HBASE-17600 Implement get/create/modify/delete/list namespace admin operations

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncAdmin.java

@@ -24,6 +24,7 @@ import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.NamespaceDescriptor;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
@@ -253,6 +254,37 @@ public interface AsyncAdmin {
   CompletableFuture<Void> modifyColumnFamily(final TableName tableName,
       final HColumnDescriptor columnFamily);
 
+  /**
+   * Create a new namespace.
+   * @param descriptor descriptor which describes the new namespace
+   */
+  CompletableFuture<Void> createNamespace(final NamespaceDescriptor descriptor);
+
+  /**
+   * Modify an existing namespace.
+   * @param descriptor descriptor which describes the new namespace
+   */
+  CompletableFuture<Void> modifyNamespace(final NamespaceDescriptor descriptor);
+
+  /**
+   * Delete an existing namespace. Only empty namespaces (no tables) can be removed.
+   * @param name namespace name
+   */
+  CompletableFuture<Void> deleteNamespace(final String name);
+
+  /**
+   * Get a namespace descriptor by name
+   * @param name name of namespace descriptor
+   * @return A descriptor wrapped by a {@link CompletableFuture}.
+   */
+  CompletableFuture<NamespaceDescriptor> getNamespaceDescriptor(final String name);
+
+  /**
+   * List available namespace descriptors
+   * @return List of descriptors wrapped by a {@link CompletableFuture}.
+   */
+  CompletableFuture<NamespaceDescriptor[]> listNamespaceDescriptors();
+
   /**
    * Turn the load balancer on or off.
    * @param on

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncHBaseAdmin.java

@@ -38,6 +38,7 @@ import org.apache.hadoop.hbase.MetaTableAccessor;
 import org.apache.hadoop.hbase.NotServingRegionException;
 import org.apache.hadoop.hbase.RegionLocations;
 import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.NamespaceDescriptor;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.AsyncMetaTableAccessor;
 import org.apache.hadoop.hbase.HConstants;
@@ -60,12 +61,18 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.AddColumnR
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.AddColumnResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.BalanceRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.BalanceResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.CreateNamespaceRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.CreateNamespaceResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteNamespaceRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteNamespaceResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DisableTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DisableTableResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.EnableTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.EnableTableResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteColumnRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteColumnResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetNamespaceDescriptorRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetNamespaceDescriptorResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetProcedureResultRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetProcedureResultResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetSchemaAlterStatusRequest;
@@ -80,9 +87,13 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteTabl
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteTableResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.IsBalancerEnabledRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.IsBalancerEnabledResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListNamespaceDescriptorsRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListNamespaceDescriptorsResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.MasterService;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ModifyColumnRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ModifyColumnResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ModifyNamespaceRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ModifyNamespaceResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.SetBalancerRunningRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.SetBalancerRunningResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.TruncateTableRequest;
@@ -208,7 +219,7 @@ public class AsyncHBaseAdmin implements AsyncAdmin {
 
   private <PREQ, PRESP> CompletableFuture<Void> procedureCall(PREQ preq,
       MasterRpcCall<PRESP, PREQ> rpcCall, Converter<Long, PRESP> respConverter,
-      TableProcedureBiConsumer consumer) {
+      ProcedureBiConsumer consumer) {
     CompletableFuture<Long> procFuture = this
         .<Long> newMasterCaller()
         .action(
@@ -467,6 +478,54 @@ public class AsyncHBaseAdmin implements AsyncAdmin {
       (resp) -> resp.getProcId(), new ModifyColumnFamilyProcedureBiConsumer(this, tableName));
   }
 
+  @Override
+  public CompletableFuture<Void> createNamespace(NamespaceDescriptor descriptor) {
+    return this.<CreateNamespaceRequest, CreateNamespaceResponse> procedureCall(
+      RequestConverter.buildCreateNamespaceRequest(descriptor),
+      (s, c, req, done) -> s.createNamespace(c, req, done), (resp) -> resp.getProcId(),
+      new CreateNamespaceProcedureBiConsumer(this, descriptor.getName()));
+  }
+
+  @Override
+  public CompletableFuture<Void> modifyNamespace(NamespaceDescriptor descriptor) {
+    return this.<ModifyNamespaceRequest, ModifyNamespaceResponse> procedureCall(
+      RequestConverter.buildModifyNamespaceRequest(descriptor),
+      (s, c, req, done) -> s.modifyNamespace(c, req, done), (resp) -> resp.getProcId(),
+      new ModifyNamespaceProcedureBiConsumer(this, descriptor.getName()));
+  }
+
+  @Override
+  public CompletableFuture<Void> deleteNamespace(String name) {
+    return this.<DeleteNamespaceRequest, DeleteNamespaceResponse> procedureCall(
+      RequestConverter.buildDeleteNamespaceRequest(name),
+      (s, c, req, done) -> s.deleteNamespace(c, req, done), (resp) -> resp.getProcId(),
+      new ModifyNamespaceProcedureBiConsumer(this, name));
+  }
+
+  @Override
+  public CompletableFuture<NamespaceDescriptor> getNamespaceDescriptor(String name) {
+    return this
+        .<NamespaceDescriptor> newMasterCaller()
+        .action(
+          (controller, stub) -> this
+              .<GetNamespaceDescriptorRequest, GetNamespaceDescriptorResponse, NamespaceDescriptor> call(
+                controller, stub, RequestConverter.buildGetNamespaceDescriptorRequest(name), (s, c,
+                    req, done) -> s.getNamespaceDescriptor(c, req, done), (resp) -> ProtobufUtil
+                    .toNamespaceDescriptor(resp.getNamespaceDescriptor()))).call();
+  }
+
+  @Override
+  public CompletableFuture<NamespaceDescriptor[]> listNamespaceDescriptors() {
+    return this
+        .<NamespaceDescriptor[]> newMasterCaller()
+        .action(
+          (controller, stub) -> this
+              .<ListNamespaceDescriptorsRequest, ListNamespaceDescriptorsResponse, NamespaceDescriptor[]> call(
+                controller, stub, ListNamespaceDescriptorsRequest.newBuilder().build(), (s, c, req,
+                    done) -> s.listNamespaceDescriptors(c, req, done), (resp) -> ProtobufUtil
+                    .getNamespaceDescriptorArray(resp))).call();
+  }
+
   @Override
   public CompletableFuture<Boolean> setBalancerRunning(final boolean on) {
     return this
@@ -674,6 +733,31 @@ public class AsyncHBaseAdmin implements AsyncAdmin {
     }
   }
 
