HBASE-14309 Allow load balancer to operate when there is region in transition by adding force flag

2015-08-29 13:15:53 -07:00 · 2015-08-29 13:15:53 -07:00 · df341c4299
parent 4256128fa2
commit df341c4299
10 changed files with 363 additions and 213 deletions
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java
@ -780,6 +780,16 @@ public interface Admin extends Abortable, Closeable {
   */
  boolean balancer() throws IOException;

+  /**
+   * Invoke the balancer.  Will run the balancer and if regions to move, it will
+   * go ahead and do the reassignments. If there is region in transition, force parameter of true
+   * would still run balancer. Can *not* run for other reasons.  Check
+   * logs.
+   * @param force whether we should force balance even if there is region in transition
+   * @return True if balancer ran, false otherwise.
+   */
+  boolean balancer(boolean force) throws IOException;
+  
  /**
   * Query the current state of the balancer
   *
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java
@ -2153,7 +2153,17 @@ public class HBaseAdmin implements Admin {
    return executeCallable(new MasterCallable<Boolean>(getConnection()) {
      @Override
      public Boolean call(int callTimeout) throws ServiceException {
-        return master.balance(null, RequestConverter.buildBalanceRequest()).getBalancerRan();
+        return master.balance(null, RequestConverter.buildBalanceRequest(false)).getBalancerRan();
+      }
+    });
+  }
+
+  @Override
+  public boolean balancer(final boolean force) throws IOException {
+    return executeCallable(new MasterCallable<Boolean>(getConnection()) {
+      @Override
+      public Boolean call(int callTimeout) throws ServiceException {
+        return master.balance(null, RequestConverter.buildBalanceRequest(force)).getBalancerRan();
      }
    });
  }
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/RequestConverter.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/RequestConverter.java
@ -1351,8 +1351,8 @@ public final class RequestConverter {
   *
   * @return a BalanceRequest
   */
-  public static BalanceRequest buildBalanceRequest() {
-    return BalanceRequest.newBuilder().build();
+  public static BalanceRequest buildBalanceRequest(boolean force) {
+    return BalanceRequest.newBuilder().setForce(force).build();
  }

  /**
--- a/hbase-protocol/src/main/java/org/apache/hadoop/hbase/protobuf/generated/MasterProtos.java
+++ b/hbase-protocol/src/main/java/org/apache/hadoop/hbase/protobuf/generated/MasterProtos.java
@ -25568,6 +25568,16 @@ public final class MasterProtos {

  public interface BalanceRequestOrBuilder
      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional bool force = 1;
+    /**
+     * <code>optional bool force = 1;</code>
+     */
+    boolean hasForce();
+    /**
+     * <code>optional bool force = 1;</code>
+     */
+    boolean getForce();
  }
  /**
   * Protobuf type {@code hbase.pb.BalanceRequest}
@ -25602,6 +25612,7 @@ public final class MasterProtos {
        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
        throws com.google.protobuf.InvalidProtocolBufferException {
      initFields();
+      int mutable_bitField0_ = 0;
      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
          com.google.protobuf.UnknownFieldSet.newBuilder();
      try {
@ -25619,6 +25630,11 @@ public final class MasterProtos {
              }
              break;
            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              force_ = input.readBool();
+              break;
+            }
          }
        }
      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
@ -25658,7 +25674,25 @@ public final class MasterProtos {
      return PARSER;
    }

+    private int bitField0_;
+    // optional bool force = 1;
+    public static final int FORCE_FIELD_NUMBER = 1;
+    private boolean force_;
+    /**
+     * <code>optional bool force = 1;</code>
+     */
+    public boolean hasForce() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional bool force = 1;</code>
+     */
+    public boolean getForce() {
+      return force_;
+    }
+
    private void initFields() {
+      force_ = false;
    }
    private byte memoizedIsInitialized = -1;
    public final boolean isInitialized() {
@ -25672,6 +25706,9 @@ public final class MasterProtos {
    public void writeTo(com.google.protobuf.CodedOutputStream output)
                        throws java.io.IOException {
      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeBool(1, force_);
+      }
      getUnknownFields().writeTo(output);
    }

@ -25681,6 +25718,10 @@ public final class MasterProtos {
      if (size != -1) return size;

