HDDS-362. Modify functions impacted by SCM chill mode in ScmBlockLocationProtocol. Contributed by Ajay Kumar.

hadoop-hdds/common/src/main/proto/hdds.proto

@@ -171,6 +171,13 @@ enum ReplicationFactor {
     THREE = 3;
 }
 
+enum ScmOps {
+    allocateBlock = 1;
+    keyBlocksInfoList = 2;
+    getScmInfo = 3;
+    deleteBlock = 4;
+}
+
 /**
  * Block ID that uniquely identify a block by SCM.
  */

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/block/BlockManagerImpl.java

@@ -18,6 +18,7 @@ package org.apache.hadoop.hdds.scm.block;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.StorageUnit;
+import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.container.Mapping;
 import org.apache.hadoop.hdds.scm.container.common.helpers.AllocatedBlock;
@@ -28,6 +29,9 @@ import org.apache.hadoop.hdds.scm.node.NodeManager;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationFactor;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationType;
+import org.apache.hadoop.hdds.scm.server.ChillModePrecheck;
+import org.apache.hadoop.hdds.scm.server.Precheck;
+import org.apache.hadoop.hdds.server.events.EventHandler;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.apache.hadoop.metrics2.util.MBeans;
 import org.apache.hadoop.hdds.client.BlockID;
@@ -61,7 +65,8 @@ import static org.apache.hadoop.ozone.OzoneConfigKeys
     .OZONE_BLOCK_DELETING_SERVICE_TIMEOUT_DEFAULT;
 
 /** Block Manager manages the block access for SCM. */
-public class BlockManagerImpl implements BlockManager, BlockmanagerMXBean {
+public class BlockManagerImpl implements EventHandler<Boolean>,
+    BlockManager, BlockmanagerMXBean {
   private static final Logger LOG =
       LoggerFactory.getLogger(BlockManagerImpl.class);
   // TODO : FIX ME : Hard coding the owner.
@@ -80,6 +85,7 @@ public class BlockManagerImpl implements BlockManager, BlockmanagerMXBean {
   private final int containerProvisionBatchSize;
   private final Random rand;
   private ObjectName mxBean;
+  private ChillModePrecheck chillModePrecheck;
 
   /**
    * Constructor.
@@ -125,6 +131,7 @@ public class BlockManagerImpl implements BlockManager, BlockmanagerMXBean {
     blockDeletingService =
         new SCMBlockDeletingService(deletedBlockLog, containerManager,
             nodeManager, eventPublisher, svcInterval, serviceTimeout, conf);
+    chillModePrecheck = new ChillModePrecheck();
   }
 
   /**
@@ -187,19 +194,13 @@ public class BlockManagerImpl implements BlockManager, BlockmanagerMXBean {
       ReplicationType type, ReplicationFactor factor, String owner)
       throws IOException {
     LOG.trace("Size;{} , type : {}, factor : {} ", size, type, factor);
-
+    preCheck(ScmOps.allocateBlock, chillModePrecheck);
     if (size < 0 || size > containerSize) {
       LOG.warn("Invalid block size requested : {}", size);
       throw new SCMException("Unsupported block size: " + size,
           INVALID_BLOCK_SIZE);
     }
 
-    if (!nodeManager.isOutOfChillMode()) {
-      LOG.warn("Not out of Chill mode.");
-      throw new SCMException("Unable to create block while in chill mode",
-          CHILL_MODE_EXCEPTION);
-    }
-
     /*
       Here is the high level logic.
 
@@ -430,4 +431,36 @@ public class BlockManagerImpl implements BlockManager, BlockmanagerMXBean {
   public SCMBlockDeletingService getSCMBlockDeletingService() {
     return this.blockDeletingService;
   }
+
+  /**
+   * Perform all prechecks for given operations.
+   *
+   * @param operation
+   * @param preChecks prechecks to be performed
+   */
+  public void preCheck(ScmOps operation, Precheck... preChecks)
+      throws SCMException {
+    for (Precheck preCheck : preChecks) {
+      preCheck.check(operation);
+    }
+  }
+
+  @Override
+  public void onMessage(Boolean inChillMode, EventPublisher publisher) {
+    this.chillModePrecheck.setInChillMode(inChillMode);
+  }
+
+  /**
+   * Returns status of scm chill mode determined by CHILL_MODE_STATUS event.
+   * */
+  public boolean isScmInChillMode() {
+    return this.chillModePrecheck.isInChillMode();
+  }
+
+  /**
+   * Get class logger.
+   * */
+  public static Logger getLogger() {
+    return LOG;
+  }
 }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/replication/ReplicationActivityStatus.java

