diff --git 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
index 90d576434bb..4f7f9545ecd 100644
--- 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
@@ -34206,6 +34206,21 @@ public final class MasterProtos {
      * <code>optional bool include_sys_tables = 3 [default = false];</code>
      */
     boolean getIncludeSysTables();
+
+    // optional string namespace = 4;
+    /**
+     * <code>optional string namespace = 4;</code>
+     */
+    boolean hasNamespace();
+    /**
+     * <code>optional string namespace = 4;</code>
+     */
+    java.lang.String getNamespace();
+    /**
+     * <code>optional string namespace = 4;</code>
+     */
+    com.google.protobuf.ByteString
+        getNamespaceBytes();
   }
   /**
    * Protobuf type {@code GetTableDescriptorsRequest}
@@ -34276,6 +34291,11 @@ public final class MasterProtos {
               includeSysTables_ = input.readBool();
               break;
             }
+            case 34: {
+              bitField0_ |= 0x00000004;
+              namespace_ = input.readBytes();
+              break;
+            }
           }
         }
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
@@ -34414,10 +34434,54 @@ public final class MasterProtos {
       return includeSysTables_;
     }
 
+    // optional string namespace = 4;
+    public static final int NAMESPACE_FIELD_NUMBER = 4;
+    private java.lang.Object namespace_;
+    /**
+     * <code>optional string namespace = 4;</code>
+     */
+    public boolean hasNamespace() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional string namespace = 4;</code>
+     */
+    public java.lang.String getNamespace() {
+      java.lang.Object ref = namespace_;
+      if (ref instanceof java.lang.String) {
+        return (java.lang.String) ref;
+      } else {
+        com.google.protobuf.ByteString bs = 
+            (com.google.protobuf.ByteString) ref;
+        java.lang.String s = bs.toStringUtf8();
+        if (bs.isValidUtf8()) {
+          namespace_ = s;
+        }
+        return s;
+      }
+    }
+    /**
+     * <code>optional string namespace = 4;</code>
+     */
+    public com.google.protobuf.ByteString
+        getNamespaceBytes() {
+      java.lang.Object ref = namespace_;
+      if (ref instanceof java.lang.String) {
+        com.google.protobuf.ByteString b = 
+            com.google.protobuf.ByteString.copyFromUtf8(
+                (java.lang.String) ref);
+        namespace_ = b;
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+
     private void initFields() {
       tableNames_ = java.util.Collections.emptyList();
       regex_ = "";
       includeSysTables_ = false;
+      namespace_ = "";
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
@@ -34446,6 +34510,9 @@ public final class MasterProtos {
       if (((bitField0_ & 0x00000002) == 0x00000002)) {
         output.writeBool(3, includeSysTables_);
       }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(4, getNamespaceBytes());
+      }
       getUnknownFields().writeTo(output);
     }
 
@@ -34467,6 +34534,10 @@ public final class MasterProtos {
         size += com.google.protobuf.CodedOutputStream
           .computeBoolSize(3, includeSysTables_);
       }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(4, getNamespaceBytes());
+      }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
       return size;
@@ -34502,6 +34573,11 @@ public final class MasterProtos {
         result = result && (getIncludeSysTables()
             == other.getIncludeSysTables());
       }
+      result = result && (hasNamespace() == other.hasNamespace());
+      if (hasNamespace()) {
+        result = result && getNamespace()
+            .equals(other.getNamespace());
+      }
       result = result &&
           getUnknownFields().equals(other.getUnknownFields());
       return result;
@@ -34527,6 +34603,10 @@ public final class MasterProtos {
         hash = (37 * hash) + INCLUDE_SYS_TABLES_FIELD_NUMBER;
         hash = (53 * hash) + hashBoolean(getIncludeSysTables());
       }
+      if (hasNamespace()) {
+        hash = (37 * hash) + NAMESPACE_FIELD_NUMBER;
+        hash = (53 * hash) + getNamespace().hashCode();
+      }
       hash = (29 * hash) + getUnknownFields().hashCode();
       memoizedHashCode = hash;
       return hash;
@@ -34647,6 +34727,8 @@ public final class MasterProtos {
         bitField0_ = (bitField0_ & ~0x00000002);
         includeSysTables_ = false;
         bitField0_ = (bitField0_ & ~0x00000004);
+        namespace_ = "";
+        bitField0_ = (bitField0_ & ~0x00000008);
         return this;
       }
 
@@ -34692,6 +34774,10 @@ public final class MasterProtos {
           to_bitField0_ |= 0x00000002;
         }
         result.includeSysTables_ = includeSysTables_;
+        if (((from_bitField0_ & 0x00000008) == 0x00000008)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.namespace_ = namespace_;
         result.bitField0_ = to_bitField0_;
         onBuilt();
         return result;
@@ -34742,6 +34828,11 @@ public final class MasterProtos {
         if (other.hasIncludeSysTables()) {
           setIncludeSysTables(other.getIncludeSysTables());
         }
+        if (other.hasNamespace()) {
+          bitField0_ |= 0x00000008;
+          namespace_ = other.namespace_;
+          onChanged();
+        }
         this.mergeUnknownFields(other.getUnknownFields());
         return this;
       }
@@ -35122,6 +35213,80 @@ public final class MasterProtos {
         return this;
       }
 
+      // optional string namespace = 4;
+      private java.lang.Object namespace_ = "";
+      /**
+       * <code>optional string namespace = 4;</code>
+       */
+      public boolean hasNamespace() {
+        return ((bitField0_ & 0x00000008) == 0x00000008);
+      }
+      /**
+       * <code>optional string namespace = 4;</code>
+       */
+      public java.lang.String getNamespace() {
+        java.lang.Object ref = namespace_;
+        if (!(ref instanceof java.lang.String)) {
+          java.lang.String s = ((com.google.protobuf.ByteString) ref)
+              .toStringUtf8();
+          namespace_ = s;
+          return s;
+        } else {
+          return (java.lang.String) ref;
+        }
+      }
+      /**
+       * <code>optional string namespace = 4;</code>
+       */
+      public com.google.protobuf.ByteString
+          getNamespaceBytes() {
+        java.lang.Object ref = namespace_;
+        if (ref instanceof String) {
+          com.google.protobuf.ByteString b = 
+              com.google.protobuf.ByteString.copyFromUtf8(
+                  (java.lang.String) ref);
+          namespace_ = b;
+          return b;
+        } else {
+          return (com.google.protobuf.ByteString) ref;
+        }
+      }
+      /**
+       * <code>optional string namespace = 4;</code>
+       */
+      public Builder setNamespace(
+          java.lang.String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        namespace_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional string namespace = 4;</code>
+       */
+      public Builder clearNamespace() {
+        bitField0_ = (bitField0_ & ~0x00000008);
+        namespace_ = getDefaultInstance().getNamespace();
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional string namespace = 4;</code>
+       */
+      public Builder setNamespaceBytes(
+          com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000008;
+        namespace_ = value;
+        onChanged();
+        return this;
+      }
+
       // @@protoc_insertion_point(builder_scope:GetTableDescriptorsRequest)
     }
 