      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBoolSize(1, force_);
+      }
      size += getUnknownFields().getSerializedSize();
      memoizedSerializedSize = size;
      return size;
@ -25704,6 +25745,11 @@ public final class MasterProtos {
      org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest other = (org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest) obj;

      boolean result = true;
+      result = result && (hasForce() == other.hasForce());
+      if (hasForce()) {
+        result = result && (getForce()
+            == other.getForce());
+      }
      result = result &&
          getUnknownFields().equals(other.getUnknownFields());
      return result;
@ -25717,6 +25763,10 @@ public final class MasterProtos {
      }
      int hash = 41;
      hash = (19 * hash) + getDescriptorForType().hashCode();
+      if (hasForce()) {
+        hash = (37 * hash) + FORCE_FIELD_NUMBER;
+        hash = (53 * hash) + hashBoolean(getForce());
+      }
      hash = (29 * hash) + getUnknownFields().hashCode();
      memoizedHashCode = hash;
      return hash;
@ -25826,6 +25876,8 @@ public final class MasterProtos {

      public Builder clear() {
        super.clear();
+        force_ = false;
+        bitField0_ = (bitField0_ & ~0x00000001);
        return this;
      }

@ -25852,6 +25904,13 @@ public final class MasterProtos {

      public org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest buildPartial() {
        org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest result = new org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.force_ = force_;
+        result.bitField0_ = to_bitField0_;
        onBuilt();
        return result;
      }
@ -25867,6 +25926,9 @@ public final class MasterProtos {

      public Builder mergeFrom(org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest other) {
        if (other == org.apache.hadoop.hbase.protobuf.generated.MasterProtos.BalanceRequest.getDefaultInstance()) return this;
+        if (other.hasForce()) {
+          setForce(other.getForce());
+        }
        this.mergeUnknownFields(other.getUnknownFields());
        return this;
      }
@ -25892,6 +25954,40 @@ public final class MasterProtos {
        }
        return this;
      }
+      private int bitField0_;
+
+      // optional bool force = 1;
+      private boolean force_ ;
+      /**
+       * <code>optional bool force = 1;</code>
+       */
+      public boolean hasForce() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional bool force = 1;</code>
+       */
+      public boolean getForce() {
+        return force_;
+      }
+      /**
+       * <code>optional bool force = 1;</code>
+       */
+      public Builder setForce(boolean value) {
+        bitField0_ |= 0x00000001;
+        force_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional bool force = 1;</code>
+       */
+      public Builder clearForce() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        force_ = false;
+        onChanged();
+        return this;
+      }

