin()).thenReturn(mockMaster);
     // set the max wait time for the snapshot to complete
-    TakeSnapshotResponse response = TakeSnapshotResponse.newBuilder().setExpectedTime(maxWaitTime)
+    TakeSnapshotResponse response = TakeSnapshotResponse.newBuilder()
+        .setExpectedTimeout(maxWaitTime)
         .build();
     Mockito
         .when(
@@ -97,7 +98,7 @@ public class TestSnapshotsFromAdmin {
 
     // setup the admin and run the test
     HBaseAdmin admin = new HBaseAdmin(mockConnection);
-    String snapshot = "snasphot";
+    String snapshot = "snapshot";
     String table = "table";
     // get start time
     long start = System.currentTimeMillis();
@@ -105,15 +106,16 @@ public class TestSnapshotsFromAdmin {
     long finish = System.currentTimeMillis();
     long elapsed = (finish - start);
     assertTrue("Elapsed time:" + elapsed + " is more than expected max:" + time, elapsed <= time);
+    admin.close();
   }
 
   /**
    * Make sure that we validate the snapshot name and the table name before we pass anything across
    * the wire
-   * @throws IOException on failure
+   * @throws Exception on failure
    */
   @Test
-  public void testValidateSnapshotName() throws IOException {
+  public void testValidateSnapshotName() throws Exception {
     HConnectionManager.HConnectionImplementation mockConnection = Mockito
         .mock(HConnectionManager.HConnectionImplementation.class);
     Configuration conf = HBaseConfiguration.create();
@@ -130,6 +132,21 @@ public class TestSnapshotsFromAdmin {
     failSnapshotStart(admin, builder.setName("snapshot").setTable("-table").build());
     failSnapshotStart(admin, builder.setName("snapshot").setTable("table fails").build());
     failSnapshotStart(admin, builder.setName("snapshot").setTable("tab%le").build());
+
+    // mock the master connection
+    MasterAdminKeepAliveConnection master = Mockito.mock(MasterAdminKeepAliveConnection.class);
+    Mockito.when(mockConnection.getKeepAliveMasterAdmin()).thenReturn(master);
+    TakeSnapshotResponse response = TakeSnapshotResponse.newBuilder().setExpectedTimeout(0).build();
+    Mockito.when(
+      master.snapshot((RpcController) Mockito.isNull(), Mockito.any(TakeSnapshotRequest.class)))
+        .thenReturn(response);
+    IsSnapshotDoneResponse doneResponse = IsSnapshotDoneResponse.newBuilder().setDone(true).build();
+    Mockito.when(
+      master.isSnapshotDone((RpcController) Mockito.isNull(),
+        Mockito.any(IsSnapshotDoneRequest.class))).thenReturn(doneResponse);
+
+      // make sure that we can use valid names
+    admin.snapshot(builder.setName("snapshot").setTable("table").build());
   }
 
   private void failSnapshotStart(HBaseAdmin admin, SnapshotDescription snapshot) throws IOException {

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestSnapshotFromClient.java

@@ -0,0 +1,199 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.client;
+
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.LargeTests;
+import org.apache.hadoop.hbase.TableNotFoundException;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.snapshot.SnapshotTestingUtils;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+/**
+ * Test create/using/deleting snapshots from the client
+ * <p>
+ * This is an end-to-end test for the snapshot utility
+ */
+@Category(LargeTests.class)
+public class TestSnapshotFromClient {
+  private static final Log LOG = LogFactory.getLog(TestSnapshotFromClient.class);
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+  private static final int NUM_RS = 2;
+  private static final String STRING_TABLE_NAME = "test";
+  private static final byte[] TEST_FAM = Bytes.toBytes("fam");
+  private static final byte[] TABLE_NAME = Bytes.toBytes(STRING_TABLE_NAME);
+
+  /**
+   * Setup the config for the cluster
+   * @throws Exception on failure
+   */
+  @BeforeClass
+  public static void setupCluster() throws Exception {
+    setupConf(UTIL.getConfiguration());
+    UTIL.startMiniCluster(NUM_RS);
+  }
+
+  private static void setupConf(Configuration conf) {
+    // disable the ui
+    conf.setInt("hbase.regionsever.info.port", -1);
+    // change the flush size to a small amount, regulating number of store files
+    conf.setInt("hbase.hregion.memstore.flush.size", 25000);
+    // so make sure we get a compaction when doing a load, but keep around some
+    // files in the store
+    conf.setInt("hbase.hstore.compaction.min", 10);
+    conf.setInt("hbase.hstore.compactionThreshold", 10);
+    // block writes if we get to 12 store files
+    conf.setInt("hbase.hstore.blockingStoreFiles", 12);
+    // drop the number of attempts for the hbase admin
+    conf.setInt("hbase.client.retries.number", 1);
+  }
+
+  @Before
+  public void setup() throws Exception {
+    UTIL.createTable(TABLE_NAME, TEST_FAM);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    UTIL.deleteTable(TABLE_NAME);
+    // and cleanup the archive directory
+    try {
+      UTIL.getTestFileSystem().delete(new Path(UTIL.getDefaultRootDirPath(), ".archive"), true);
+    } catch (IOException e) {
+      LOG.warn("Failure to delete archive directory", e);
+    }
+  }
+
+  @AfterClass
+  public static void cleanupTest() throws Exception {
+    try {
+      UTIL.shutdownMiniCluster();
+    } catch (Exception e) {
+      LOG.warn("failure shutting down cluster", e);
+    }
+  }
+
+  /**
+   * Test snapshotting a table that is offline
+   * @throws Exception
+   */
+  @Test
+  public void testOfflineTableSnapshot() throws Exception {
+    HBaseAdmin admin = UTIL.getHBaseAdmin();
+    // make sure we don't fail on listing snapshots
+    SnapshotTestingUtils.assertNoSnapshots(admin);
+
+    // put some stuff in the table
+    HTable table = new HTable(UTIL.getConfiguration(), TABLE_NAME);
+    UTIL.loadTable(table, TEST_FAM);
+
+    // get the name of all the regionservers hosting the snapshotted table
+    Set<String> snapshotServers = new HashSet<String>();
+    List<RegionServerThread> servers = UTIL.getMiniHBaseCluster().getLiveRegionServerThreads();
+    for (RegionServerThread server : servers) {
+      if (server.getRegionServer().getOnlineRegions(TABLE_NAME).size() > 0) {
+        snapshotServers.add(server.getRegionServer().getServerName().toString());
+      }
+    }
+
+    LOG.debug("FS state before disable:");
+    FSUtils.logFileSystemState(UTIL.getTestFileSystem(),
+      FSUtils.getRootDir(UTIL.getConfiguration()), LOG);
+    // XXX if this is flakey, might want to consider using the async version and looping as
+    // disableTable can succeed and still timeout.