+  private abstract class NamespaceProcedureBiConsumer extends ProcedureBiConsumer {
+    protected final String namespaceName;
+
+    NamespaceProcedureBiConsumer(final AsyncAdmin admin, final String namespaceName) {
+      super(admin);
+      this.namespaceName = namespaceName;
+    }
+
+    abstract String getOperationType();
+
+    String getDescription() {
+      return "Operation: " + getOperationType() + ", Namespace: " + namespaceName;
+    }
+
+    @Override
+    void onFinished() {
+      LOG.info(getDescription() + " completed");
+    }
+
+    @Override
+    void onError(Throwable error) {
+      LOG.info(getDescription() + " failed with " + error.getMessage());
+    }
+  }
+
   private class CreateTableProcedureBiConsumer extends TableProcedureBiConsumer {
 
     CreateTableProcedureBiConsumer(AsyncAdmin admin, TableName tableName) {
@@ -768,6 +852,39 @@ public class AsyncHBaseAdmin implements AsyncAdmin {
     }
   }
 
+  private class CreateNamespaceProcedureBiConsumer extends NamespaceProcedureBiConsumer {
+
+    CreateNamespaceProcedureBiConsumer(AsyncAdmin admin, String namespaceName) {
+      super(admin, namespaceName);
+    }
+
+    String getOperationType() {
+      return "CREATE_NAMESPACE";
+    }
+  }
+
+  private class DeleteNamespaceProcedureBiConsumer extends NamespaceProcedureBiConsumer {
+
+    DeleteNamespaceProcedureBiConsumer(AsyncAdmin admin, String namespaceName) {
+      super(admin, namespaceName);
+    }
+
+    String getOperationType() {
+      return "DELETE_NAMESPACE";
+    }
+  }
+
+  private class ModifyNamespaceProcedureBiConsumer extends NamespaceProcedureBiConsumer {
+
+    ModifyNamespaceProcedureBiConsumer(AsyncAdmin admin, String namespaceName) {
+      super(admin, namespaceName);
+    }
+
+    String getOperationType() {
+      return "MODIFY_NAMESPACE";
+    }
+  }
+
   private CompletableFuture<Void> waitProcedureResult(CompletableFuture<Long> procFuture) {
     CompletableFuture<Void> future = new CompletableFuture<>();
     procFuture.whenComplete((procId, error) -> {

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncRpcRetryingCaller.java

@@ -114,6 +114,10 @@ public abstract class AsyncRpcRetryingCaller<T> {
   protected void onError(Throwable error, Supplier<String> errMsg,
       Consumer<Throwable> updateCachedLocation) {
     error = translateException(error);
+    if (error instanceof DoNotRetryIOException) {
+      future.completeExceptionally(error);
+      return;
+    }
     if (tries > startLogErrorsCnt) {
       LOG.warn(errMsg.get() + ", tries = " + tries + ", maxAttempts = " + maxAttempts
           + ", timeout = " + TimeUnit.NANOSECONDS.toMillis(operationTimeoutNs)
@@ -122,7 +126,7 @@ public abstract class AsyncRpcRetryingCaller<T> {
     RetriesExhaustedException.ThrowableWithExtraContext qt = new RetriesExhaustedException.ThrowableWithExtraContext(
         error, EnvironmentEdgeManager.currentTime(), "");
     exceptions.add(qt);
-    if (error instanceof DoNotRetryIOException || tries >= maxAttempts) {
+    if (tries >= maxAttempts) {
       completeExceptionally();
       return;
     }

hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java

@@ -151,6 +151,8 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MapReduceProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.CreateTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableDescriptorsResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListNamespaceDescriptorsRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListNamespaceDescriptorsResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionServerReportRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionServerStartupRequest;
@@ -393,6 +395,21 @@ public final class ProtobufUtil {
     return ServerName.valueOf(hostName, port, startCode);
   }
 