@@ -35881,6 +36046,21 @@ public final class MasterProtos {
      * <code>optional bool include_sys_tables = 2 [default = false];</code>
      */
     boolean getIncludeSysTables();
+
+    // optional string namespace = 3;
+    /**
+     * <code>optional string namespace = 3;</code>
+     */
+    boolean hasNamespace();
+    /**
+     * <code>optional string namespace = 3;</code>
+     */
+    java.lang.String getNamespace();
+    /**
+     * <code>optional string namespace = 3;</code>
+     */
+    com.google.protobuf.ByteString
+        getNamespaceBytes();
   }
   /**
    * Protobuf type {@code GetTableNamesRequest}
@@ -35943,6 +36123,11 @@ public final class MasterProtos {
               includeSysTables_ = input.readBool();
               break;
             }
+            case 26: {
+              bitField0_ |= 0x00000004;
+              namespace_ = input.readBytes();
+              break;
+            }
           }
         }
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
@@ -36042,9 +36227,53 @@ public final class MasterProtos {
       return includeSysTables_;
     }
 
+    // optional string namespace = 3;
+    public static final int NAMESPACE_FIELD_NUMBER = 3;
+    private java.lang.Object namespace_;
+    /**
+     * <code>optional string namespace = 3;</code>
+     */
+    public boolean hasNamespace() {
+      return ((bitField0_ & 0x00000004) == 0x00000004);
+    }
+    /**
+     * <code>optional string namespace = 3;</code>
+     */
+    public java.lang.String getNamespace() {
+      java.lang.Object ref = namespace_;
+      if (ref instanceof java.lang.String) {
+        return (java.lang.String) ref;
+      } else {
+        com.google.protobuf.ByteString bs = 
+            (com.google.protobuf.ByteString) ref;
+        java.lang.String s = bs.toStringUtf8();
+        if (bs.isValidUtf8()) {
+          namespace_ = s;
+        }
+        return s;
+      }
+    }
+    /**
+     * <code>optional string namespace = 3;</code>
+     */
+    public com.google.protobuf.ByteString
+        getNamespaceBytes() {
+      java.lang.Object ref = namespace_;
+      if (ref instanceof java.lang.String) {
+        com.google.protobuf.ByteString b = 
+            com.google.protobuf.ByteString.copyFromUtf8(
+                (java.lang.String) ref);
+        namespace_ = b;
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+
     private void initFields() {
       regex_ = "";
       includeSysTables_ = false;
+      namespace_ = "";
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
@@ -36064,6 +36293,9 @@ public final class MasterProtos {
       if (((bitField0_ & 0x00000002) == 0x00000002)) {
         output.writeBool(2, includeSysTables_);
       }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        output.writeBytes(3, getNamespaceBytes());
+      }
       getUnknownFields().writeTo(output);
     }
 
@@ -36081,6 +36313,10 @@ public final class MasterProtos {
         size += com.google.protobuf.CodedOutputStream
           .computeBoolSize(2, includeSysTables_);
       }
+      if (((bitField0_ & 0x00000004) == 0x00000004)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeBytesSize(3, getNamespaceBytes());
+      }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
       return size;
@@ -36114,6 +36350,11 @@ public final class MasterProtos {
         result = result && (getIncludeSysTables()
             == other.getIncludeSysTables());
       }
+      result = result && (hasNamespace() == other.hasNamespace());
+      if (hasNamespace()) {
+        result = result && getNamespace()
+            .equals(other.getNamespace());
+      }
       result = result &&
           getUnknownFields().equals(other.getUnknownFields());
       return result;
@@ -36135,6 +36376,10 @@ public final class MasterProtos {
         hash = (37 * hash) + INCLUDE_SYS_TABLES_FIELD_NUMBER;
         hash = (53 * hash) + hashBoolean(getIncludeSysTables());
       }
+      if (hasNamespace()) {
+        hash = (37 * hash) + NAMESPACE_FIELD_NUMBER;
+        hash = (53 * hash) + getNamespace().hashCode();
+      }
       hash = (29 * hash) + getUnknownFields().hashCode();
       memoizedHashCode = hash;
       return hash;
@@ -36248,6 +36493,8 @@ public final class MasterProtos {
         bitField0_ = (bitField0_ & ~0x00000001);
         includeSysTables_ = false;
         bitField0_ = (bitField0_ & ~0x00000002);
+        namespace_ = "";
+        bitField0_ = (bitField0_ & ~0x00000004);
         return this;
       }
 
@@ -36284,6 +36531,10 @@ public final class MasterProtos {
           to_bitField0_ |= 0x00000002;
         }
         result.includeSysTables_ = includeSysTables_;
+        if (((from_bitField0_ & 0x00000004) == 0x00000004)) {
+          to_bitField0_ |= 0x00000004;
+        }
+        result.namespace_ = namespace_;
         result.bitField0_ = to_bitField0_;
         onBuilt();
         return result;
@@ -36308,6 +36559,11 @@ public final class MasterProtos {
         if (other.hasIncludeSysTables()) {
           setIncludeSysTables(other.getIncludeSysTables());
         }
+        if (other.hasNamespace()) {
+          bitField0_ |= 0x00000004;
+          namespace_ = other.namespace_;
+          onChanged();
+        }
         this.mergeUnknownFields(other.getUnknownFields());
         return this;
       }
@@ -36442,6 +36698,80 @@ public final class MasterProtos {
         return this;
       }
 