      // @@protoc_insertion_point(builder_scope:hbase.pb.BalanceRequest)
    }
@ -56609,208 +56705,209 @@ public final class MasterProtos {
      "paceResponse\022&\n\ttableName\030\001 \003(\0132\023.hbase.",
      "pb.TableName\"\021\n\017ShutdownRequest\"\022\n\020Shutd" +
      "ownResponse\"\023\n\021StopMasterRequest\"\024\n\022Stop" +
-      "MasterResponse\"\020\n\016BalanceRequest\"\'\n\017Bala" +
-      "nceResponse\022\024\n\014balancer_ran\030\001 \002(\010\"<\n\031Set" +
-      "BalancerRunningRequest\022\n\n\002on\030\001 \002(\010\022\023\n\013sy" +
-      "nchronous\030\002 \001(\010\"8\n\032SetBalancerRunningRes" +
-      "ponse\022\032\n\022prev_balance_value\030\001 \001(\010\"\032\n\030IsB" +
-      "alancerEnabledRequest\",\n\031IsBalancerEnabl" +
-      "edResponse\022\017\n\007enabled\030\001 \002(\010\"\027\n\025RunCatalo" +
-      "gScanRequest\"-\n\026RunCatalogScanResponse\022\023",
-      "\n\013scan_result\030\001 \001(\005\"-\n\033EnableCatalogJani" +
-      "torRequest\022\016\n\006enable\030\001 \002(\010\"2\n\034EnableCata" +
-      "logJanitorResponse\022\022\n\nprev_value\030\001 \001(\010\" " +
-      "\n\036IsCatalogJanitorEnabledRequest\"0\n\037IsCa" +
-      "talogJanitorEnabledResponse\022\r\n\005value\030\001 \002" +
-      "(\010\"B\n\017SnapshotRequest\022/\n\010snapshot\030\001 \002(\0132" +
-      "\035.hbase.pb.SnapshotDescription\",\n\020Snapsh" +
-      "otResponse\022\030\n\020expected_timeout\030\001 \002(\003\"\036\n\034" +
-      "GetCompletedSnapshotsRequest\"Q\n\035GetCompl" +
-      "etedSnapshotsResponse\0220\n\tsnapshots\030\001 \003(\013",
-      "2\035.hbase.pb.SnapshotDescription\"H\n\025Delet" +
-      "eSnapshotRequest\022/\n\010snapshot\030\001 \002(\0132\035.hba" +
-      "se.pb.SnapshotDescription\"\030\n\026DeleteSnaps" +
-      "hotResponse\"I\n\026RestoreSnapshotRequest\022/\n" +
-      "\010snapshot\030\001 \002(\0132\035.hbase.pb.SnapshotDescr" +
-      "iption\"\031\n\027RestoreSnapshotResponse\"H\n\025IsS" +
-      "napshotDoneRequest\022/\n\010snapshot\030\001 \001(\0132\035.h" +
-      "base.pb.SnapshotDescription\"^\n\026IsSnapsho" +
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-      "apshot\030\002 \001(\0132\035.hbase.pb.SnapshotDescript",
-      "ion\"O\n\034IsRestoreSnapshotDoneRequest\022/\n\010s" +
-      "napshot\030\001 \001(\0132\035.hbase.pb.SnapshotDescrip" +
-      "tion\"4\n\035IsRestoreSnapshotDoneResponse\022\023\n" +
-      "\004done\030\001 \001(\010:\005false\"F\n\033GetSchemaAlterStat" +
-      "usRequest\022\'\n\ntable_name\030\001 \002(\0132\023.hbase.pb" +
-      ".TableName\"T\n\034GetSchemaAlterStatusRespon" +
-      "se\022\035\n\025yet_to_update_regions\030\001 \001(\r\022\025\n\rtot" +
-      "al_regions\030\002 \001(\r\"\213\001\n\032GetTableDescriptors" +
-      "Request\022(\n\013table_names\030\001 \003(\0132\023.hbase.pb." +
-      "TableName\022\r\n\005regex\030\002 \001(\t\022!\n\022include_sys_",
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-      "tTableNamesRequest\022\r\n\005regex\030\001 \001(\t\022!\n\022inc" +
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-      "tTableStateRequest\022\'\n\ntable_name\030\001 \002(\0132\023" +
-      ".hbase.pb.TableName\"B\n\025GetTableStateResp" +
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-      "se\022\023\n\004done\030\001 \001(\010:\005false\0220\n\010snapshot\030\002 \001(" +
-      "\0132\036.hbase.pb.ProcedureDescription\",\n\031Get" +
-      "ProcedureResultRequest\022\017\n\007proc_id\030\001 \002(\004\"" +
-      "\371\001\n\032GetProcedureResultResponse\0229\n\005state\030" +
-      "\001 \002(\0162*.hbase.pb.GetProcedureResultRespo" +
-      "nse.State\022\022\n\nstart_time\030\002 \001(\004\022\023\n\013last_up" +
-      "date\030\003 \001(\004\022\016\n\006result\030\004 \001(\014\0224\n\texception\030" +
-      "\005 \001(\0132!.hbase.pb.ForeignExceptionMessage" +
-      "\"1\n\005State\022\r\n\tNOT_FOUND\020\000\022\013\n\007RUNNING\020\001\022\014\n",
-      "\010FINISHED\020\002\"\315\001\n\017SetQuotaRequest\022\021\n\tuser_" +
-      "name\030\001 \001(\t\022\022\n\nuser_group\030\002 \001(\t\022\021\n\tnamesp" +