+  /**
+   * Get NamespaceDescriptor[] from ListNamespaceDescriptorsResponse protobuf
+   * @param proto the ListNamespaceDescriptorsResponse
+   * @return NamespaceDescriptor[]
+   */
+  public static NamespaceDescriptor[] getNamespaceDescriptorArray(
+      ListNamespaceDescriptorsResponse proto) {
+    List<HBaseProtos.NamespaceDescriptor> list = proto.getNamespaceDescriptorList();
+    NamespaceDescriptor[] res = new NamespaceDescriptor[list.size()];
+    for (int i = 0; i < list.size(); i++) {
+      res[i] = ProtobufUtil.toNamespaceDescriptor(list.get(i));
+    }
+    return res;
+  }
+
   /**
    * Get HTableDescriptor[] from GetTableDescriptorsResponse protobuf
    *
@@ -2136,10 +2153,8 @@ public final class ProtobufUtil {
     return b.build();
   }
 
-  public static NamespaceDescriptor toNamespaceDescriptor(
-      HBaseProtos.NamespaceDescriptor desc) throws IOException {
-    NamespaceDescriptor.Builder b =
-      NamespaceDescriptor.create(desc.getName().toStringUtf8());
+  public static NamespaceDescriptor toNamespaceDescriptor(HBaseProtos.NamespaceDescriptor desc) {
+    NamespaceDescriptor.Builder b = NamespaceDescriptor.create(desc.getName().toStringUtf8());
     for (HBaseProtos.NameStringPair prop : desc.getConfigurationList()) {
       b.addConfiguration(prop.getName(), prop.getValue());
     }

hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java

@@ -28,6 +28,7 @@ import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.NamespaceDescriptor;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
@@ -80,11 +81,15 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.AddColumnRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.AssignRegionRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.BalanceRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.CreateNamespaceRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.CreateTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteColumnRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteNamespaceRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DeleteTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DisableTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.EnableCatalogJanitorRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetNamespaceDescriptorRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ModifyNamespaceRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.SetCleanerChoreRunningRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.EnableTableRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetClusterStatusRequest;
@@ -1644,4 +1649,50 @@ public final class RequestConverter {
     }
     return builder.build();
   }
+
+  /**
+   * Creates a protocol buffer CreateNamespaceRequest
+   * @param descriptor
+   * @return a CreateNamespaceRequest
+   */
+  public static CreateNamespaceRequest buildCreateNamespaceRequest(
+      final NamespaceDescriptor descriptor) {
+    CreateNamespaceRequest.Builder builder = CreateNamespaceRequest.newBuilder();
+    builder.setNamespaceDescriptor(ProtobufUtil.toProtoNamespaceDescriptor(descriptor));
+    return builder.build();
+  }
+
+  /**
+   * Creates a protocol buffer ModifyNamespaceRequest
+   * @param descriptor
+   * @return a ModifyNamespaceRequest
+   */
+  public static ModifyNamespaceRequest buildModifyNamespaceRequest(
+      final NamespaceDescriptor descriptor) {
+    ModifyNamespaceRequest.Builder builder = ModifyNamespaceRequest.newBuilder();
+    builder.setNamespaceDescriptor(ProtobufUtil.toProtoNamespaceDescriptor(descriptor));
+    return builder.build();
+  }
+
+  /**
+   * Creates a protocol buffer DeleteNamespaceRequest
+   * @param name
+   * @return a DeleteNamespaceRequest
+   */
+  public static DeleteNamespaceRequest buildDeleteNamespaceRequest(final String name) {
+    DeleteNamespaceRequest.Builder builder = DeleteNamespaceRequest.newBuilder();
+    builder.setNamespaceName(name);
+    return builder.build();
+  }
+
+  /**
+   * Creates a protocol buffer GetNamespaceDescriptorRequest
+   * @param name
+   * @return a GetNamespaceDescriptorRequest
+   */
+  public static GetNamespaceDescriptorRequest buildGetNamespaceDescriptorRequest(final String name) {
+    GetNamespaceDescriptorRequest.Builder builder = GetNamespaceDescriptorRequest.newBuilder();
+    builder.setNamespaceName(name);
+    return builder.build();
+  }
 }