+      // optional string namespace = 3;
+      private java.lang.Object namespace_ = "";
+      /**
+       * <code>optional string namespace = 3;</code>
+       */
+      public boolean hasNamespace() {
+        return ((bitField0_ & 0x00000004) == 0x00000004);
+      }
+      /**
+       * <code>optional string namespace = 3;</code>
+       */
+      public java.lang.String getNamespace() {
+        java.lang.Object ref = namespace_;
+        if (!(ref instanceof java.lang.String)) {
+          java.lang.String s = ((com.google.protobuf.ByteString) ref)
+              .toStringUtf8();
+          namespace_ = s;
+          return s;
+        } else {
+          return (java.lang.String) ref;
+        }
+      }
+      /**
+       * <code>optional string namespace = 3;</code>
+       */
+      public com.google.protobuf.ByteString
+          getNamespaceBytes() {
+        java.lang.Object ref = namespace_;
+        if (ref instanceof String) {
+          com.google.protobuf.ByteString b = 
+              com.google.protobuf.ByteString.copyFromUtf8(
+                  (java.lang.String) ref);
+          namespace_ = b;
+          return b;
+        } else {
+          return (com.google.protobuf.ByteString) ref;
+        }
+      }
+      /**
+       * <code>optional string namespace = 3;</code>
+       */
+      public Builder setNamespace(
+          java.lang.String value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        namespace_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional string namespace = 3;</code>
+       */
+      public Builder clearNamespace() {
+        bitField0_ = (bitField0_ & ~0x00000004);
+        namespace_ = getDefaultInstance().getNamespace();
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional string namespace = 3;</code>
+       */
+      public Builder setNamespaceBytes(
+          com.google.protobuf.ByteString value) {
+        if (value == null) {
+    throw new NullPointerException();
+  }
+  bitField0_ |= 0x00000004;
+        namespace_ = value;
+        onChanged();
+        return this;
+      }
+
       // @@protoc_insertion_point(builder_scope:GetTableNamesRequest)
     }
 