-      "ace\030\003 \001(\t\022\'\n\ntable_name\030\004 \001(\0132\023.hbase.pb" +
-      ".TableName\022\022\n\nremove_all\030\005 \001(\010\022\026\n\016bypass" +
-      "_globals\030\006 \001(\010\022+\n\010throttle\030\007 \001(\0132\031.hbase" +
-      ".pb.ThrottleRequest\"\022\n\020SetQuotaResponse\"" +
-      "J\n\037MajorCompactionTimestampRequest\022\'\n\nta" +
-      "ble_name\030\001 \002(\0132\023.hbase.pb.TableName\"U\n(M" +
-      "ajorCompactionTimestampForRegionRequest\022" +
-      ")\n\006region\030\001 \002(\0132\031.hbase.pb.RegionSpecifi",
-      "er\"@\n MajorCompactionTimestampResponse\022\034" +
-      "\n\024compaction_timestamp\030\001 \002(\003\"\035\n\033Security" +
-      "CapabilitiesRequest\"\354\001\n\034SecurityCapabili" +
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-      "THORIZATION\020\002\022\026\n\022CELL_AUTHORIZATION\020\003\022\023\n" +
-      "\017CELL_VISIBILITY\020\0042\301#\n\rMasterService\022e\n\024" +
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-      "\032%.hbase.pb.GetTableDescriptorsResponse\022" +
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-      "ispatchMergingRegionsRequest\032(.hbase.pb.",
-      "DispatchMergingRegionsResponse\022M\n\014Assign" +
-      "Region\022\035.hbase.pb.AssignRegionRequest\032\036." +
-      "hbase.pb.AssignRegionResponse\022S\n\016Unassig" +
-      "nRegion\022\037.hbase.pb.UnassignRegionRequest" +
-      "\032 .hbase.pb.UnassignRegionResponse\022P\n\rOf" +
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-      "est\032\037.hbase.pb.OfflineRegionResponse\022J\n\013" +
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-      "\022V\n\017IsProcedureDone\022 .hbase.pb.IsProcedu" +
-      "reDoneRequest\032!.hbase.pb.IsProcedureDone" +
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-      "odifyNamespaceRequest\032!.hbase.pb.ModifyN",
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-      "\032\037.hbase.pb.GetTableStateResponse\022A\n\010Set" +
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-      "onTimestampRequest\032*.hbase.pb.MajorCompa" +
-      "ctionTimestampResponse\022\212\001\n(getLastMajorC" +
-      "ompactionTimestampForRegion\0222.hbase.pb.M" +
-      "ajorCompactionTimestampForRegionRequest\032" +
-      "*.hbase.pb.MajorCompactionTimestampRespo" +
-      "nse\022_\n\022getProcedureResult\022#.hbase.pb.Get" +
-      "ProcedureResultRequest\032$.hbase.pb.GetPro" +
-      "cedureResultResponse\022h\n\027getSecurityCapab",
-      "ilities\022%.hbase.pb.SecurityCapabilitiesR" +
-      "equest\032&.hbase.pb.SecurityCapabilitiesRe" +
-      "sponseBB\n*org.apache.hadoop.hbase.protob" +
-      "uf.generatedB\014MasterProtosH\001\210\001\001\240\001\001"
+      "MasterResponse\"\037\n\016BalanceRequest\022\r\n\005forc" +
+      "e\030\001 \001(\010\"\'\n\017BalanceResponse\022\024\n\014balancer_r" +
+      "an\030\001 \002(\010\"<\n\031SetBalancerRunningRequest\022\n\n" +
+      "\002on\030\001 \002(\010\022\023\n\013synchronous\030\002 \001(\010\"8\n\032SetBal" +
+      "ancerRunningResponse\022\032\n\022prev_balance_val" +
+      "ue\030\001 \001(\010\"\032\n\030IsBalancerEnabledRequest\",\n\031" +
+      "IsBalancerEnabledResponse\022\017\n\007enabled\030\001 \002" +
+      "(\010\"\027\n\025RunCatalogScanRequest\"-\n\026RunCatalo",
+      "gScanResponse\022\023\n\013scan_result\030\001 \001(\005\"-\n\033En" +
+      "ableCatalogJanitorRequest\022\016\n\006enable\030\001 \002(" +
+      "\010\"2\n\034EnableCatalogJanitorResponse\022\022\n\npre" +
+      "v_value\030\001 \001(\010\" \n\036IsCatalogJanitorEnabled" +
+      "Request\"0\n\037IsCatalogJanitorEnabledRespon" +
+      "se\022\r\n\005value\030\001 \002(\010\"B\n\017SnapshotRequest\022/\n\010" +
+      "snapshot\030\001 \002(\0132\035.hbase.pb.SnapshotDescri" +
+      "ption\",\n\020SnapshotResponse\022\030\n\020expected_ti" +
+      "meout\030\001 \002(\003\"\036\n\034GetCompletedSnapshotsRequ" +
+      "est\"Q\n\035GetCompletedSnapshotsResponse\0220\n\t",
+      "snapshots\030\001 \003(\0132\035.hbase.pb.SnapshotDescr" +