+    admin.disableTable(TABLE_NAME);
+
+    LOG.debug("FS state before snapshot:");
+    FSUtils.logFileSystemState(UTIL.getTestFileSystem(),
+      FSUtils.getRootDir(UTIL.getConfiguration()), LOG);
+
+    // take a snapshot of the disabled table
+    byte[] snapshot = Bytes.toBytes("offlineTableSnapshot");
+    admin.snapshot(snapshot, TABLE_NAME);
+    LOG.debug("Snapshot completed.");
+
+    // make sure we have the snapshot
+    List<SnapshotDescription> snapshots = SnapshotTestingUtils.assertOneSnapshotThatMatches(admin,
+      snapshot, TABLE_NAME);
+
+    // make sure its a valid snapshot
+    FileSystem fs = UTIL.getHBaseCluster().getMaster().getMasterFileSystem().getFileSystem();
+    Path rootDir = UTIL.getHBaseCluster().getMaster().getMasterFileSystem().getRootDir();
+    LOG.debug("FS state after snapshot:");
+    FSUtils.logFileSystemState(UTIL.getTestFileSystem(),
+      FSUtils.getRootDir(UTIL.getConfiguration()), LOG);
+
+    SnapshotTestingUtils.confirmSnapshotValid(snapshots.get(0), TABLE_NAME, TEST_FAM, rootDir,
+      admin, fs, false, new Path(rootDir, HConstants.HREGION_LOGDIR_NAME), snapshotServers);
+
+    admin.deleteSnapshot(snapshot);
+    snapshots = admin.listSnapshots();
+    SnapshotTestingUtils.assertNoSnapshots(admin);
+  }
+
+  @Test
+  public void testSnapshotFailsOnNonExistantTable() throws Exception {
+    HBaseAdmin admin = UTIL.getHBaseAdmin();
+    // make sure we don't fail on listing snapshots
+    SnapshotTestingUtils.assertNoSnapshots(admin);
+    String tableName = "_not_a_table";
+
+    // make sure the table doesn't exist
+    boolean fail = false;
+    do {
+    try {
+    admin.getTableDescriptor(Bytes.toBytes(tableName));
+    fail = true;
+        LOG.error("Table:" + tableName + " already exists, checking a new name");
+    tableName = tableName+"!";
+    }catch(TableNotFoundException e) {
+      fail = false;
+      }
+    } while (fail);
+
+    // snapshot the non-existant table
+    try {
+      admin.snapshot("fail", tableName);
+      fail("Snapshot succeeded even though there is not table.");
+    } catch (SnapshotCreationException e) {
+      LOG.info("Correctly failed to snapshot a non-existant table:" + e.getMessage());
+    }
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestSnapshotFromMaster.java

@@ -0,0 +1,248 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.MediumTests;
+import org.apache.hadoop.hbase.master.snapshot.DisabledTableSnapshotHandler;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.DeleteSnapshotRequest;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.IsSnapshotDoneRequest;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.IsSnapshotDoneResponse;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.ListSnapshotRequest;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.ListSnapshotResponse;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.SnapshotTestingUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.snapshot.exception.UnknownSnapshotException;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.mockito.Mockito;
+
+import com.google.common.collect.Lists;
+import com.google.protobuf.ServiceException;
+
+/**
+ * Test the master-related aspects of a snapshot
+ */
+@Category(MediumTests.class)
+public class TestSnapshotFromMaster {
+
+  private static final Log LOG = LogFactory.getLog(TestSnapshotFromMaster.class);
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+  private static final int NUM_RS = 2;
+  private static Path rootDir;
+  private static Path snapshots;
+  private static FileSystem fs;
+  private static HMaster master;
+
+  /**
+   * Setup the config for the cluster
+   */
+  @BeforeClass
+  public static void setupCluster() throws Exception {
+    setupConf(UTIL.getConfiguration());
+    UTIL.startMiniCluster(NUM_RS);
+    fs = UTIL.getDFSCluster().getFileSystem();
+    rootDir = FSUtils.getRootDir(UTIL.getConfiguration());
+    snapshots = SnapshotDescriptionUtils.getSnapshotsDir(rootDir);
+    master = UTIL.getMiniHBaseCluster().getMaster();
+  }
+
+  private static void setupConf(Configuration conf) {
+    // disable the ui
+    conf.setInt("hbase.regionsever.info.port", -1);
+    // change the flush size to a small amount, regulating number of store files
+    conf.setInt("hbase.hregion.memstore.flush.size", 25000);
+    // so make sure we get a compaction when doing a load, but keep around some
+    // files in the store
+    conf.setInt("hbase.hstore.compaction.min", 5);
+    conf.setInt("hbase.hstore.compactionThreshold", 5);
+    // block writes if we get to 12 store files
+    conf.setInt("hbase.hstore.blockingStoreFiles", 12);
+    // drop the number of attempts for the hbase admin
+    conf.setInt("hbase.client.retries.number", 1);
+  }
+
+  @Before
+  public void setup() throws Exception {
+    master.getSnapshotManagerForTesting().setSnapshotHandlerForTesting(null);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    if (!fs.delete(snapshots, true)) {
+      throw new IOException("Couldn't delete snapshots directory (" + snapshots
+          + " for an unknown reason");
+    }
+  }
+
+  @AfterClass
+  public static void cleanupTest() throws Exception {
+    try {
+      UTIL.shutdownMiniCluster();
+    } catch (Exception e) {
+      // NOOP;
+    }
+  }
+
+  /**
+   * Test that the contract from the master for checking on a snapshot are valid.