@@ -48349,115 +48679,116 @@ public final class MasterProtos {
       "equest\022\036\n\ntable_name\030\001 \002(\0132\n.TableName\"T",
       "\n\034GetSchemaAlterStatusResponse\022\035\n\025yet_to" +
       "_update_regions\030\001 \001(\r\022\025\n\rtotal_regions\030\002" +
-      " \001(\r\"o\n\032GetTableDescriptorsRequest\022\037\n\013ta" +
-      "ble_names\030\001 \003(\0132\n.TableName\022\r\n\005regex\030\002 \001" +
-      "(\t\022!\n\022include_sys_tables\030\003 \001(\010:\005false\"A\n" +
-      "\033GetTableDescriptorsResponse\022\"\n\014table_sc" +
-      "hema\030\001 \003(\0132\014.TableSchema\"H\n\024GetTableName" +
-      "sRequest\022\r\n\005regex\030\001 \001(\t\022!\n\022include_sys_t" +
-      "ables\030\002 \001(\010:\005false\"8\n\025GetTableNamesRespo" +
-      "nse\022\037\n\013table_names\030\001 \003(\0132\n.TableName\"6\n\024",
-      "GetTableStateRequest\022\036\n\ntable_name\030\001 \002(\013" +
-      "2\n.TableName\"9\n\025GetTableStateResponse\022 \n" +
-      "\013table_state\030\001 \002(\0132\013.TableState\"\031\n\027GetCl" +
-      "usterStatusRequest\"B\n\030GetClusterStatusRe" +
-      "sponse\022&\n\016cluster_status\030\001 \002(\0132\016.Cluster" +
-      "Status\"\030\n\026IsMasterRunningRequest\"4\n\027IsMa" +
-      "sterRunningResponse\022\031\n\021is_master_running" +
-      "\030\001 \002(\010\"@\n\024ExecProcedureRequest\022(\n\tproced" +
-      "ure\030\001 \002(\0132\025.ProcedureDescription\"F\n\025Exec" +
-      "ProcedureResponse\022\030\n\020expected_timeout\030\001 ",
-      "\001(\003\022\023\n\013return_data\030\002 \001(\014\"B\n\026IsProcedureD" +
-      "oneRequest\022(\n\tprocedure\030\001 \001(\0132\025.Procedur" +
-      "eDescription\"W\n\027IsProcedureDoneResponse\022" +
-      "\023\n\004done\030\001 \001(\010:\005false\022\'\n\010snapshot\030\002 \001(\0132\025" +
-      ".ProcedureDescription\"\273\001\n\017SetQuotaReques" +
-      "t\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\036\n\ntable_name\030\004 \001(\0132" +
-      "\n.TableName\022\022\n\nremove_all\030\005 \001(\010\022\026\n\016bypas" +
-      "s_globals\030\006 \001(\010\022\"\n\010throttle\030\007 \001(\0132\020.Thro" +
-      "ttleRequest\"\022\n\020SetQuotaResponse2\346\030\n\rMast",
-      "erService\022S\n\024GetSchemaAlterStatus\022\034.GetS" +
-      "chemaAlterStatusRequest\032\035.GetSchemaAlter" +
-      "StatusResponse\022P\n\023GetTableDescriptors\022\033." +
-      "GetTableDescriptorsRequest\032\034.GetTableDes" +
-      "criptorsResponse\022>\n\rGetTableNames\022\025.GetT" +
-      "ableNamesRequest\032\026.GetTableNamesResponse" +
-      "\022G\n\020GetClusterStatus\022\030.GetClusterStatusR" +
-      "equest\032\031.GetClusterStatusResponse\022D\n\017IsM" +
-      "asterRunning\022\027.IsMasterRunningRequest\032\030." +
-      "IsMasterRunningResponse\0222\n\tAddColumn\022\021.A",
-      "ddColumnRequest\032\022.AddColumnResponse\022;\n\014D" +
-      "eleteColumn\022\024.DeleteColumnRequest\032\025.Dele" +
-      "teColumnResponse\022;\n\014ModifyColumn\022\024.Modif" +
-      "yColumnRequest\032\025.ModifyColumnResponse\0225\n" +
-      "\nMoveRegion\022\022.MoveRegionRequest\032\023.MoveRe" +
-      "gionResponse\022Y\n\026DispatchMergingRegions\022\036" +
-      ".DispatchMergingRegionsRequest\032\037.Dispatc" +
-      "hMergingRegionsResponse\022;\n\014AssignRegion\022" +
-      "\024.AssignRegionRequest\032\025.AssignRegionResp" +
-      "onse\022A\n\016UnassignRegion\022\026.UnassignRegionR",
-      "equest\032\027.UnassignRegionResponse\022>\n\rOffli" +
-      "neRegion\022\025.OfflineRegionRequest\032\026.Offlin" +
-      "eRegionResponse\0228\n\013DeleteTable\022\023.DeleteT" +
-      "ableRequest\032\024.DeleteTableResponse\022>\n\rtru" +
-      "ncateTable\022\025.TruncateTableRequest\032\026.Trun" +
-      "cateTableResponse\0228\n\013EnableTable\022\023.Enabl" +
-      "eTableRequest\032\024.EnableTableResponse\022;\n\014D" +
-      "isableTable\022\024.DisableTableRequest\032\025.Disa" +
-      "bleTableResponse\0228\n\013ModifyTable\022\023.Modify" +
-      "TableRequest\032\024.ModifyTableResponse\0228\n\013Cr",
-      "eateTable\022\023.CreateTableRequest\032\024.CreateT" +
-      "ableResponse\022/\n\010Shutdown\022\020.ShutdownReque" +
-      "st\032\021.ShutdownResponse\0225\n\nStopMaster\022\022.St" +
-      "opMasterRequest\032\023.StopMasterResponse\022,\n\007" +
-      "Balance\022\017.BalanceRequest\032\020.BalanceRespon" +
-      "se\022M\n\022SetBalancerRunning\022\032.SetBalancerRu" +
-      "nningRequest\032\033.SetBalancerRunningRespons" +
-      "e\022A\n\016RunCatalogScan\022\026.RunCatalogScanRequ" +
-      "est\032\027.RunCatalogScanResponse\022S\n\024EnableCa" +
-      "talogJanitor\022\034.EnableCatalogJanitorReque",
-      "st\032\035.EnableCatalogJanitorResponse\022\\\n\027IsC" +
-      "atalogJanitorEnabled\022\037.IsCatalogJanitorE" +
-      "nabledRequest\032 .IsCatalogJanitorEnabledR" +
-      "esponse\022L\n\021ExecMasterService\022\032.Coprocess" +
-      "orServiceRequest\032\033.CoprocessorServiceRes" +
-      "ponse\022/\n\010Snapshot\022\020.SnapshotRequest\032\021.Sn" +
-      "apshotResponse\022V\n\025GetCompletedSnapshots\022" +
-      "\035.GetCompletedSnapshotsRequest\032\036.GetComp" +
-      "letedSnapshotsResponse\022A\n\016DeleteSnapshot" +
-      "\022\026.DeleteSnapshotRequest\032\027.DeleteSnapsho",
-      "tResponse\022A\n\016IsSnapshotDone\022\026.IsSnapshot" +
-      "DoneRequest\032\027.IsSnapshotDoneResponse\022D\n\017" +
-      "RestoreSnapshot\022\027.RestoreSnapshotRequest" +
-      "\032\030.RestoreSnapshotResponse\022V\n\025IsRestoreS" +
-      "napshotDone\022\035.IsRestoreSnapshotDoneReque" +
-      "st\032\036.IsRestoreSnapshotDoneResponse\022>\n\rEx" +
-      "ecProcedure\022\025.ExecProcedureRequest\032\026.Exe" +
-      "cProcedureResponse\022E\n\024ExecProcedureWithR" +
-      "et\022\025.ExecProcedureRequest\032\026.ExecProcedur" +
-      "eResponse\022D\n\017IsProcedureDone\022\027.IsProcedu",
-      "reDoneRequest\032\030.IsProcedureDoneResponse\022" +
-      "D\n\017ModifyNamespace\022\027.ModifyNamespaceRequ" +
-      "est\032\030.ModifyNamespaceResponse\022D\n\017CreateN" +
-      "amespace\022\027.CreateNamespaceRequest\032\030.Crea" +
-      "teNamespaceResponse\022D\n\017DeleteNamespace\022\027" +
-      ".DeleteNamespaceRequest\032\030.DeleteNamespac" +
-      "eResponse\022Y\n\026GetNamespaceDescriptor\022\036.Ge" +
-      "tNamespaceDescriptorRequest\032\037.GetNamespa" +
-      "ceDescriptorResponse\022_\n\030ListNamespaceDes" +
-      "criptors\022 .ListNamespaceDescriptorsReque",
-      "st\032!.ListNamespaceDescriptorsResponse\022t\n" +
-      "\037ListTableDescriptorsByNamespace\022\'.ListT" +
-      "ableDescriptorsByNamespaceRequest\032(.List" +
-      "TableDescriptorsByNamespaceResponse\022b\n\031L" +
-      "istTableNamesByNamespace\022!.ListTableName" +
-      "sByNamespaceRequest\032\".ListTableNamesByNa" +
-      "mespaceResponse\022>\n\rGetTableState\022\025.GetTa" +
-      "bleStateRequest\032\026.GetTableStateResponse\022" +
-      "/\n\010SetQuota\022\020.SetQuotaRequest\032\021.SetQuota" +
-      "ResponseBB\n*org.apache.hadoop.hbase.prot",
-      "obuf.generatedB\014MasterProtosH\001\210\001\001\240\001\001"
+      " \001(\r\"\202\001\n\032GetTableDescriptorsRequest\022\037\n\013t" +
+      "able_names\030\001 \003(\0132\n.TableName\022\r\n\005regex\030\002 " +
+      "\001(\t\022!\n\022include_sys_tables\030\003 \001(\010:\005false\022\021" +
+      "\n\tnamespace\030\004 \001(\t\"A\n\033GetTableDescriptors" +
+      "Response\022\"\n\014table_schema\030\001 \003(\0132\014.TableSc" +
+      "hema\"[\n\024GetTableNamesRequest\022\r\n\005regex\030\001 " +
+      "\001(\t\022!\n\022include_sys_tables\030\002 \001(\010:\005false\022\021" +
+      "\n\tnamespace\030\003 \001(\t\"8\n\025GetTableNamesRespon",
+      "se\022\037\n\013table_names\030\001 \003(\0132\n.TableName\"6\n\024G" +
+      "etTableStateRequest\022\036\n\ntable_name\030\001 \002(\0132" +