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

@@ -0,0 +1,67 @@
+/**
+ * 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.apache.hadoop.hbase.client.AsyncProcess.START_LOG_ERRORS_AFTER_COUNT_KEY;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+
+/**
+ * Class to test AsyncAdmin.
+ */
+public abstract class TestAsyncAdminBase {
+
+  protected static final Log LOG = LogFactory.getLog(TestAdmin1.class);
+  protected final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
+  protected static byte[] FAMILY = Bytes.toBytes("testFamily");
+  protected static final byte[] FAMILY_0 = Bytes.toBytes("cf0");
+  protected static final byte[] FAMILY_1 = Bytes.toBytes("cf1");
+
+  protected static AsyncConnection ASYNC_CONN;
+  protected AsyncAdmin admin;
+
+  @BeforeClass
+  public static void setUpBeforeClass() throws Exception {
+    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_PAUSE, 10);
+    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 3);
+    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_RPC_TIMEOUT_KEY, 1000);
+    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_OPERATION_TIMEOUT, 3000);
+    TEST_UTIL.getConfiguration().setInt(START_LOG_ERRORS_AFTER_COUNT_KEY, 0);
+    TEST_UTIL.startMiniCluster(1);
+    ASYNC_CONN = ConnectionFactory.createAsyncConnection(TEST_UTIL.getConfiguration()).get();
+  }
+
+  @AfterClass
+  public static void tearDownAfterClass() throws Exception {
+    IOUtils.closeQuietly(ASYNC_CONN);
+    TEST_UTIL.shutdownMiniCluster();
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    this.admin = ASYNC_CONN.getAdmin();
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncBalancerAdminApi.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.client;
+
+import static org.junit.Assert.assertEquals;
+
+import org.apache.hadoop.hbase.testclassification.ClientTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({ MediumTests.class, ClientTests.class })
+public class TestAsyncBalancerAdminApi extends TestAsyncAdminBase {
+
+  @Test
+  public void testBalancer() throws Exception {
+    boolean initialState = admin.isBalancerEnabled().get();
+
+    // Start the balancer, wait for it.
+    boolean prevState = admin.setBalancerRunning(!initialState).get();
+
+    // The previous state should be the original state we observed
+    assertEquals(initialState, prevState);
+
+    // Current state should be opposite of the original
+    assertEquals(!initialState, admin.isBalancerEnabled().get());
+
+    // Reset it back to what it was
+    prevState = admin.setBalancerRunning(initialState).get();
+
+    // The previous state should be the opposite of the initial state
+    assertEquals(!initialState, prevState);
+    // Current state should be the original state again
+    assertEquals(initialState, admin.isBalancerEnabled().get());
+  }
+}

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

@@ -0,0 +1,189 @@
+/**
+ * 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.apache.hadoop.hbase.client.AsyncProcess.START_LOG_ERRORS_AFTER_COUNT_KEY;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.util.concurrent.Callable;
+
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.MiniHBaseCluster;
+import org.apache.hadoop.hbase.NamespaceDescriptor;
+import org.apache.hadoop.hbase.NamespaceExistException;
+import org.apache.hadoop.hbase.NamespaceNotFoundException;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.Waiter;
+import org.apache.hadoop.hbase.ZKNamespaceManager;
+import org.apache.hadoop.hbase.master.HMaster;
+import org.apache.hadoop.hbase.testclassification.ClientTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+/**
+ * Class to test asynchronous namespace admin operations.
+ */
+@Category({ MediumTests.class, ClientTests.class })
+public class TestAsyncNamespaceAdminApi extends TestAsyncAdminBase {
+
+  private String prefix = "TestNamespace";
+  private static HMaster master;
+  private static ZKNamespaceManager zkNamespaceManager;
+
+  @BeforeClass
+  public static void setUpBeforeClass() throws Exception {
+    TEST_UTIL.getConfiguration().setInt(START_LOG_ERRORS_AFTER_COUNT_KEY, 0);
+    TEST_UTIL.startMiniCluster(1);
+    ASYNC_CONN = ConnectionFactory.createAsyncConnection(TEST_UTIL.getConfiguration()).get();
+    master = ((MiniHBaseCluster) TEST_UTIL.getHBaseCluster()).getMaster();
+    zkNamespaceManager = new ZKNamespaceManager(master.getZooKeeper());
+    zkNamespaceManager.start();
+    LOG.info("Done initializing cluster");
+  }
+
+  @Test(timeout = 60000)