+   * <p>
+   * <ol>
+   * <li>If a snapshot fails with an error, we expect to get the source error.</li>
+   * <li>If there is no snapshot name supplied, we should get an error.</li>
+   * <li>If asking about a snapshot has hasn't occurred, you should get an error.</li>
+   * </ol>
+   */
+  @Test(timeout = 15000)
+  public void testIsDoneContract() throws Exception {
+
+    IsSnapshotDoneRequest.Builder builder = IsSnapshotDoneRequest.newBuilder();
+    String snapshotName = "asyncExpectedFailureTest";
+
+    // check that we get an exception when looking up snapshot where one hasn't happened
+    SnapshotTestingUtils.expectSnapshotDoneException(master, builder.build(),
+      UnknownSnapshotException.class);
+
+    // and that we get the same issue, even if we specify a name
+    SnapshotDescription desc = SnapshotDescription.newBuilder().setName(snapshotName).build();
+    builder.setSnapshot(desc);
+    SnapshotTestingUtils.expectSnapshotDoneException(master, builder.build(),
+      UnknownSnapshotException.class);
+
+    // set a mock handler to simulate a snapshot
+    DisabledTableSnapshotHandler mockHandler = Mockito.mock(DisabledTableSnapshotHandler.class);
+    Mockito.when(mockHandler.getExceptionIfFailed()).thenReturn(null);
+    Mockito.when(mockHandler.getSnapshot()).thenReturn(desc);
+    Mockito.when(mockHandler.isFinished()).thenReturn(new Boolean(true));
+
+    master.getSnapshotManagerForTesting().setSnapshotHandlerForTesting(mockHandler);
+
+    // if we do a lookup without a snapshot name, we should fail - you should always know your name
+    builder = IsSnapshotDoneRequest.newBuilder();
+    SnapshotTestingUtils.expectSnapshotDoneException(master, builder.build(),
+      UnknownSnapshotException.class);
+
+    // then do the lookup for the snapshot that it is done
+    builder.setSnapshot(desc);
+    IsSnapshotDoneResponse response = master.isSnapshotDone(null, builder.build());
+    assertTrue("Snapshot didn't complete when it should have.", response.getDone());
+
+    // now try the case where we are looking for a snapshot we didn't take
+    builder.setSnapshot(SnapshotDescription.newBuilder().setName("Not A Snapshot").build());
+    SnapshotTestingUtils.expectSnapshotDoneException(master, builder.build(),
+      UnknownSnapshotException.class);
+
+    // then create a snapshot to the fs and make sure that we can find it when checking done
+    snapshotName = "completed";
+    FileSystem fs = master.getMasterFileSystem().getFileSystem();
+    Path root = master.getMasterFileSystem().getRootDir();
+    Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, root);
+    desc = desc.toBuilder().setName(snapshotName).build();
+    SnapshotDescriptionUtils.writeSnapshotInfo(desc, snapshotDir, fs);
+
+    builder.setSnapshot(desc);
+    response = master.isSnapshotDone(null, builder.build());
+    assertTrue("Completed, on-disk snapshot not found", response.getDone());
+    
+    HBaseSnapshotException testException = new SnapshotCreationException("test fail", desc);
+    Mockito.when(mockHandler.getExceptionIfFailed()).thenReturn(testException);
+    try {
+      master.isSnapshotDone(null, builder.build());
+      fail("Master should have passed along snapshot error, but didn't");
+    }catch(ServiceException e) {
+      LOG.debug("Correctly got exception back from the master on failure: " + e.getMessage());
+    }
+  }
+
+  @Test
+  public void testListSnapshots() throws Exception {
+    // first check when there are no snapshots
+    ListSnapshotRequest request = ListSnapshotRequest.newBuilder().build();
+    ListSnapshotResponse response = master.listSnapshots(null, request);
+    assertEquals("Found unexpected number of snapshots", 0, response.getSnapshotsCount());
+
+    // write one snapshot to the fs
+    String snapshotName = "completed";
+    Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, rootDir);
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName(snapshotName).build();
+    SnapshotDescriptionUtils.writeSnapshotInfo(snapshot, snapshotDir, fs);
+
+    // check that we get one snapshot
+    response = master.listSnapshots(null, request);
+    assertEquals("Found unexpected number of snapshots", 1, response.getSnapshotsCount());
+    List<SnapshotDescription> snapshots = response.getSnapshotsList();
+    List<SnapshotDescription> expected = Lists.newArrayList(snapshot);
+    assertEquals("Returned snapshots don't match created snapshots", expected, snapshots);
+
+    // write a second snapshot
+    snapshotName = "completed_two";
+    snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, rootDir);
+    snapshot = SnapshotDescription.newBuilder().setName(snapshotName).build();
+    SnapshotDescriptionUtils.writeSnapshotInfo(snapshot, snapshotDir, fs);
+    expected.add(snapshot);
+
+    // check that we get one snapshot
+    response = master.listSnapshots(null, request);
+    assertEquals("Found unexpected number of snapshots", 2, response.getSnapshotsCount());
+    snapshots = response.getSnapshotsList();
+    assertEquals("Returned snapshots don't match created snapshots", expected, snapshots);
+  }
+
+  @Test