+      "iption\"H\n\025DeleteSnapshotRequest\022/\n\010snaps" +
+      "hot\030\001 \002(\0132\035.hbase.pb.SnapshotDescription" +
+      "\"\030\n\026DeleteSnapshotResponse\"I\n\026RestoreSna" +
+      "pshotRequest\022/\n\010snapshot\030\001 \002(\0132\035.hbase.p" +
+      "b.SnapshotDescription\"\031\n\027RestoreSnapshot" +
+      "Response\"H\n\025IsSnapshotDoneRequest\022/\n\010sna" +
+      "pshot\030\001 \001(\0132\035.hbase.pb.SnapshotDescripti" +
+      "on\"^\n\026IsSnapshotDoneResponse\022\023\n\004done\030\001 \001" +
+      "(\010:\005false\022/\n\010snapshot\030\002 \001(\0132\035.hbase.pb.S",
+      "napshotDescription\"O\n\034IsRestoreSnapshotD" +
+      "oneRequest\022/\n\010snapshot\030\001 \001(\0132\035.hbase.pb." +
+      "SnapshotDescription\"4\n\035IsRestoreSnapshot" +
+      "DoneResponse\022\023\n\004done\030\001 \001(\010:\005false\"F\n\033Get" +
+      "SchemaAlterStatusRequest\022\'\n\ntable_name\030\001" +
+      " \002(\0132\023.hbase.pb.TableName\"T\n\034GetSchemaAl" +
+      "terStatusResponse\022\035\n\025yet_to_update_regio" +
+      "ns\030\001 \001(\r\022\025\n\rtotal_regions\030\002 \001(\r\"\213\001\n\032GetT" +
+      "ableDescriptorsRequest\022(\n\013table_names\030\001 " +
+      "\003(\0132\023.hbase.pb.TableName\022\r\n\005regex\030\002 \001(\t\022",
+      "!\n\022include_sys_tables\030\003 \001(\010:\005false\022\021\n\tna" +
+      "mespace\030\004 \001(\t\"J\n\033GetTableDescriptorsResp" +
+      "onse\022+\n\014table_schema\030\001 \003(\0132\025.hbase.pb.Ta" +
+      "bleSchema\"[\n\024GetTableNamesRequest\022\r\n\005reg" +
+      "ex\030\001 \001(\t\022!\n\022include_sys_tables\030\002 \001(\010:\005fa" +
+      "lse\022\021\n\tnamespace\030\003 \001(\t\"A\n\025GetTableNamesR" +
+      "esponse\022(\n\013table_names\030\001 \003(\0132\023.hbase.pb." +
+      "TableName\"?\n\024GetTableStateRequest\022\'\n\ntab" +
+      "le_name\030\001 \002(\0132\023.hbase.pb.TableName\"B\n\025Ge" +
+      "tTableStateResponse\022)\n\013table_state\030\001 \002(\013",
+      "2\024.hbase.pb.TableState\"\031\n\027GetClusterStat" +
+      "usRequest\"K\n\030GetClusterStatusResponse\022/\n" +
+      "\016cluster_status\030\001 \002(\0132\027.hbase.pb.Cluster" +
+      "Status\"\030\n\026IsMasterRunningRequest\"4\n\027IsMa" +
+      "sterRunningResponse\022\031\n\021is_master_running" +
+      "\030\001 \002(\010\"I\n\024ExecProcedureRequest\0221\n\tproced" +
+      "ure\030\001 \002(\0132\036.hbase.pb.ProcedureDescriptio" +
+      "n\"F\n\025ExecProcedureResponse\022\030\n\020expected_t" +
+      "imeout\030\001 \001(\003\022\023\n\013return_data\030\002 \001(\014\"K\n\026IsP" +
+      "rocedureDoneRequest\0221\n\tprocedure\030\001 \001(\0132\036",
+      ".hbase.pb.ProcedureDescription\"`\n\027IsProc" +
+      "edureDoneResponse\022\023\n\004done\030\001 \001(\010:\005false\0220" +
+      "\n\010snapshot\030\002 \001(\0132\036.hbase.pb.ProcedureDes" +
+      "cription\",\n\031GetProcedureResultRequest\022\017\n" +
+      "\007proc_id\030\001 \002(\004\"\371\001\n\032GetProcedureResultRes" +
+      "ponse\0229\n\005state\030\001 \002(\0162*.hbase.pb.GetProce" +
+      "dureResultResponse.State\022\022\n\nstart_time\030\002" +
+      " \001(\004\022\023\n\013last_update\030\003 \001(\004\022\016\n\006result\030\004 \001(" +
+      "\014\0224\n\texception\030\005 \001(\0132!.hbase.pb.ForeignE" +
+      "xceptionMessage\"1\n\005State\022\r\n\tNOT_FOUND\020\000\022",
+      "\013\n\007RUNNING\020\001\022\014\n\010FINISHED\020\002\"\315\001\n\017SetQuotaR" +
+      "equest\022\021\n\tuser_name\030\001 \001(\t\022\022\n\nuser_group\030" +
+      "\002 \001(\t\022\021\n\tnamespace\030\003 \001(\t\022\'\n\ntable_name\030\004" +
+      " \001(\0132\023.hbase.pb.TableName\022\022\n\nremove_all\030" +
+      "\005 \001(\010\022\026\n\016bypass_globals\030\006 \001(\010\022+\n\010throttl" +
+      "e\030\007 \001(\0132\031.hbase.pb.ThrottleRequest\"\022\n\020Se" +
+      "tQuotaResponse\"J\n\037MajorCompactionTimesta" +
+      "mpRequest\022\'\n\ntable_name\030\001 \002(\0132\023.hbase.pb" +
+      ".TableName\"U\n(MajorCompactionTimestampFo" +