+  public void testCreateAndDelete() throws Exception {
+    String testName = "testCreateAndDelete";
+    String nsName = prefix + "_" + testName;
+
+    // create namespace and verify
+    admin.createNamespace(NamespaceDescriptor.create(nsName).build()).join();
+    assertEquals(3, admin.listNamespaceDescriptors().get().length);
+    TEST_UTIL.waitFor(60000, new Waiter.Predicate<Exception>() {
+      @Override
+      public boolean evaluate() throws Exception {
+        return zkNamespaceManager.list().size() == 3;
+      }
+    });
+    assertNotNull(zkNamespaceManager.get(nsName));
+    // delete namespace and verify
+    admin.deleteNamespace(nsName).join();
+    assertEquals(2, admin.listNamespaceDescriptors().get().length);
+    assertEquals(2, zkNamespaceManager.list().size());
+    assertNull(zkNamespaceManager.get(nsName));
+  }
+
+  @Test(timeout = 60000)
+  public void testDeleteReservedNS() throws Exception {
+    boolean exceptionCaught = false;
+    try {
+      admin.deleteNamespace(NamespaceDescriptor.DEFAULT_NAMESPACE_NAME_STR).join();
+    } catch (Exception exp) {
+      LOG.warn(exp);
+      exceptionCaught = true;
+    } finally {
+      assertTrue(exceptionCaught);
+    }
+
+    try {
+      admin.deleteNamespace(NamespaceDescriptor.SYSTEM_NAMESPACE_NAME_STR).join();
+    } catch (Exception exp) {
+      LOG.warn(exp);
+      exceptionCaught = true;
+    } finally {
+      assertTrue(exceptionCaught);
+    }
+  }
+
+  @Test(timeout = 60000)
+  public void testNamespaceOperations() throws Exception {
+    admin.createNamespace(NamespaceDescriptor.create(prefix + "ns1").build()).join();
+    admin.createNamespace(NamespaceDescriptor.create(prefix + "ns2").build()).join();
+
+    // create namespace that already exists
+    runWithExpectedException(new Callable<Void>() {
+      @Override
+      public Void call() throws Exception {
+        admin.createNamespace(NamespaceDescriptor.create(prefix + "ns1").build()).join();
+        return null;
+      }
+    }, NamespaceExistException.class);
+
+    // create a table in non-existing namespace
+    runWithExpectedException(new Callable<Void>() {
+      @Override
+      public Void call() throws Exception {
+        HTableDescriptor htd = new HTableDescriptor(TableName.valueOf("non_existing_namespace",
+          "table1"));
+        htd.addFamily(new HColumnDescriptor("family1"));
+        admin.createTable(htd).join();
+        return null;
+      }
+    }, NamespaceNotFoundException.class);
+
+    // get descriptor for existing namespace
+    NamespaceDescriptor ns1 = admin.getNamespaceDescriptor(prefix + "ns1").get();
+    assertEquals(prefix + "ns1", ns1.getName());
+
+    // get descriptor for non-existing namespace
+    runWithExpectedException(new Callable<NamespaceDescriptor>() {
+      @Override
+      public NamespaceDescriptor call() throws Exception {
+        return admin.getNamespaceDescriptor("non_existing_namespace").get();
+      }
+    }, NamespaceNotFoundException.class);
+
+    // delete descriptor for existing namespace
+    admin.deleteNamespace(prefix + "ns2").join();
+
+    // delete descriptor for non-existing namespace
+    runWithExpectedException(new Callable<Void>() {
+      @Override
+      public Void call() throws Exception {
+        admin.deleteNamespace("non_existing_namespace").join();
+        return null;
+      }
+    }, NamespaceNotFoundException.class);
+
+    // modify namespace descriptor for existing namespace
+    ns1 = admin.getNamespaceDescriptor(prefix + "ns1").get();
+    ns1.setConfiguration("foo", "bar");
+    admin.modifyNamespace(ns1).join();
+    ns1 = admin.getNamespaceDescriptor(prefix + "ns1").get();
+    assertEquals("bar", ns1.getConfigurationValue("foo"));
+
+    // modify namespace descriptor for non-existing namespace
+    runWithExpectedException(new Callable<Void>() {
+      @Override
+      public Void call() throws Exception {
+        admin.modifyNamespace(NamespaceDescriptor.create("non_existing_namespace").build()).join();
+        return null;
+      }
+    }, NamespaceNotFoundException.class);
+
+    admin.deleteNamespace(prefix + "ns1").join();
+  }
+
+  private static <V, E> void runWithExpectedException(Callable<V> callable, Class<E> exceptionClass) {
+    try {
+      callable.call();
+    } catch (Exception ex) {
+      LOG.info("Get exception is " + ex);
+      assertEquals(exceptionClass, ex.getCause().getClass());
+      return;
+    }
+    fail("Should have thrown exception " + exceptionClass);
+  }
+}