+  public void testDeleteSnapshot() throws Exception {
+
+    String snapshotName = "completed";
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName(snapshotName).build();
+
+    DeleteSnapshotRequest request = DeleteSnapshotRequest.newBuilder().setSnapshot(snapshot)
+        .build();
+    try {
+      master.deleteSnapshot(null, request);
+      fail("Master didn't throw exception when attempting to delete snapshot that doesn't exist");
+    } catch (ServiceException e) {
+      LOG.debug("Correctly failed delete of non-existant snapshot:" + e.getMessage());
+    }
+
+    // write one snapshot to the fs
+    Path snapshotDir = SnapshotDescriptionUtils.getCompletedSnapshotDir(snapshotName, rootDir);
+    SnapshotDescriptionUtils.writeSnapshotInfo(snapshot, snapshotDir, fs);
+
+    // then delete the existing snapshot,which shouldn't cause an exception to be thrown
+    master.deleteSnapshot(null, request);
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/master/snapshot/manage/TestSnapshotManager.java

@@ -0,0 +1,132 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master.snapshot.manage;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.SmallTests;
+import org.apache.hadoop.hbase.TableDescriptors;
+import org.apache.hadoop.hbase.executor.ExecutorService;
+import org.apache.hadoop.hbase.master.MasterFileSystem;
+import org.apache.hadoop.hbase.master.MasterServices;
+import org.apache.hadoop.hbase.master.SnapshotSentinel;
+import org.apache.hadoop.hbase.master.snapshot.DisabledTableSnapshotHandler;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.snapshot.exception.SnapshotCreationException;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
+import org.apache.zookeeper.KeeperException;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.mockito.Mockito;
+
+/**
+ * Test basic snapshot manager functionality
+ */
+@Category(SmallTests.class)
+public class TestSnapshotManager {
+  private static final Log LOG = LogFactory.getLog(TestSnapshotManager.class);
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  MasterServices services = Mockito.mock(MasterServices.class);
+  ZooKeeperWatcher watcher = Mockito.mock(ZooKeeperWatcher.class);
+  ExecutorService pool = Mockito.mock(ExecutorService.class);
+  MasterFileSystem mfs = Mockito.mock(MasterFileSystem.class);
+  FileSystem fs;
+  {
+    try {
+      fs = UTIL.getTestFileSystem();
+    } catch (IOException e) {
+      throw new RuntimeException("Couldn't get test filesystem", e);
+    }
+
+  }
+
+  private SnapshotManager getNewManager() throws KeeperException {
+    Mockito.reset(services, watcher, pool);
+    Mockito.when(services.getMasterFileSystem()).thenReturn(mfs);
+    Mockito.when(mfs.getFileSystem()).thenReturn(fs);
+    Mockito.when(mfs.getRootDir()).thenReturn(UTIL.getDataTestDir());
+    return new SnapshotManager(services, watcher, pool);
+  }
+
+
+
+  @Test
+  public void testInProcess() throws KeeperException, SnapshotCreationException {
+    SnapshotManager manager = getNewManager();
+    SnapshotSentinel handler = Mockito.mock(SnapshotSentinel.class);
+    assertFalse("Manager is in process when there is no current handler", manager.isTakingSnapshot());
+    manager.setSnapshotHandlerForTesting(handler);
+    Mockito.when(handler.isFinished()).thenReturn(false);
+    assertTrue("Manager isn't in process when handler is running", manager.isTakingSnapshot());
+    Mockito.when(handler.isFinished()).thenReturn(true);
+    assertFalse("Manager is process when handler isn't running", manager.isTakingSnapshot());
+  }
+
+  /**
+   * Test that we stop the running disabled table snapshot by passing along an error to the error
+   * handler.
+   * @throws Exception
+   */
+  @Test
+  public void testStopPropagation() throws Exception {
+    // create a new orchestrator and hook up a listener
+    SnapshotManager manager = getNewManager();
+    FSUtils.setRootDir(UTIL.getConfiguration(), UTIL.getDataTestDir());
+
+    // setup a mock snapshot to run
+    String tableName = "some table";
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("testAbort")
+        .setTable(tableName).build();
+    // mock out all the expected call to the master services
+    // this allows us to run must faster and without using a minicluster
+
+    // ensure the table exists when we ask for it
+    TableDescriptors tables = Mockito.mock(TableDescriptors.class);
+    Mockito.when(services.getTableDescriptors()).thenReturn(tables);
+    HTableDescriptor descriptor = Mockito.mock(HTableDescriptor.class);
+    Mockito.when(tables.get(Mockito.anyString())).thenReturn(descriptor);
+
+    // return the local file system as the backing to the MasterFileSystem
+    MasterFileSystem mfs = Mockito.mock(MasterFileSystem.class);
+    Mockito.when(mfs.getFileSystem()).thenReturn(UTIL.getTestFileSystem());
+    Mockito.when(services.getMasterFileSystem()).thenReturn(mfs);
+    Mockito.when(services.getConfiguration()).thenReturn(UTIL.getConfiguration());
+
+    // create a new handler that we will check for errors
+    manager.snapshotDisabledTable(snapshot);
+    // make sure we submitted the handler, but because its mocked, it doesn't run it.