+      "\n.TableName\"9\n\025GetTableStateResponse\022 \n\013" +
+      "table_state\030\001 \002(\0132\013.TableState\"\031\n\027GetClu" +
+      "sterStatusRequest\"B\n\030GetClusterStatusRes" +
+      "ponse\022&\n\016cluster_status\030\001 \002(\0132\016.ClusterS" +
+      "tatus\"\030\n\026IsMasterRunningRequest\"4\n\027IsMas" +
+      "terRunningResponse\022\031\n\021is_master_running\030" +
+      "\001 \002(\010\"@\n\024ExecProcedureRequest\022(\n\tprocedu" +
+      "re\030\001 \002(\0132\025.ProcedureDescription\"F\n\025ExecP",
+      "rocedureResponse\022\030\n\020expected_timeout\030\001 \001" +
+      "(\003\022\023\n\013return_data\030\002 \001(\014\"B\n\026IsProcedureDo" +
+      "neRequest\022(\n\tprocedure\030\001 \001(\0132\025.Procedure" +
+      "Description\"W\n\027IsProcedureDoneResponse\022\023" +
+      "\n\004done\030\001 \001(\010:\005false\022\'\n\010snapshot\030\002 \001(\0132\025." +
+      "ProcedureDescription\"\273\001\n\017SetQuotaRequest" +
+      "\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\036\n\ntable_name\030\004 \001(\0132\n" +
+      ".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\020.Throt",
+      "tleRequest\"\022\n\020SetQuotaResponse2\346\030\n\rMaste" +
+      "rService\022S\n\024GetSchemaAlterStatus\022\034.GetSc" +
+      "hemaAlterStatusRequest\032\035.GetSchemaAlterS" +
+      "tatusResponse\022P\n\023GetTableDescriptors\022\033.G" +
+      "etTableDescriptorsRequest\032\034.GetTableDesc" +
+      "riptorsResponse\022>\n\rGetTableNames\022\025.GetTa" +
+      "bleNamesRequest\032\026.GetTableNamesResponse\022" +
+      "G\n\020GetClusterStatus\022\030.GetClusterStatusRe" +
+      "quest\032\031.GetClusterStatusResponse\022D\n\017IsMa" +
+      "sterRunning\022\027.IsMasterRunningRequest\032\030.I",
+      "sMasterRunningResponse\0222\n\tAddColumn\022\021.Ad" +
+      "dColumnRequest\032\022.AddColumnResponse\022;\n\014De" +
+      "leteColumn\022\024.DeleteColumnRequest\032\025.Delet" +
+      "eColumnResponse\022;\n\014ModifyColumn\022\024.Modify" +
+      "ColumnRequest\032\025.ModifyColumnResponse\0225\n\n" +
+      "MoveRegion\022\022.MoveRegionRequest\032\023.MoveReg" +
+      "ionResponse\022Y\n\026DispatchMergingRegions\022\036." +
+      "DispatchMergingRegionsRequest\032\037.Dispatch" +
+      "MergingRegionsResponse\022;\n\014AssignRegion\022\024" +
+      ".AssignRegionRequest\032\025.AssignRegionRespo",
+      "nse\022A\n\016UnassignRegion\022\026.UnassignRegionRe" +
+      "quest\032\027.UnassignRegionResponse\022>\n\rOfflin" +
+      "eRegion\022\025.OfflineRegionRequest\032\026.Offline" +
+      "RegionResponse\0228\n\013DeleteTable\022\023.DeleteTa" +
+      "bleRequest\032\024.DeleteTableResponse\022>\n\rtrun" +
+      "cateTable\022\025.TruncateTableRequest\032\026.Trunc" +
+      "ateTableResponse\0228\n\013EnableTable\022\023.Enable" +
+      "TableRequest\032\024.EnableTableResponse\022;\n\014Di" +
+      "sableTable\022\024.DisableTableRequest\032\025.Disab" +
+      "leTableResponse\0228\n\013ModifyTable\022\023.ModifyT",
+      "ableRequest\032\024.ModifyTableResponse\0228\n\013Cre" +
+      "ateTable\022\023.CreateTableRequest\032\024.CreateTa" +
+      "bleResponse\022/\n\010Shutdown\022\020.ShutdownReques" +
+      "t\032\021.ShutdownResponse\0225\n\nStopMaster\022\022.Sto" +
+      "pMasterRequest\032\023.StopMasterResponse\022,\n\007B" +
+      "alance\022\017.BalanceRequest\032\020.BalanceRespons" +
+      "e\022M\n\022SetBalancerRunning\022\032.SetBalancerRun" +
+      "ningRequest\032\033.SetBalancerRunningResponse" +
+      "\022A\n\016RunCatalogScan\022\026.RunCatalogScanReque" +
+      "st\032\027.RunCatalogScanResponse\022S\n\024EnableCat",
+      "alogJanitor\022\034.EnableCatalogJanitorReques" +
+      "t\032\035.EnableCatalogJanitorResponse\022\\\n\027IsCa" +
+      "talogJanitorEnabled\022\037.IsCatalogJanitorEn" +
+      "abledRequest\032 .IsCatalogJanitorEnabledRe" +
+      "sponse\022L\n\021ExecMasterService\022\032.Coprocesso" +
+      "rServiceRequest\032\033.CoprocessorServiceResp" +
+      "onse\022/\n\010Snapshot\022\020.SnapshotRequest\032\021.Sna" +
+      "pshotResponse\022V\n\025GetCompletedSnapshots\022\035" +
+      ".GetCompletedSnapshotsRequest\032\036.GetCompl" +
+      "etedSnapshotsResponse\022A\n\016DeleteSnapshot\022",
+      "\026.DeleteSnapshotRequest\032\027.DeleteSnapshot" +
+      "Response\022A\n\016IsSnapshotDone\022\026.IsSnapshotD" +
+      "oneRequest\032\027.IsSnapshotDoneResponse\022D\n\017R" +
+      "estoreSnapshot\022\027.RestoreSnapshotRequest\032" +
+      "\030.RestoreSnapshotResponse\022V\n\025IsRestoreSn" +
+      "apshotDone\022\035.IsRestoreSnapshotDoneReques" +
+      "t\032\036.IsRestoreSnapshotDoneResponse\022>\n\rExe" +
+      "cProcedure\022\025.ExecProcedureRequest\032\026.Exec" +
+      "ProcedureResponse\022E\n\024ExecProcedureWithRe" +
+      "t\022\025.ExecProcedureRequest\032\026.ExecProcedure",
+      "Response\022D\n\017IsProcedureDone\022\027.IsProcedur" +
+      "eDoneRequest\032\030.IsProcedureDoneResponse\022D" +
+      "\n\017ModifyNamespace\022\027.ModifyNamespaceReque" +
+      "st\032\030.ModifyNamespaceResponse\022D\n\017CreateNa" +
+      "mespace\022\027.CreateNamespaceRequest\032\030.Creat" +
+      "eNamespaceResponse\022D\n\017DeleteNamespace\022\027." +
+      "DeleteNamespaceRequest\032\030.DeleteNamespace" +
+      "Response\022Y\n\026GetNamespaceDescriptor\022\036.Get" +
+      "NamespaceDescriptorRequest\032\037.GetNamespac" +
+      "eDescriptorResponse\022_\n\030ListNamespaceDesc",
+      "riptors\022 .ListNamespaceDescriptorsReques" +
+      "t\032!.ListNamespaceDescriptorsResponse\022t\n\037" +
+      "ListTableDescriptorsByNamespace\022\'.ListTa" +
+      "bleDescriptorsByNamespaceRequest\032(.ListT" +
+      "ableDescriptorsByNamespaceResponse\022b\n\031Li" +
+      "stTableNamesByNamespace\022!.ListTableNames" +
+      "ByNamespaceRequest\032\".ListTableNamesByNam" +
+      "espaceResponse\022>\n\rGetTableState\022\025.GetTab" +
+      "leStateRequest\032\026.GetTableStateResponse\022/" +
+      "\n\010SetQuota\022\020.SetQuotaRequest\032\021.SetQuotaR",
+      "esponseBB\n*org.apache.hadoop.hbase.proto" +
+      "buf.generatedB\014MasterProtosH\001\210\001\001\240\001\001"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
       new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
@@ -48889,7 +49220,7 @@ public final class MasterProtos {
           internal_static_GetTableDescriptorsRequest_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_GetTableDescriptorsRequest_descriptor,
-              new java.lang.String[] { "TableNames", "Regex", "IncludeSysTables", });
+              new java.lang.String[] { "TableNames", "Regex", "IncludeSysTables", "Namespace", });
           internal_static_GetTableDescriptorsResponse_descriptor =
             getDescriptor().getMessageTypes().get(71);
           internal_static_GetTableDescriptorsResponse_fieldAccessorTable = new
@@ -48901,7 +49232,7 @@ public final class MasterProtos {
           internal_static_GetTableNamesRequest_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_GetTableNamesRequest_descriptor,
-              new java.lang.String[] { "Regex", "IncludeSysTables", });
+              new java.lang.String[] { "Regex", "IncludeSysTables", "Namespace", });
           internal_static_GetTableNamesResponse_descriptor =
             getDescriptor().getMessageTypes().get(73);
           internal_static_GetTableNamesResponse_fieldAccessorTable = new
diff --git a/hbase-protocol/src/main/protobuf/Master.proto b/hbase-protocol/src/main/protobuf/Master.proto
index 82104f5ecdd..e55dcc0cd42 100644
--- a/hbase-protocol/src/main/protobuf/Master.proto
+++ b/hbase-protocol/src/main/protobuf/Master.proto
@@ -316,6 +316,7 @@ message GetTableDescriptorsRequest {
   repeated TableName table_names = 1;
   optional string regex = 2;
   optional bool include_sys_tables = 3 [default=false];
+  optional string namespace = 4;
 }
 