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

@@ -0,0 +1,203 @@
+/**
+ * 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.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.util.List;
+
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionInfo;
+import org.apache.hadoop.hbase.HRegionLocation;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.regionserver.HRegionServer;
+import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
+import org.apache.hadoop.hbase.testclassification.ClientTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.Pair;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+/**
+ * Class to test asynchronous region admin operations.
+ */
+@Category({ MediumTests.class, ClientTests.class })
+public class TestAsyncRegionAdminApi extends TestAsyncAdminBase {
+
+  private void createTableWithDefaultConf(TableName TABLENAME) throws Exception {
+    HTableDescriptor htd = new HTableDescriptor(TABLENAME);
+    HColumnDescriptor hcd = new HColumnDescriptor("value");
+    htd.addFamily(hcd);
+
+    admin.createTable(htd, null).get();
+  }
+
+  @Test
+  public void testCloseRegion() throws Exception {
+    TableName TABLENAME = TableName.valueOf("TestHBACloseRegion");
+    createTableWithDefaultConf(TABLENAME);
+
+    HRegionInfo info = null;
+    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TABLENAME);
+    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+    for (HRegionInfo regionInfo : onlineRegions) {
+      if (!regionInfo.getTable().isSystemTable()) {
+        info = regionInfo;
+        boolean closed = admin.closeRegionWithEncodedRegionName(regionInfo.getEncodedName(),
+          rs.getServerName().getServerName()).get();
+        assertTrue(closed);
+      }
+    }
+    boolean isInList = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices()).contains(info);
+    long timeout = System.currentTimeMillis() + 10000;
+    while ((System.currentTimeMillis() < timeout) && (isInList)) {
+      Thread.sleep(100);
+      isInList = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices()).contains(info);
+    }
+
+    assertFalse("The region should not be present in online regions list.", isInList);
+  }
+
+  @Test
+  public void testCloseRegionIfInvalidRegionNameIsPassed() throws Exception {
+    final String name = "TestHBACloseRegion1";
+    byte[] TABLENAME = Bytes.toBytes(name);
+    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
+
+    HRegionInfo info = null;
+    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
+    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+    for (HRegionInfo regionInfo : onlineRegions) {
+      if (!regionInfo.isMetaTable()) {
+        if (regionInfo.getRegionNameAsString().contains(name)) {
+          info = regionInfo;
+          boolean catchNotServingException = false;
+          try {
+            admin.closeRegionWithEncodedRegionName("sample", rs.getServerName().getServerName())
+                .get();
+          } catch (Exception e) {
+            catchNotServingException = true;
+            // expected, ignore it
+          }
+          assertTrue(catchNotServingException);
+        }
+      }
+    }
+    onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+    assertTrue("The region should be present in online regions list.",
+      onlineRegions.contains(info));
+  }
+
+  @Test
+  public void testCloseRegionWhenServerNameIsNull() throws Exception {
+    byte[] TABLENAME = Bytes.toBytes("TestHBACloseRegion3");
+    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
+
+    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
+
+    try {
+      List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+      for (HRegionInfo regionInfo : onlineRegions) {
+        if (!regionInfo.isMetaTable()) {
+          if (regionInfo.getRegionNameAsString().contains("TestHBACloseRegion3")) {
+            admin.closeRegionWithEncodedRegionName(regionInfo.getEncodedName(), null).get();
+          }
+        }
+      }
+      fail("The test should throw exception if the servername passed is null.");
+    } catch (IllegalArgumentException e) {
+    }
+  }
+
+  @Test
+  public void testCloseRegionWhenServerNameIsEmpty() throws Exception {
+    byte[] TABLENAME = Bytes.toBytes("TestHBACloseRegionWhenServerNameIsEmpty");
+    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
+
+    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
+
+    try {
+      List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+      for (HRegionInfo regionInfo : onlineRegions) {
+        if (!regionInfo.isMetaTable()) {
+          if (regionInfo.getRegionNameAsString()
+              .contains("TestHBACloseRegionWhenServerNameIsEmpty")) {
+            admin.closeRegionWithEncodedRegionName(regionInfo.getEncodedName(), " ").get();
+          }
+        }
+      }
+      fail("The test should throw exception if the servername passed is empty.");
+    } catch (IllegalArgumentException e) {
+    }
+  }
+
+  @Test
+  public void testCloseRegionWhenEncodedRegionNameIsNotGiven() throws Exception {
+    byte[] TABLENAME = Bytes.toBytes("TestHBACloseRegion4");
+    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
+
+    HRegionInfo info = null;
+    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
+
+    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+    for (HRegionInfo regionInfo : onlineRegions) {
+      if (!regionInfo.isMetaTable()) {
+        if (regionInfo.getRegionNameAsString().contains("TestHBACloseRegion4")) {
+          info = regionInfo;
+          boolean catchNotServingException = false;
+          try {
+            admin.closeRegionWithEncodedRegionName(regionInfo.getRegionNameAsString(),
+              rs.getServerName().getServerName()).get();
+          } catch (Exception e) {
+            // expected, ignore it.
+            catchNotServingException = true;
+          }
+          assertTrue(catchNotServingException);
+        }
+      }
+    }
+    onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
+    assertTrue("The region should be present in online regions list.",
+      onlineRegions.contains(info));
+  }
+
+  @Test
+  public void testGetRegion() throws Exception {
+    AsyncHBaseAdmin rawAdmin = (AsyncHBaseAdmin) admin;
+
+    final TableName tableName = TableName.valueOf("testGetRegion");
+    LOG.info("Started " + tableName);
+    TEST_UTIL.createMultiRegionTable(tableName, HConstants.CATALOG_FAMILY);
+
+    try (RegionLocator locator = TEST_UTIL.getConnection().getRegionLocator(tableName)) {
+      HRegionLocation regionLocation = locator.getRegionLocation(Bytes.toBytes("mmm"));
+      HRegionInfo region = regionLocation.getRegionInfo();
+      byte[] regionName = region.getRegionName();
+      Pair<HRegionInfo, ServerName> pair = rawAdmin.getRegion(regionName).get();
+      assertTrue(Bytes.equals(regionName, pair.getFirst().getRegionName()));
+      pair = rawAdmin.getRegion(region.getEncodedNameAsBytes()).get();
+      assertTrue(Bytes.equals(regionName, pair.getFirst().getRegionName()));
+    }
+  }
+}

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

@@ -17,11 +17,9 @@
  */
 package org.apache.hadoop.hbase.client;
 
-import static org.apache.hadoop.hbase.client.AsyncProcess.START_LOG_ERRORS_AFTER_COUNT_KEY;
-import static org.apache.hadoop.hbase.TableName.META_TABLE_NAME;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.IOException;
@@ -36,12 +34,8 @@ import java.util.Set;
 import java.util.concurrent.CompletionException;
 import java.util.regex.Pattern;
 
-import org.apache.commons.io.IOUtils;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.AsyncMetaTableAccessor;
-import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HRegionInfo;
@@ -51,63 +45,26 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.TableNotEnabledException;
 import org.apache.hadoop.hbase.master.MasterFileSystem;
-import org.apache.hadoop.hbase.regionserver.HRegionServer;
-import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
 import org.apache.hadoop.hbase.testclassification.LargeTests;
 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.Pair;
-import org.junit.AfterClass;
 import org.junit.Assert;
-import org.junit.Before;
-import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import org.junit.rules.TestName;
 