+    Mockito.verify(pool, Mockito.times(1)).submit(Mockito.any(DisabledTableSnapshotHandler.class));
+
+    // pass along the stop notification
+    manager.stop("stopping for test");
+    SnapshotSentinel handler = manager.getCurrentSnapshotSentinel();
+    assertNotNull("Snare didn't receive error notification from snapshot manager.",
+      handler.getExceptionIfFailed());
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/server/snapshot/error/TestSnapshotExceptionSnare.java

@@ -0,0 +1,74 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.error;
+
+import static org.junit.Assert.fail;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.errorhandling.ExceptionListener;
+import org.apache.hadoop.hbase.server.errorhandling.OperationAttemptTimer;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.junit.Test;
+
+/**
+ * Test the exception snare propagates errors as expected
+ */
+public class TestSnapshotExceptionSnare {
+
+  private static final Log LOG = LogFactory.getLog(TestSnapshotExceptionSnare.class);
+
+  /**
+   * This test ensures that we only propagate snapshot exceptions, even if we don't get a snapshot
+   * exception
+   */
+  @Test
+  @SuppressWarnings({ "rawtypes", "unchecked" })
+  public void testPropagatesOnlySnapshotException() {
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("snapshot").build();
+    ExceptionListener snare = new SnapshotExceptionSnare(snapshot);
+    snare.receiveError("Some message", new Exception());
+    try {
+      ((SnapshotExceptionSnare) snare).failOnError();
+      fail("Snare didn't throw an exception");
+    } catch (HBaseSnapshotException e) {
+      LOG.error("Correctly got a snapshot exception" + e);
+    }
+  }
+
+  @Test
+  public void testPropatesTimerError() {
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("snapshot").build();
+    SnapshotExceptionSnare snare = new SnapshotExceptionSnare(snapshot);
+    Configuration conf = new Configuration();
+    // don't let the timer count down before we fire it off
+    conf.setLong(SnapshotDescriptionUtils.MASTER_WAIT_TIME_DISABLED_SNAPSHOT, Long.MAX_VALUE);
+    OperationAttemptTimer timer = TakeSnapshotUtils.getMasterTimerAndBindToMonitor(snapshot, conf,
+      snare);
+    timer.trigger();
+    try {
+      snare.failOnError();
+    } catch (HBaseSnapshotException e) {
+      LOG.info("Correctly failed from timer:" + e.getMessage());
+    }
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/server/snapshot/task/TestCopyRecoveredEditsTask.java

@@ -0,0 +1,128 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.SmallTests;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.regionserver.wal.HLogUtil;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.mockito.Mockito;
+
+/**
+ * Test that we correctly copy the recovered edits from a directory
+ */
+@Category(SmallTests.class)
+public class TestCopyRecoveredEditsTask {
+
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  @Test
+  public void testCopyFiles() throws Exception {
+
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("snapshot").build();
+    SnapshotExceptionSnare monitor = Mockito.mock(SnapshotExceptionSnare.class);
+    FileSystem fs = UTIL.getTestFileSystem();
+    Path root = UTIL.getDataTestDir();
+    String regionName = "regionA";
+    Path regionDir = new Path(root, regionName);
+    Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, root);
+
+    try {
+      // doesn't really matter where the region's snapshot directory is, but this is pretty close
+      Path snapshotRegionDir = new Path(workingDir, regionName);
+      fs.mkdirs(snapshotRegionDir);
+
+      // put some stuff in the recovered.edits directory
+      Path edits = HLogUtil.getRegionDirRecoveredEditsDir(regionDir);
+      fs.mkdirs(edits);
+      // make a file with some data
+      Path file1 = new Path(edits, "0000000000000002352");
+      FSDataOutputStream out = fs.create(file1);
+      byte[] data = new byte[] { 1, 2, 3, 4 };
+      out.write(data);
+      out.close();
+      // make an empty file
+      Path empty = new Path(edits, "empty");
+      fs.createNewFile(empty);
+
+      CopyRecoveredEditsTask task = new CopyRecoveredEditsTask(snapshot, monitor, fs, regionDir,
+          snapshotRegionDir);
+      task.run();
+
+      Path snapshotEdits = HLogUtil.getRegionDirRecoveredEditsDir(snapshotRegionDir);
+      FileStatus[] snapshotEditFiles = FSUtils.listStatus(fs, snapshotEdits);
+      assertEquals("Got wrong number of files in the snapshot edits", 1, snapshotEditFiles.length);
+      FileStatus file = snapshotEditFiles[0];
+      assertEquals("Didn't copy expected file", file1.getName(), file.getPath().getName());
+
+      Mockito.verify(monitor, Mockito.never()).receiveError(Mockito.anyString(),
+        Mockito.any(HBaseSnapshotException.class));
+      Mockito.verify(monitor, Mockito.never()).snapshotFailure(Mockito.anyString(),
+        Mockito.any(SnapshotDescription.class));
+      Mockito.verify(monitor, Mockito.never()).snapshotFailure(Mockito.anyString(),
+        Mockito.any(SnapshotDescription.class), Mockito.any(Exception.class));
+    } finally {
+      // cleanup the working directory
+      FSUtils.delete(fs, regionDir, true);
+      FSUtils.delete(fs, workingDir, true);
+    }
+  }
+
+  /**
+   * Check that we don't get an exception if there is no recovered edits directory to copy
+   * @throws Exception on failure
+   */
+  @Test
+  public void testNoEditsDir() throws Exception {
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("snapshot").build();
+    SnapshotExceptionSnare monitor = Mockito.mock(SnapshotExceptionSnare.class);
+    FileSystem fs = UTIL.getTestFileSystem();
+    Path root = UTIL.getDataTestDir();
+    String regionName = "regionA";
+    Path regionDir = new Path(root, regionName);
+    Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, root);
+    try {
+      // doesn't really matter where the region's snapshot directory is, but this is pretty close
+      Path snapshotRegionDir = new Path(workingDir, regionName);
+      fs.mkdirs(snapshotRegionDir);
+      Path regionEdits = HLogUtil.getRegionDirRecoveredEditsDir(regionDir);
+      assertFalse("Edits dir exists already - it shouldn't", fs.exists(regionEdits));
+
+      CopyRecoveredEditsTask task = new CopyRecoveredEditsTask(snapshot, monitor, fs, regionDir,
+          snapshotRegionDir);
+      task.run();
+    } finally {
+      // cleanup the working directory
+      FSUtils.delete(fs, regionDir, true);
+      FSUtils.delete(fs, workingDir, true);
+    }
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/server/snapshot/task/TestReferenceRegionHFilesTask.java

@@ -0,0 +1,92 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.SmallTests;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.mockito.Mockito;
+
+@Category(SmallTests.class)
+public class TestReferenceRegionHFilesTask {
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  @Test
+  public void testRun() throws IOException {
+    FileSystem fs = UTIL.getTestFileSystem();
+    // setup the region internals
+    Path testdir = UTIL.getDataTestDir();
+    Path regionDir = new Path(testdir, "region");