 message GetTableDescriptorsResponse {
@@ -325,6 +326,7 @@ message GetTableDescriptorsResponse {
 message GetTableNamesRequest {
   optional string regex = 1;
   optional bool include_sys_tables = 2 [default=false];
+  optional string namespace = 3;
 }
 
 message GetTableNamesResponse {
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterAndRegionObserver.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterAndRegionObserver.java
index 9d702fafb4d..fbf505e3822 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterAndRegionObserver.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterAndRegionObserver.java
@@ -158,6 +158,16 @@ public abstract class BaseMasterAndRegionObserver extends BaseRegionObserver
       NamespaceDescriptor ns) throws IOException {
   }
 
+  @Override
+  public void preListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException {
+  }
+
+  @Override
+  public void postListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException {
+  }
+
   @Override
   public void preAddColumn(ObserverContext<MasterCoprocessorEnvironment> ctx,
       TableName tableName, HColumnDescriptor column) throws IOException {
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterObserver.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterObserver.java
index b26e7d4988d..e33288d7203 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterObserver.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterObserver.java
@@ -151,6 +151,16 @@ public class BaseMasterObserver implements MasterObserver {
   public void postModifyNamespace(ObserverContext<MasterCoprocessorEnvironment> ctx, NamespaceDescriptor ns) throws IOException {
   }
 
+  @Override
+  public void preListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException {
+  }
+
+  @Override
+  public void postListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException {
+  }
+
   @Override
   public void preAddColumn(ObserverContext<MasterCoprocessorEnvironment> ctx,
       TableName tableName, HColumnDescriptor column) throws IOException {
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java
index 50912b36abe..bad2c5fdadf 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java
@@ -788,6 +788,25 @@ public interface MasterObserver extends Coprocessor {
   void postModifyNamespace(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       NamespaceDescriptor ns) throws IOException;
 
+  /**
+   * Called before a listNamespaceDescriptors request has been processed.
+   * @param ctx the environment to interact with the framework and master
+   * @param descriptors an empty list, can be filled with what to return if bypassing
+   * @throws IOException
+   */
+  void preListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException;
+
+  /**
+   * Called after a listNamespaceDescriptors request has been processed.
+   * @param ctx the environment to interact with the framework and master
+   * @param descriptors the list of descriptors about to be returned
+   * @throws IOException
+   */
+  void postListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException;
+
+
   /**
    * Called before the table memstore is flushed to disk.
    * @param ctx the environment to interact with the framework and master
diff --git 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
index b6175192204..3d87c679a25 100644
--- 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
@@ -140,7 +140,6 @@ import org.mortbay.jetty.nio.SelectChannelConnector;
 import org.mortbay.jetty.servlet.Context;
 
 import com.google.common.annotations.VisibleForTesting;
-import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.protobuf.Descriptors;
 import com.google.protobuf.Service;
@@ -2042,34 +2041,45 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
   @Override
   public List<NamespaceDescriptor> listNamespaceDescriptors() throws IOException {
     checkNamespaceManagerReady();
-    return Lists.newArrayList(tableNamespaceManager.list());
+
+    final List<NamespaceDescriptor> descriptors = new ArrayList<NamespaceDescriptor>();
+    boolean bypass = false;
+    if (cpHost != null) {
+      bypass = cpHost.preListNamespaceDescriptors(descriptors);
+    }
+
+    if (!bypass) {
+      descriptors.addAll(tableNamespaceManager.list());
+
+      if (cpHost != null) {
+        cpHost.postListNamespaceDescriptors(descriptors);
+      }
+    }
+    return descriptors;
   }
 