 /**
- * Class to test AsyncAdmin.
+ * Class to test asynchronous table admin operations.
  */
 @Category({LargeTests.class, ClientTests.class})
-public class TestAsyncAdmin {
-
-  private static final Log LOG = LogFactory.getLog(TestAdmin1.class);
-  private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
-  private static byte[] FAMILY = Bytes.toBytes("testFamily");
-  private static final byte[] FAMILY_0 = Bytes.toBytes("cf0");
-  private static final byte[] FAMILY_1 = Bytes.toBytes("cf1");
-
-  private static AsyncConnection ASYNC_CONN;
-  private AsyncAdmin admin;
+public class TestAsyncTableAdminApi extends TestAsyncAdminBase {
 
   @Rule
   public TestName name = new TestName();
 
-  @BeforeClass
-  public static void setUpBeforeClass() throws Exception {
-    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_PAUSE, 10);
-    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 3);
-    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_RPC_TIMEOUT_KEY, 1000);
-    TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_OPERATION_TIMEOUT, 3000);
-    TEST_UTIL.getConfiguration().setInt(START_LOG_ERRORS_AFTER_COUNT_KEY, 0);
-    TEST_UTIL.startMiniCluster(1);
-    ASYNC_CONN = ConnectionFactory.createAsyncConnection(TEST_UTIL.getConfiguration()).get();
-  }
-
-  @AfterClass
-  public static void tearDownAfterClass() throws Exception {
-    IOUtils.closeQuietly(ASYNC_CONN);
-    TEST_UTIL.shutdownMiniCluster();
-  }
-
-  @Before
-  public void setUp() throws Exception {
-    this.admin = ASYNC_CONN.getAdmin();
-  }
-
   @Test
   public void testTableExist() throws Exception {
     final TableName tableName = TableName.valueOf(name.getMethodName());
@@ -200,7 +157,7 @@ public class TestAsyncAdmin {
 
   private TableState.State getStateFromMeta(TableName table) throws Exception {
     Optional<TableState> state = AsyncMetaTableAccessor.getTableState(
-      ASYNC_CONN.getRawTable(META_TABLE_NAME), table).get();
+      ASYNC_CONN.getRawTable(TableName.META_TABLE_NAME), table).get();
     assertTrue(state.isPresent());
     return state.get().getState();
   }
@@ -878,210 +835,4 @@ public class TestAsyncAdmin {
     }
   }
 