+      "rRegionRequest\022)\n\006region\030\001 \002(\0132\031.hbase.p",
+      "b.RegionSpecifier\"@\n MajorCompactionTime" +
+      "stampResponse\022\034\n\024compaction_timestamp\030\001 " +
+      "\002(\003\"\035\n\033SecurityCapabilitiesRequest\"\354\001\n\034S" +
+      "ecurityCapabilitiesResponse\022G\n\014capabilit" +
+      "ies\030\001 \003(\01621.hbase.pb.SecurityCapabilitie" +
+      "sResponse.Capability\"\202\001\n\nCapability\022\031\n\025S" +
+      "IMPLE_AUTHENTICATION\020\000\022\031\n\025SECURE_AUTHENT" +
+      "ICATION\020\001\022\021\n\rAUTHORIZATION\020\002\022\026\n\022CELL_AUT" +
+      "HORIZATION\020\003\022\023\n\017CELL_VISIBILITY\020\0042\301#\n\rMa" +
+      "sterService\022e\n\024GetSchemaAlterStatus\022%.hb",
+      "ase.pb.GetSchemaAlterStatusRequest\032&.hba" +
+      "se.pb.GetSchemaAlterStatusResponse\022b\n\023Ge" +
+      "tTableDescriptors\022$.hbase.pb.GetTableDes" +
+      "criptorsRequest\032%.hbase.pb.GetTableDescr" +
+      "iptorsResponse\022P\n\rGetTableNames\022\036.hbase." +
+      "pb.GetTableNamesRequest\032\037.hbase.pb.GetTa" +
+      "bleNamesResponse\022Y\n\020GetClusterStatus\022!.h" +
+      "base.pb.GetClusterStatusRequest\032\".hbase." +
+      "pb.GetClusterStatusResponse\022V\n\017IsMasterR" +
+      "unning\022 .hbase.pb.IsMasterRunningRequest",
+      "\032!.hbase.pb.IsMasterRunningResponse\022D\n\tA" +
+      "ddColumn\022\032.hbase.pb.AddColumnRequest\032\033.h" +
+      "base.pb.AddColumnResponse\022M\n\014DeleteColum" +
+      "n\022\035.hbase.pb.DeleteColumnRequest\032\036.hbase" +
+      ".pb.DeleteColumnResponse\022M\n\014ModifyColumn" +
+      "\022\035.hbase.pb.ModifyColumnRequest\032\036.hbase." +
+      "pb.ModifyColumnResponse\022G\n\nMoveRegion\022\033." +
+      "hbase.pb.MoveRegionRequest\032\034.hbase.pb.Mo" +
+      "veRegionResponse\022k\n\026DispatchMergingRegio" +
+      "ns\022\'.hbase.pb.DispatchMergingRegionsRequ",
+      "est\032(.hbase.pb.DispatchMergingRegionsRes" +
+      "ponse\022M\n\014AssignRegion\022\035.hbase.pb.AssignR" +
+      "egionRequest\032\036.hbase.pb.AssignRegionResp" +
+      "onse\022S\n\016UnassignRegion\022\037.hbase.pb.Unassi" +
+      "gnRegionRequest\032 .hbase.pb.UnassignRegio" +
+      "nResponse\022P\n\rOfflineRegion\022\036.hbase.pb.Of" +
+      "flineRegionRequest\032\037.hbase.pb.OfflineReg" +
+      "ionResponse\022J\n\013DeleteTable\022\034.hbase.pb.De" +
+      "leteTableRequest\032\035.hbase.pb.DeleteTableR" +
+      "esponse\022P\n\rtruncateTable\022\036.hbase.pb.Trun",
+      "cateTableRequest\032\037.hbase.pb.TruncateTabl" +
+      "eResponse\022J\n\013EnableTable\022\034.hbase.pb.Enab" +
+      "leTableRequest\032\035.hbase.pb.EnableTableRes" +
+      "ponse\022M\n\014DisableTable\022\035.hbase.pb.Disable" +
+      "TableRequest\032\036.hbase.pb.DisableTableResp" +
+      "onse\022J\n\013ModifyTable\022\034.hbase.pb.ModifyTab" +
+      "leRequest\032\035.hbase.pb.ModifyTableResponse" +
+      "\022J\n\013CreateTable\022\034.hbase.pb.CreateTableRe" +
+      "quest\032\035.hbase.pb.CreateTableResponse\022A\n\010" +
+      "Shutdown\022\031.hbase.pb.ShutdownRequest\032\032.hb",
+      "ase.pb.ShutdownResponse\022G\n\nStopMaster\022\033." +
+      "hbase.pb.StopMasterRequest\032\034.hbase.pb.St" +
+      "opMasterResponse\022>\n\007Balance\022\030.hbase.pb.B" +
+      "alanceRequest\032\031.hbase.pb.BalanceResponse" +
+      "\022_\n\022SetBalancerRunning\022#.hbase.pb.SetBal" +
+      "ancerRunningRequest\032$.hbase.pb.SetBalanc" +
+      "erRunningResponse\022\\\n\021IsBalancerEnabled\022\"" +
+      ".hbase.pb.IsBalancerEnabledRequest\032#.hba" +
+      "se.pb.IsBalancerEnabledResponse\022S\n\016RunCa" +
+      "talogScan\022\037.hbase.pb.RunCatalogScanReque",
+      "st\032 .hbase.pb.RunCatalogScanResponse\022e\n\024" +
+      "EnableCatalogJanitor\022%.hbase.pb.EnableCa" +
+      "talogJanitorRequest\032&.hbase.pb.EnableCat" +
+      "alogJanitorResponse\022n\n\027IsCatalogJanitorE" +
+      "nabled\022(.hbase.pb.IsCatalogJanitorEnable" +
+      "dRequest\032).hbase.pb.IsCatalogJanitorEnab" +
+      "ledResponse\022^\n\021ExecMasterService\022#.hbase" +