   @Override
   public List<HTableDescriptor> listTableDescriptorsByNamespace(String name) throws IOException {
     getNamespaceDescriptor(name); // check that namespace exists
-    return Lists.newArrayList(tableDescriptors.getByNamespace(name).values());
+    return listTableDescriptors(name, null, null, true);
   }
 
   @Override
   public List<TableName> listTableNamesByNamespace(String name) throws IOException {
-    List<TableName> tableNames = Lists.newArrayList();
     getNamespaceDescriptor(name); // check that namespace exists
-    for (HTableDescriptor descriptor: tableDescriptors.getByNamespace(name).values()) {
-      tableNames.add(descriptor.getTableName());
-    }
-    return tableNames;
+    return listTableNames(name, null, true);
   }
 
   /**
    * Returns the list of table descriptors that match the specified request
    *
+   * @param namespace the namespace to query, or null if querying for all
    * @param regex The regular expression to match against, or null if querying for all
    * @param tableNameList the list of table names, or null if querying for all
    * @param includeSysTables False to match only against userspace tables
    * @return the list of table descriptors
    */
-  public List<HTableDescriptor> listTableDescriptors(final String regex,
+  public List<HTableDescriptor> listTableDescriptors(final String namespace, final String regex,
       final List<TableName> tableNameList, final boolean includeSysTables)
       throws IOException {
     final List<HTableDescriptor> descriptors = new ArrayList<HTableDescriptor>();
@@ -2082,7 +2092,13 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
     if (!bypass) {
       if (tableNameList == null || tableNameList.size() == 0) {
         // request for all TableDescriptors
-        Collection<HTableDescriptor> htds = tableDescriptors.getAll().values();
+        Collection<HTableDescriptor> htds;
+        if (namespace != null && namespace.length() > 0) {
+          htds = tableDescriptors.getByNamespace(namespace).values();
+        } else {
+          htds = tableDescriptors.getAll().values();
+        }
+
         for (HTableDescriptor desc: htds) {
           if (includeSysTables || !desc.getTableName().isSystemTable()) {
             descriptors.add(desc);
@@ -2112,11 +2128,12 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
   /**
    * Returns the list of table names that match the specified request
    * @param regex The regular expression to match against, or null if querying for all
+   * @param namespace the namespace to query, or null if querying for all
    * @param includeSysTables False to match only against userspace tables
    * @return the list of table names
    */
-  public List<TableName> listTableNames(final String regex, final boolean includeSysTables)
-      throws IOException {
+  public List<TableName> listTableNames(final String namespace, final String regex,
+      final boolean includeSysTables) throws IOException {
     final List<HTableDescriptor> descriptors = new ArrayList<HTableDescriptor>();
 
     boolean bypass = false;
@@ -2126,7 +2143,13 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
 
     if (!bypass) {
       // get all descriptors
-      Collection<HTableDescriptor> htds = tableDescriptors.getAll().values();
+      Collection<HTableDescriptor> htds;
+      if (namespace != null && namespace.length() > 0) {
+        htds = tableDescriptors.getByNamespace(namespace).values();
+      } else {
+        htds = tableDescriptors.getAll().values();
+      }
+
       for (HTableDescriptor htd: htds) {
         if (includeSysTables || !htd.getTableName().isSystemTable()) {
           descriptors.add(htd);
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java
index cdddbfaa848..679e62a3321 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java
@@ -150,6 +150,28 @@ public class MasterCoprocessorHost
     });
   }
 
+  public boolean preListNamespaceDescriptors(final List<NamespaceDescriptor> descriptors)
+      throws IOException {
+    return execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
+      @Override
+      public void call(MasterObserver oserver, ObserverContext<MasterCoprocessorEnvironment> ctx)
+          throws IOException {
+        oserver.preListNamespaceDescriptors(ctx, descriptors);
+      }
+    });
+  }
+
+  public void postListNamespaceDescriptors(final List<NamespaceDescriptor> descriptors)
+      throws IOException {
+    execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
+      @Override
+      public void call(MasterObserver oserver, ObserverContext<MasterCoprocessorEnvironment> ctx)
+          throws IOException {
+        oserver.postListNamespaceDescriptors(ctx, descriptors);
+      }
+    });
+  }
+
   /* Implementation of hooks for invoking MasterObservers */
 
   public void preCreateTable(final HTableDescriptor htd, final HRegionInfo[] regions)
diff --git 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
index 1c413689289..84f4d362d2c 100644
--- 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
@@ -787,6 +787,7 @@ public class MasterRpcServices extends RSRpcServices
       master.checkInitialized();
 
       final String regex = req.hasRegex() ? req.getRegex() : null;
+      final String namespace = req.hasNamespace() ? req.getNamespace() : null;
       List<TableName> tableNameList = null;
       if (req.getTableNamesCount() > 0) {
         tableNameList = new ArrayList<TableName>(req.getTableNamesCount());
@@ -795,8 +796,8 @@ public class MasterRpcServices extends RSRpcServices
         }
       }
 
-      List<HTableDescriptor> descriptors = master.listTableDescriptors(regex, tableNameList,
-          req.getIncludeSysTables());
+      List<HTableDescriptor> descriptors = master.listTableDescriptors(namespace, regex,
+          tableNameList, req.getIncludeSysTables());
 
       GetTableDescriptorsResponse.Builder builder = GetTableDescriptorsResponse.newBuilder();
       if (descriptors != null && descriptors.size() > 0) {
@@ -825,7 +826,9 @@ public class MasterRpcServices extends RSRpcServices
       master.checkServiceStarted();
 
       final String regex = req.hasRegex() ? req.getRegex() : null;
-      List<TableName> tableNames = master.listTableNames(regex, req.getIncludeSysTables());
+      final String namespace = req.hasNamespace() ? req.getNamespace() : null;
+      List<TableName> tableNames = master.listTableNames(namespace, regex,
+          req.getIncludeSysTables());
 