+    Path family1 = new Path(regionDir, "fam1");
+    // make an empty family
+    Path family2 = new Path(regionDir, "fam2");
+    fs.mkdirs(family2);
+
+    // add some files to family 1
+    Path file1 = new Path(family1, "05f99689ae254693836613d1884c6b63");
+    fs.createNewFile(file1);
+    Path file2 = new Path(family1, "7ac9898bf41d445aa0003e3d699d5d26");
+    fs.createNewFile(file2);
+
+    // create the snapshot directory
+    Path snapshotRegionDir = new Path(testdir, HConstants.SNAPSHOT_DIR_NAME);
+    fs.mkdirs(snapshotRegionDir);
+
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("name")
+        .setTable("table").build();
+    SnapshotExceptionSnare monitor = Mockito.mock(SnapshotExceptionSnare.class);
+    ReferenceRegionHFilesTask task = new ReferenceRegionHFilesTask(snapshot, monitor, regionDir,
+        fs, snapshotRegionDir);
+    task.run();
+
+    // make sure we never get an error
+    Mockito.verify(monitor, Mockito.never()).snapshotFailure(Mockito.anyString(),
+      Mockito.eq(snapshot));
+    Mockito.verify(monitor, Mockito.never()).snapshotFailure(Mockito.anyString(),
+      Mockito.eq(snapshot), Mockito.any(Exception.class));
+
+    // verify that all the hfiles get referenced
+    List<String> hfiles = new ArrayList<String>(2);
+    FileStatus[] regions = FSUtils.listStatus(fs, snapshotRegionDir);
+    for (FileStatus region : regions) {
+      FileStatus[] fams = FSUtils.listStatus(fs, region.getPath());
+      for (FileStatus fam : fams) {
+        FileStatus[] files = FSUtils.listStatus(fs, fam.getPath());
+        for (FileStatus file : files) {
+          hfiles.add(file.getPath().getName());
+        }
+      }
+    }
+    assertTrue("Didn't reference :" + file1, hfiles.contains(file1.getName()));
+    assertTrue("Didn't reference :" + file1, hfiles.contains(file2.getName()));
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/server/snapshot/task/TestSnapshotTask.java

@@ -0,0 +1,52 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import org.apache.hadoop.hbase.SmallTests;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+import org.mockito.Mockito;
+
+@Category(SmallTests.class)
+public class TestSnapshotTask {
+
+  /**
+   * Check that errors from running the task get propagated back to the error listener.
+   */
+  @Test
+  public void testErrorPropagationg() {
+    SnapshotExceptionSnare error = Mockito.mock(SnapshotExceptionSnare.class);
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("snapshot")
+        .setTable("table").build();
+    final Exception thrown = new Exception("Failed!");
+    SnapshotTask fail = new SnapshotTask(snapshot, error, "always fails") {
+
+      @Override
+      protected void process() throws Exception {
+        throw thrown;
+      }
+    };
+    fail.run();
+
+    Mockito.verify(error, Mockito.times(1)).snapshotFailure(Mockito.anyString(),
+      Mockito.eq(snapshot), Mockito.eq(thrown));
+  }
+
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/server/snapshot/task/TestWALReferenceTask.java

@@ -0,0 +1,99 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.server.snapshot.task;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.server.snapshot.error.SnapshotExceptionSnare;
+import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.junit.Test;
+import org.mockito.Mockito;
+
+/**
+ * Test that the WAL reference task works as expected
+ */
+public class TestWALReferenceTask {
+
+  private static final Log LOG = LogFactory.getLog(TestWALReferenceTask.class);
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  @Test
+  public void testRun() throws IOException {
+    Configuration conf = UTIL.getConfiguration();
+    FileSystem fs = UTIL.getTestFileSystem();
+    // setup the log dir
+    Path testDir = UTIL.getDataTestDir();
+    Set<String> servers = new HashSet<String>();
+    Path logDir = new Path(testDir, ".logs");
+    Path server1Dir = new Path(logDir, "Server1");
+    servers.add(server1Dir.getName());
+    Path server2Dir = new Path(logDir, "me.hbase.com,56073,1348618509968");
+    servers.add(server2Dir.getName());
+    // logs under server 1
+    Path log1_1 = new Path(server1Dir, "me.hbase.com%2C56073%2C1348618509968.1348618520536");
+    Path log1_2 = new Path(server1Dir, "me.hbase.com%2C56073%2C1348618509968.1234567890123");
+    // logs under server 2
+    Path log2_1 = new Path(server2Dir, "me.hbase.com%2C56074%2C1348618509998.1348618515589");
+    Path log2_2 = new Path(server2Dir, "me.hbase.com%2C56073%2C1348618509968.1234567890123");
+
+    // create all the log files
+    fs.createNewFile(log1_1);
+    fs.createNewFile(log1_2);
+    fs.createNewFile(log2_1);
+    fs.createNewFile(log2_2);
+
+    FSUtils.logFileSystemState(fs, testDir, LOG);
+    FSUtils.setRootDir(conf, testDir);
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder()
+        .setName("testWALReferenceSnapshot").build();
+    SnapshotExceptionSnare listener = Mockito.mock(SnapshotExceptionSnare.class);
+
+    // reference all the files in the first server directory
+    ReferenceServerWALsTask task = new ReferenceServerWALsTask(snapshot, listener, server1Dir,
+        conf, fs);
+    task.run();
+
+    // reference all the files in the first server directory
+    task = new ReferenceServerWALsTask(snapshot, listener, server2Dir, conf, fs);
+    task.run();
+
+    // verify that we got everything
+    FSUtils.logFileSystemState(fs, testDir, LOG);
+    Path workingDir = SnapshotDescriptionUtils.getWorkingSnapshotDir(snapshot, testDir);
+    Path snapshotLogDir = new Path(workingDir, HConstants.HREGION_LOGDIR_NAME);
+
+    // make sure we reference the all the wal files
+    TakeSnapshotUtils.verifyAllLogsGotReferenced(fs, logDir, servers, snapshot, snapshotLogDir);
+
+    // make sure we never got an error
+    Mockito.verify(listener, Mockito.atLeastOnce()).failOnError();
+    Mockito.verifyNoMoreInteractions(listener);
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/SnapshotTestingUtils.java

@@ -0,0 +1,188 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.client.HBaseAdmin;
+import org.apache.hadoop.hbase.master.HMaster;
+import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.IsSnapshotDoneRequest;
+import org.apache.hadoop.hbase.protobuf.generated.MasterAdminProtos.IsSnapshotDoneResponse;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.server.snapshot.TakeSnapshotUtils;
+import org.apache.hadoop.hbase.snapshot.exception.HBaseSnapshotException;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSTableDescriptors;
+import org.junit.Assert;
+
+import com.google.protobuf.ServiceException;
+
+/**
+ * Utilities class for snapshots
+ */
+public class SnapshotTestingUtils {
+
+  private static final Log LOG = LogFactory.getLog(SnapshotTestingUtils.class);
+
+  /**
+   * Assert that we don't have any snapshots lists
+   * @throws IOException if the admin operation fails
+   */
+  public static void assertNoSnapshots(HBaseAdmin admin) throws IOException {
+    assertEquals("Have some previous snapshots", 0, admin.listSnapshots().size());
+  }
+
+  /**
+   * Make sure that there is only one snapshot returned from the master and its name and table match
+   * the passed in parameters.