-  @Test(timeout = 30000)
-  public void testBalancer() throws Exception {
-    boolean initialState = admin.isBalancerEnabled().get();
-
-    // Start the balancer, wait for it.
-    boolean prevState = admin.setBalancerRunning(!initialState).get();
-
-    // The previous state should be the original state we observed
-    assertEquals(initialState, prevState);
-
-    // Current state should be opposite of the original
-    assertEquals(!initialState, admin.isBalancerEnabled().get());
-
-    // Reset it back to what it was
-    prevState = admin.setBalancerRunning(initialState).get();
-
-    // The previous state should be the opposite of the initial state
-    assertEquals(!initialState, prevState);
-    // Current state should be the original state again
-    assertEquals(initialState, admin.isBalancerEnabled().get());
-  }
-
-  private void createTableWithDefaultConf(TableName TABLENAME) throws Exception {
-    HTableDescriptor htd = new HTableDescriptor(TABLENAME);
-    HColumnDescriptor hcd = new HColumnDescriptor("value");
-    htd.addFamily(hcd);
-
-    admin.createTable(htd, null).get();
-  }
-
-  @Test
-  public void testCloseRegion() throws Exception {
-    TableName TABLENAME = TableName.valueOf("TestHBACloseRegion");
-    createTableWithDefaultConf(TABLENAME);
-
-    HRegionInfo info = null;
-    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TABLENAME);
-    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-    for (HRegionInfo regionInfo : onlineRegions) {
-      if (!regionInfo.getTable().isSystemTable()) {
-        info = regionInfo;
-        boolean closed = admin.closeRegionWithEncodedRegionName(regionInfo.getEncodedName(),
-          rs.getServerName().getServerName()).get();
-        assertTrue(closed);
-      }
-    }
-    boolean isInList = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices()).contains(info);
-    long timeout = System.currentTimeMillis() + 10000;
-    while ((System.currentTimeMillis() < timeout) && (isInList)) {
-      Thread.sleep(100);
-      isInList = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices()).contains(info);
-    }
-
-    assertFalse("The region should not be present in online regions list.", isInList);
-  }
-
-  @Test
-  public void testCloseRegionIfInvalidRegionNameIsPassed() throws Exception {
-    final String name = "TestHBACloseRegion1";
-    byte[] TABLENAME = Bytes.toBytes(name);
-    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
-
-    HRegionInfo info = null;
-    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
-    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-    for (HRegionInfo regionInfo : onlineRegions) {
-      if (!regionInfo.isMetaTable()) {
-        if (regionInfo.getRegionNameAsString().contains(name)) {
-          info = regionInfo;
-          boolean catchNotServingException = false;
-          try {
-            admin.closeRegionWithEncodedRegionName("sample", rs.getServerName().getServerName())
-                .get();
-          } catch (Exception e) {
-            catchNotServingException = true;
-            // expected, ignore it
-          }
-          assertTrue(catchNotServingException);
-        }
-      }
-    }
-    onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-    assertTrue("The region should be present in online regions list.",
-      onlineRegions.contains(info));
-  }
-
-  @Test
-  public void testCloseRegionThatFetchesTheHRIFromMeta() throws Exception {
-    TableName TABLENAME = TableName.valueOf("TestHBACloseRegion2");
-    createTableWithDefaultConf(TABLENAME);
-
-    HRegionInfo info = null;
-    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TABLENAME);
-    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-    for (HRegionInfo regionInfo : onlineRegions) {
-      if (!regionInfo.isMetaTable()) {
-
-        if (regionInfo.getRegionNameAsString().contains("TestHBACloseRegion2")) {
-          info = regionInfo;
-          admin.closeRegion(regionInfo.getRegionNameAsString(), rs.getServerName().getServerName())
-              .get();
-        }
-      }
-    }
-
-    boolean isInList = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices()).contains(info);
-    long timeout = System.currentTimeMillis() + 10000;
-    while ((System.currentTimeMillis() < timeout) && (isInList)) {
-      Thread.sleep(100);
-      isInList = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices()).contains(info);
-    }
-
-    assertFalse("The region should not be present in online regions list.", isInList);
-  }
-
-  @Test
-  public void testCloseRegionWhenServerNameIsNull() throws Exception {
-    byte[] TABLENAME = Bytes.toBytes("TestHBACloseRegion3");
-    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
-
-    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
-
-    try {
-      List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-      for (HRegionInfo regionInfo : onlineRegions) {
-        if (!regionInfo.isMetaTable()) {
-          if (regionInfo.getRegionNameAsString().contains("TestHBACloseRegion3")) {
-            admin.closeRegionWithEncodedRegionName(regionInfo.getEncodedName(), null).get();
-          }
-        }
-      }
-      fail("The test should throw exception if the servername passed is null.");
-    } catch (IllegalArgumentException e) {
-    }
-  }
-
-  @Test
-  public void testCloseRegionWhenServerNameIsEmpty() throws Exception {
-    byte[] TABLENAME = Bytes.toBytes("TestHBACloseRegionWhenServerNameIsEmpty");
-    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
-
-    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
-
-    try {
-      List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-      for (HRegionInfo regionInfo : onlineRegions) {
-        if (!regionInfo.isMetaTable()) {
-          if (regionInfo.getRegionNameAsString()
-              .contains("TestHBACloseRegionWhenServerNameIsEmpty")) {
-            admin.closeRegionWithEncodedRegionName(regionInfo.getEncodedName(), " ").get();
-          }
-        }
-      }
-      fail("The test should throw exception if the servername passed is empty.");
-    } catch (IllegalArgumentException e) {
-    }
-  }
-
-  @Test
-  public void testCloseRegionWhenEncodedRegionNameIsNotGiven() throws Exception {
-    byte[] TABLENAME = Bytes.toBytes("TestHBACloseRegion4");
-    createTableWithDefaultConf(TableName.valueOf(TABLENAME));
-
-    HRegionInfo info = null;
-    HRegionServer rs = TEST_UTIL.getRSForFirstRegionInTable(TableName.valueOf(TABLENAME));
-
-    List<HRegionInfo> onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-    for (HRegionInfo regionInfo : onlineRegions) {
-      if (!regionInfo.isMetaTable()) {
-        if (regionInfo.getRegionNameAsString().contains("TestHBACloseRegion4")) {
-          info = regionInfo;
-          boolean catchNotServingException = false;
-          try {
-            admin.closeRegionWithEncodedRegionName(regionInfo.getRegionNameAsString(),
-              rs.getServerName().getServerName()).get();
-          } catch (Exception e) {
-            // expected, ignore it.
-            catchNotServingException = true;
-          }
-          assertTrue(catchNotServingException);
-        }
-      }
-    }
-    onlineRegions = ProtobufUtil.getOnlineRegions(rs.getRSRpcServices());
-    assertTrue("The region should be present in online regions list.",
-      onlineRegions.contains(info));
-  }
-
-  @Test
-  public void testGetRegion() throws Exception {
-    AsyncHBaseAdmin rawAdmin = (AsyncHBaseAdmin) admin;
-
-    final TableName tableName = TableName.valueOf("testGetRegion");
-    LOG.info("Started " + tableName);
-    TEST_UTIL.createMultiRegionTable(tableName, HConstants.CATALOG_FAMILY);
-
-    try (RegionLocator locator = TEST_UTIL.getConnection().getRegionLocator(tableName)) {
-      HRegionLocation regionLocation = locator.getRegionLocation(Bytes.toBytes("mmm"));
-      HRegionInfo region = regionLocation.getRegionInfo();
-      byte[] regionName = region.getRegionName();
-      Pair<HRegionInfo, ServerName> pair = rawAdmin.getRegion(regionName).get();
-      assertTrue(Bytes.equals(regionName, pair.getFirst().getRegionName()));
-      pair = rawAdmin.getRegion(region.getEncodedNameAsBytes()).get();
-      assertTrue(Bytes.equals(regionName, pair.getFirst().getRegionName()));
-    }
-  }
 }