       GetTableNamesResponse.Builder builder = GetTableNamesResponse.newBuilder();
       if (tableNames != null && tableNames.size() > 0) {
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java
index 6f3edd7ea80..f959bb051b1 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java
@@ -1206,6 +1206,22 @@ public class AccessController extends BaseMasterAndRegionObserver
     requireGlobalPermission("modifyNamespace", Action.ADMIN, ns.getName());
   }
 
+  @Override
+  public void postListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      List<NamespaceDescriptor> descriptors) throws IOException {
+    // Retains only those which passes authorization checks, as the checks weren't done as part
+    // of preGetTableDescriptors.
+    Iterator<NamespaceDescriptor> itr = descriptors.iterator();
+    while (itr.hasNext()) {
+      NamespaceDescriptor desc = itr.next();
+      try {
+        requireGlobalPermission("listNamespaces", Action.ADMIN, desc.getName());
+      } catch (AccessDeniedException e) {
+        itr.remove();
+      }
+    }
+  }
+
   @Override
   public void preTableFlush(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final TableName tableName) throws IOException {
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestMasterObserver.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestMasterObserver.java
index d3593cdf829..cca3496fdfe 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestMasterObserver.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestMasterObserver.java
@@ -93,6 +93,8 @@ public class TestMasterObserver {
     private boolean postDeleteNamespaceCalled;
     private boolean preModifyNamespaceCalled;
     private boolean postModifyNamespaceCalled;
+    private boolean preListNamespaceDescriptorsCalled;
+    private boolean postListNamespaceDescriptorsCalled;
     private boolean preAddColumnCalled;
     private boolean postAddColumnCalled;
     private boolean preModifyColumnCalled;
@@ -173,6 +175,8 @@ public class TestMasterObserver {
       postDeleteNamespaceCalled = false;
       preModifyNamespaceCalled = false;
       postModifyNamespaceCalled = false;
+      preListNamespaceDescriptorsCalled = false;
+      postListNamespaceDescriptorsCalled = false;
       preAddColumnCalled = false;
       postAddColumnCalled = false;
       preModifyColumnCalled = false;
@@ -394,6 +398,29 @@ public class TestMasterObserver {
       return preModifyNamespaceCalled && !postModifyNamespaceCalled;
     }
 
+    @Override
+    public void preListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> env,
+        List<NamespaceDescriptor> descriptors) throws IOException {
+      if (bypass) {
+        env.bypass();
+      }
+      preListNamespaceDescriptorsCalled = true;
+    }
+
+    @Override
+    public void postListNamespaceDescriptors(ObserverContext<MasterCoprocessorEnvironment> env,
+        List<NamespaceDescriptor> descriptors) throws IOException {
+      postListNamespaceDescriptorsCalled = true;
+    }
+
+    public boolean wasListNamespaceDescriptorsCalled() {
+      return preListNamespaceDescriptorsCalled && postListNamespaceDescriptorsCalled;
+    }
+
+    public boolean preListNamespaceDescriptorsCalledOnly() {
+      return preListNamespaceDescriptorsCalled && !postListNamespaceDescriptorsCalled;
+    }
+
     @Override
     public void preAddColumn(ObserverContext<MasterCoprocessorEnvironment> env,
         TableName tableName, HColumnDescriptor column) throws IOException {
@@ -1428,6 +1455,22 @@ public class TestMasterObserver {
 
     admin.createNamespace(NamespaceDescriptor.create(testNamespace).build());
     assertTrue("Test namespace should not be created", cp.preCreateNamespaceCalledOnly());
+
+    // turn on bypass, run the test
+    cp.enableBypass(true);
+    cp.resetStates();
+
+    admin.listNamespaceDescriptors();
+    assertTrue("post listNamespace should not have been called",
+               cp.preListNamespaceDescriptorsCalledOnly());
+
+    // turn off bypass, run the tests again
+    cp.enableBypass(false);
+    cp.resetStates();
+
+    admin.listNamespaceDescriptors();
+    assertTrue("post listNamespace should have been called",
+               cp.wasListNamespaceDescriptorsCalled());
   }
 
   private void modifyTableSync(Admin admin, TableName tableName, HTableDescriptor htd)
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestNamespaceCommands.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestNamespaceCommands.java
index 59f722e2585..e26a9ca6316 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestNamespaceCommands.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestNamespaceCommands.java
@@ -21,6 +21,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
 import java.util.List;
+import java.util.Arrays;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
@@ -29,6 +30,9 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.NamespaceDescriptor;
 import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.Admin;
+import org.apache.hadoop.hbase.client.Connection;
+import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.client.Get;
 import org.apache.hadoop.hbase.client.HTable;
 import org.apache.hadoop.hbase.client.Result;
@@ -187,6 +191,31 @@ public class TestNamespaceCommands extends SecureTestUtil {
     verifyDenied(deleteNamespace, USER_NSP_WRITE, USER_CREATE, USER_RW);
   }
 
+  @Test
+  public void testListNamespaces() throws Exception {
+    AccessTestAction listAction = new AccessTestAction() {
+      @Override
+      public Object run() throws Exception {
+        Connection unmanagedConnection =
+            ConnectionFactory.createConnection(UTIL.getConfiguration());
+        Admin admin = unmanagedConnection.getAdmin();
+        try {
+          return Arrays.asList(admin.listNamespaceDescriptors());
+        } finally {
+          admin.close();
+          unmanagedConnection.close();
+        }
+      }
+    };
+
+    verifyAllowed(listAction, SUPERUSER, USER_NSP_ADMIN);
+    verifyDenied(listAction, USER_NSP_WRITE, USER_CREATE, USER_RW);
+
+    // we have 3 namespaces: [default, hbase, TEST_NAMESPACE, TEST_NAMESPACE2]
+    assertEquals(4, ((List)SUPERUSER.runAs(listAction)).size());
+    assertEquals(2, ((List)USER_NSP_ADMIN.runAs(listAction)).size());
+  }
+
   @Test
   public void testGrantRevoke() throws Exception{
     final String testUser = "testUser";