+   */
+  public static void assertOneSnapshotThatMatches(HBaseAdmin admin, SnapshotDescription snapshot)
+      throws IOException {
+    assertOneSnapshotThatMatches(admin, snapshot.getName(), snapshot.getTable());
+  }
+
+  /**
+   * Make sure that there is only one snapshot returned from the master and its name and table match
+   * the passed in parameters.
+   */
+  public static List<SnapshotDescription> assertOneSnapshotThatMatches(HBaseAdmin admin,
+      String snapshotName, String tableName) throws IOException {
+    // list the snapshot
+    List<SnapshotDescription> snapshots = admin.listSnapshots();
+
+    assertEquals("Should only have 1 snapshot", 1, snapshots.size());
+    assertEquals(snapshotName, snapshots.get(0).getName());
+    assertEquals(tableName, snapshots.get(0).getTable());
+
+    return snapshots;
+  }
+
+  /**
+   * Make sure that there is only one snapshot returned from the master and its name and table match
+   * the passed in parameters.
+   */
+  public static List<SnapshotDescription> assertOneSnapshotThatMatches(HBaseAdmin admin,
+      byte[] snapshot, byte[] tableName) throws IOException {
+    return assertOneSnapshotThatMatches(admin, Bytes.toString(snapshot), Bytes.toString(tableName));
+  }
+
+  /**
+   * Confirm that the snapshot contains references to all the files that should be in the snapshot
+   */
+  public static void confirmSnapshotValid(SnapshotDescription snapshotDescriptor, byte[] tableName,
+      byte[] testFamily, Path rootDir, HBaseAdmin admin, FileSystem fs, boolean requireLogs,
+      Path logsDir, Set<String> snapshotServers) throws IOException {
+    Path snapshotDir = SnapshotDescriptionUtils
+        .getCompletedSnapshotDir(snapshotDescriptor, rootDir);
+    assertTrue(fs.exists(snapshotDir));
+    Path snapshotinfo = new Path(snapshotDir, SnapshotDescriptionUtils.SNAPSHOTINFO_FILE);
+    assertTrue(fs.exists(snapshotinfo));
+    // check the logs dir
+    if (requireLogs) {
+      TakeSnapshotUtils.verifyAllLogsGotReferenced(fs, logsDir, snapshotServers,
+        snapshotDescriptor, new Path(snapshotDir, HConstants.HREGION_LOGDIR_NAME));
+    }
+    // check the table info
+    HTableDescriptor desc = FSTableDescriptors.getTableDescriptor(fs, rootDir, tableName);
+    HTableDescriptor snapshotDesc = FSTableDescriptors.getTableDescriptor(fs, snapshotDir);
+    assertEquals(desc, snapshotDesc);
+
+    // check the region snapshot for all the regions
+    List<HRegionInfo> regions = admin.getTableRegions(tableName);
+    for (HRegionInfo info : regions) {
+      String regionName = info.getEncodedName();
+      Path regionDir = new Path(snapshotDir, regionName);
+      HRegionInfo snapshotRegionInfo = HRegion.loadDotRegionInfoFileContent(fs, regionDir);
+      assertEquals(info, snapshotRegionInfo);
+      // check to make sure we have the family
+      Path familyDir = new Path(regionDir, Bytes.toString(testFamily));
+      assertTrue("Expected to find: " + familyDir + ", but it doesn't exist", fs.exists(familyDir));
+      // make sure we have some files references
+      assertTrue(fs.listStatus(familyDir).length > 0);
+    }
+  }
+
+  /**
+   * Helper method for testing async snapshot operations. Just waits for the given snapshot to
+   * complete on the server by repeatedly checking the master.