+      ".pb.CoprocessorServiceRequest\032$.hbase.pb" +
+      ".CoprocessorServiceResponse\022A\n\010Snapshot\022" +
+      "\031.hbase.pb.SnapshotRequest\032\032.hbase.pb.Sn",
+      "apshotResponse\022h\n\025GetCompletedSnapshots\022" +
+      "&.hbase.pb.GetCompletedSnapshotsRequest\032" +
+      "\'.hbase.pb.GetCompletedSnapshotsResponse" +
+      "\022S\n\016DeleteSnapshot\022\037.hbase.pb.DeleteSnap" +
+      "shotRequest\032 .hbase.pb.DeleteSnapshotRes" +
+      "ponse\022S\n\016IsSnapshotDone\022\037.hbase.pb.IsSna" +
+      "pshotDoneRequest\032 .hbase.pb.IsSnapshotDo" +
+      "neResponse\022V\n\017RestoreSnapshot\022 .hbase.pb" +
+      ".RestoreSnapshotRequest\032!.hbase.pb.Resto" +
+      "reSnapshotResponse\022h\n\025IsRestoreSnapshotD",
+      "one\022&.hbase.pb.IsRestoreSnapshotDoneRequ" +
+      "est\032\'.hbase.pb.IsRestoreSnapshotDoneResp" +
+      "onse\022P\n\rExecProcedure\022\036.hbase.pb.ExecPro" +
+      "cedureRequest\032\037.hbase.pb.ExecProcedureRe" +
+      "sponse\022W\n\024ExecProcedureWithRet\022\036.hbase.p" +
+      "b.ExecProcedureRequest\032\037.hbase.pb.ExecPr" +
+      "ocedureResponse\022V\n\017IsProcedureDone\022 .hba" +
+      "se.pb.IsProcedureDoneRequest\032!.hbase.pb." +
+      "IsProcedureDoneResponse\022V\n\017ModifyNamespa" +
+      "ce\022 .hbase.pb.ModifyNamespaceRequest\032!.h",
+      "base.pb.ModifyNamespaceResponse\022V\n\017Creat" +
+      "eNamespace\022 .hbase.pb.CreateNamespaceReq" +
+      "uest\032!.hbase.pb.CreateNamespaceResponse\022" +
+      "V\n\017DeleteNamespace\022 .hbase.pb.DeleteName" +
+      "spaceRequest\032!.hbase.pb.DeleteNamespaceR" +
+      "esponse\022k\n\026GetNamespaceDescriptor\022\'.hbas" +
+      "e.pb.GetNamespaceDescriptorRequest\032(.hba" +
+      "se.pb.GetNamespaceDescriptorResponse\022q\n\030" +
+      "ListNamespaceDescriptors\022).hbase.pb.List" +
+      "NamespaceDescriptorsRequest\032*.hbase.pb.L",
+      "istNamespaceDescriptorsResponse\022\206\001\n\037List" +
+      "TableDescriptorsByNamespace\0220.hbase.pb.L" +
+      "istTableDescriptorsByNamespaceRequest\0321." +
+      "hbase.pb.ListTableDescriptorsByNamespace" +
+      "Response\022t\n\031ListTableNamesByNamespace\022*." +
+      "hbase.pb.ListTableNamesByNamespaceReques" +
+      "t\032+.hbase.pb.ListTableNamesByNamespaceRe" +
+      "sponse\022P\n\rGetTableState\022\036.hbase.pb.GetTa" +
+      "bleStateRequest\032\037.hbase.pb.GetTableState" +
+      "Response\022A\n\010SetQuota\022\031.hbase.pb.SetQuota",
+      "Request\032\032.hbase.pb.SetQuotaResponse\022x\n\037g" +
+      "etLastMajorCompactionTimestamp\022).hbase.p" +
+      "b.MajorCompactionTimestampRequest\032*.hbas" +
+      "e.pb.MajorCompactionTimestampResponse\022\212\001" +
+      "\n(getLastMajorCompactionTimestampForRegi" +
+      "on\0222.hbase.pb.MajorCompactionTimestampFo" +
+      "rRegionRequest\032*.hbase.pb.MajorCompactio" +
+      "nTimestampResponse\022_\n\022getProcedureResult" +
+      "\022#.hbase.pb.GetProcedureResultRequest\032$." +
+      "hbase.pb.GetProcedureResultResponse\022h\n\027g",
+      "etSecurityCapabilities\022%.hbase.pb.Securi" +
+      "tyCapabilitiesRequest\032&.hbase.pb.Securit" +
+      "yCapabilitiesResponseBB\n*org.apache.hado" +
+      "op.hbase.protobuf.generatedB\014MasterProto" +
+      "sH\001\210\001\001\240\001\001"
    };
    com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
      new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
@ -57098,7 +57195,7 @@ public final class MasterProtos {
          internal_static_hbase_pb_BalanceRequest_fieldAccessorTable = new
            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
              internal_static_hbase_pb_BalanceRequest_descriptor,
-              new java.lang.String[] { });
+              new java.lang.String[] { "Force", });
          internal_static_hbase_pb_BalanceResponse_descriptor =
            getDescriptor().getMessageTypes().get(47);
          internal_static_hbase_pb_BalanceResponse_fieldAccessorTable = new
--- a/hbase-protocol/src/main/protobuf/Master.proto
+++ b/hbase-protocol/src/main/protobuf/Master.proto
@ -249,6 +249,7 @@ message StopMasterResponse {
 }