+   * @param master running the snapshot
+   * @param snapshot to check
+   * @param sleep amount to sleep between checks to see if the snapshot is done
+   * @throws ServiceException if the snapshot fails
+   */
+  public static void waitForSnapshotToComplete(HMaster master, SnapshotDescription snapshot,
+      long sleep) throws ServiceException {
+    final IsSnapshotDoneRequest request = IsSnapshotDoneRequest.newBuilder().setSnapshot(snapshot)
+        .build();
+    IsSnapshotDoneResponse done = IsSnapshotDoneResponse.newBuilder().buildPartial();
+    while (!done.getDone()) {
+      done = master.isSnapshotDone(null, request);
+      try {
+        Thread.sleep(sleep);
+      } catch (InterruptedException e) {
+        throw new ServiceException(e);
+      }
+    }
+  }
+
+  public static void cleanupSnapshot(HBaseAdmin admin, byte[] tableName) throws IOException {
+    SnapshotTestingUtils.cleanupSnapshot(admin, Bytes.toString(tableName));
+  }
+
+  public static void cleanupSnapshot(HBaseAdmin admin, String snapshotName) throws IOException {
+    // delete the taken snapshot
+    admin.deleteSnapshot(snapshotName);
+    assertNoSnapshots(admin);
+  }
+
+  /**
+   * Expect the snapshot to throw an error when checking if the snapshot is complete
+   * @param master master to check
+   * @param snapshot the {@link SnapshotDescription} request to pass to the master
+   * @param clazz expected exception from the master
+   */
+  public static void expectSnapshotDoneException(HMaster master, IsSnapshotDoneRequest snapshot,
+      Class<? extends HBaseSnapshotException> clazz) {
+    try {
+      master.isSnapshotDone(null, snapshot);
+      Assert.fail("didn't fail to lookup a snapshot");
+    } catch (ServiceException se) {
+      try {
+        throw ProtobufUtil.getRemoteException(se);
+      } catch (HBaseSnapshotException e) {
+        assertEquals("Threw wrong snapshot exception!", clazz, e.getClass());
+      } catch (Throwable t) {
+        Assert.fail("Threw an unexpected exception:" + t);
+      }
+    }
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/snapshot/TestSnapshotDescriptionUtils.java

@@ -0,0 +1,138 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.snapshot;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.SmallTests;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
+import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription.Type;
+import org.apache.hadoop.hbase.util.EnvironmentEdge;
+import org.apache.hadoop.hbase.util.EnvironmentEdgeManagerTestHelper;
+import org.junit.After;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+/**
+ * Test that the {@link SnapshotDescription} helper is helping correctly.
+ */
+@Category(SmallTests.class)
+public class TestSnapshotDescriptionUtils {
+  private static final HBaseTestingUtility UTIL = new HBaseTestingUtility();
+  private static FileSystem fs;
+  private static Path root;
+
+  @BeforeClass
+  public static void setupFS() throws Exception {
+    fs = UTIL.getTestFileSystem();
+    root = new Path(UTIL.getDataTestDir(), "hbase");
+  }
+
+  @After
+  public void cleanupFS() throws Exception {
+    if (fs.exists(root)) {
+    if (!fs.delete(root, true)) {
+      throw new IOException("Failed to delete root test dir: " + root);
+    }
+    if (!fs.mkdirs(root)) {
+      throw new IOException("Failed to create root test dir: " + root);
+    }
+    }
+  }
+
+  private static final Log LOG = LogFactory.getLog(TestSnapshotDescriptionUtils.class);
+
+  @Test
+  public void testValidateDescriptor() {
+    EnvironmentEdge edge = new EnvironmentEdge() {
+      @Override
+      public long currentTimeMillis() {
+        return 0;
+      }
+    };
+    EnvironmentEdgeManagerTestHelper.injectEdge(edge);
+
+    // check a basic snapshot description
+    SnapshotDescription.Builder builder = SnapshotDescription.newBuilder();
+    builder.setName("snapshot");
+    builder.setTable("table");
+
+    // check that time is to an amount in the future
+    Configuration conf = new Configuration(false);
+    conf.setLong(SnapshotDescriptionUtils.TIMESTAMP_SNAPSHOT_SPLIT_POINT_ADDITION, 1);
+    SnapshotDescription desc = SnapshotDescriptionUtils.validate(builder.build(), conf);
+    assertEquals("Description creation time wasn't set correctly", 1, desc.getCreationTime());
+
+    // test a global snapshot
+    edge = new EnvironmentEdge() {
+      @Override
+      public long currentTimeMillis() {
+        return 2;
+      }
+    };
+    EnvironmentEdgeManagerTestHelper.injectEdge(edge);
+    builder.setType(Type.GLOBAL);
+    desc = SnapshotDescriptionUtils.validate(builder.build(), conf);
+    assertEquals("Description creation time wasn't set correctly", 2, desc.getCreationTime());
+
+    // test that we don't override a given value
+    builder.setCreationTime(10);
+    desc = SnapshotDescriptionUtils.validate(builder.build(), conf);
+    assertEquals("Description creation time wasn't set correctly", 10, desc.getCreationTime());
+
+    try {
+      SnapshotDescriptionUtils.validate(SnapshotDescription.newBuilder().setName("fail").build(),
+        conf);
+      fail("Snapshot was considered valid without a table name");
+    } catch (IllegalArgumentException e) {
+      LOG.debug("Correctly failed when snapshot doesn't have a tablename");
+    }
+  }
+
+  /**
+   * Test that we throw an exception if there is no working snapshot directory when we attempt to
+   * 'complete' the snapshot
+   * @throws Exception on failure
+   */
+  @Test
+  public void testCompleteSnapshotWithNoSnapshotDirectoryFailure() throws Exception {
+    Path snapshotDir = new Path(root, ".snapshot");
+    Path tmpDir = new Path(snapshotDir, ".tmp");
+    Path workingDir = new Path(tmpDir, "not_a_snapshot");
+    assertFalse("Already have working snapshot dir: " + workingDir
+        + " but shouldn't. Test file leak?", fs.exists(workingDir));
+    SnapshotDescription snapshot = SnapshotDescription.newBuilder().setName("snapshot").build();
+    try {
+      SnapshotDescriptionUtils.completeSnapshot(snapshot, root, workingDir, fs);
+      fail("Shouldn't successfully complete move of a non-existent directory.");
+    } catch (IOException e) {
+      LOG.info("Correctly failed to move non-existant directory: " + e.getMessage());
+    }
+  }
+}