 message BalanceRequest {
+  optional bool force = 1;
 }

 message BalanceResponse {
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
@ -1224,6 +1224,10 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
  }

  public boolean balance() throws IOException {
+    return balance(false);
+  }
+
+  public boolean balance(boolean force) throws IOException {
    // if master not initialized, don't run balancer.
    if (!this.initialized) {
      LOG.debug("Master has not been initialized, don't run balancer.");
@ -1238,10 +1242,14 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
      if (this.assignmentManager.getRegionStates().isRegionsInTransition()) {
        Map<String, RegionState> regionsInTransition =
          this.assignmentManager.getRegionStates().getRegionsInTransition();
-        LOG.debug("Not running balancer because " + regionsInTransition.size() +
+        // if hbase:meta region is in transition, result of assignment cannot be recorded
+        // ignore the force flag in that case
+        boolean metaInTransition = assignmentManager.getRegionStates().isMetaRegionInTransition();
+        String prefix = force && !metaInTransition ? "R" : "Not r";
+        LOG.debug(prefix + "unning balancer because " + regionsInTransition.size() +
          " region(s) in transition: " + org.apache.commons.lang.StringUtils.
            abbreviate(regionsInTransition.toString(), 256));
-        return false;
+        if (!force || metaInTransition) return false;
      }
      if (this.serverManager.areDeadServersInProgress()) {
        LOG.debug("Not running balancer because processing dead regionserver(s): " +
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java
@ -413,7 +413,8 @@ public class MasterRpcServices extends RSRpcServices
  public BalanceResponse balance(RpcController controller,
      BalanceRequest request) throws ServiceException {
    try {
-      return BalanceResponse.newBuilder().setBalancerRan(master.balance()).build();
+      return BalanceResponse.newBuilder().setBalancerRan(master.balance(
+        request.hasForce() ? request.getForce() : false)).build();
    } catch (IOException ex) {
      throw new ServiceException(ex);
    }
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/RegionStates.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/RegionStates.java
@ -228,6 +228,16 @@ public class RegionStates {
    return !regionsInTransition.isEmpty();
  }

+  /**
+   * @return True if hbase:meta table region is in transition.
+   */
+  public synchronized boolean isMetaRegionInTransition() {
+    for (RegionState state : regionsInTransition.values()) {
+      if (state.getRegion().isMetaRegion()) return true;
+    }
+    return false;
+  }
+
  /**
   * @return True if specified region assigned, and not in transition.
   */
--- a/hbase-shell/src/main/ruby/hbase/admin.rb
+++ b/hbase-shell/src/main/ruby/hbase/admin.rb
@ -102,8 +102,8 @@ module Hbase
    #----------------------------------------------------------------------------------------------
    # Requests a cluster balance
    # Returns true if balancer ran
-    def balancer()
-      @admin.balancer()
+    def balancer(force)
+      @admin.balancer(java.lang.Boolean::valueOf(force))
    end

    #----------------------------------------------------------------------------------------------
--- a/hbase-shell/src/main/ruby/shell/commands/balancer.rb
+++ b/hbase-shell/src/main/ruby/shell/commands/balancer.rb
@ -25,13 +25,26 @@ module Shell
 Trigger the cluster balancer. Returns true if balancer ran and was able to
 tell the region servers to unassign all the regions to balance  (the re-assignment itself is async). 
 Otherwise false (Will not run if regions in transition).
+Parameter tells master whether we should force balance even if there is region in transition.
+
+WARNING: For experts only. Forcing a balance may do more damage than repair
+when assignment is confused
+
+Examples:
+
+  hbase> balancer
+  hbase> balancer "force"
 EOF
      end

-      def command()
+      def command(force=nil)
        format_simple_command do
          formatter.row([
-            admin.balancer()? "true": "false"
+            if force.nil?
+              admin.balancer("false")? "true": "false"
+            elsif force == "force"
+              admin.balancer("true")? "true": "false"
+            end
          ])
        end
      end