@@ -21,7 +21,6 @@ import javax.management.ObjectName;
 import java.io.Closeable;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicBoolean;
-
 import org.apache.hadoop.hdds.server.events.EventHandler;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.apache.hadoop.metrics2.util.MBeans;
@@ -33,16 +32,22 @@ import org.slf4j.LoggerFactory;
 /**
  * Event listener to track the current state of replication.
  */
-public class ReplicationActivityStatus
+public class ReplicationActivityStatus implements
-    implements EventHandler<Boolean>, ReplicationActivityStatusMXBean,
+    ReplicationActivityStatusMXBean, Closeable {
-    Closeable {
 
   private static final Logger LOG =
       LoggerFactory.getLogger(ReplicationActivityStatus.class);
 
   private AtomicBoolean replicationEnabled = new AtomicBoolean();
-
+  private AtomicBoolean replicationStatusSetExternally = new AtomicBoolean();
   private ObjectName jmxObjectName;
+  private ReplicationStatusListener replicationStatusListener;
+  private ChillModeStatusListener chillModeStatusListener;
+
+  public ReplicationActivityStatus(){
+    replicationStatusListener = new ReplicationStatusListener();
+    chillModeStatusListener = new ChillModeStatusListener();
+  }
 
   public boolean isReplicationEnabled() {
     return replicationEnabled.get();
@@ -58,13 +63,6 @@ public class ReplicationActivityStatus
     replicationEnabled.set(true);
   }
 
-  /**
-   * The replication status could be set by async events.
-   */
-  @Override
-  public void onMessage(Boolean enabled, EventPublisher publisher) {
-    replicationEnabled.set(enabled);
-  }
 
   public void start() {
     try {
@@ -83,4 +81,37 @@ public class ReplicationActivityStatus
       MBeans.unregister(jmxObjectName);
     }
   }
+
+  /**
+   * Replication status listener.
+   */
+  class ReplicationStatusListener implements EventHandler<Boolean> {
+    @Override
+    public void onMessage(Boolean status, EventPublisher publisher) {
+      replicationStatusSetExternally.set(true);
+      replicationEnabled.set(status);
+    }
+  }
+
+  /**
+   * Replication status is influenced by Chill mode status as well.
+   */
+  class ChillModeStatusListener implements EventHandler<Boolean> {
+
+    @Override
+    public void onMessage(Boolean inChillMode, EventPublisher publisher) {
+      if (!replicationStatusSetExternally.get()) {
+        replicationEnabled.set(!inChillMode);
+      }
+    }
+  }
+
+  public ReplicationStatusListener getReplicationStatusListener() {
+    return replicationStatusListener;
+  }
+
+  public ChillModeStatusListener getChillModeStatusListener() {
+    return chillModeStatusListener;
+  }
+
 }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/events/SCMEvents.java

@@ -231,6 +231,8 @@ public final class SCMEvents {
    */
   public static final TypedEvent<Boolean> START_REPLICATION =
       new TypedEvent<>(Boolean.class);
+  public static final TypedEvent<Boolean> CHILL_MODE_STATUS =
+      new TypedEvent<>(Boolean.class);
 
   /**
    * Private Ctor. Never Constructed.

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/ChillModePrecheck.java

@@ -0,0 +1,54 @@
+/*
+ * 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.hdds.scm.server;
+
+import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
+import org.apache.hadoop.hdds.scm.exceptions.SCMException;
+import org.apache.hadoop.hdds.scm.exceptions.SCMException.ResultCodes;
+import org.apache.hadoop.hdds.scm.server.SCMChillModeManager.ChillModeRestrictedOps;
+
+/**
+ * Chill mode pre-check for SCM operations.
+ * */
+public class ChillModePrecheck implements Precheck<ScmOps> {
+
+  private boolean inChillMode;
+  public static final String PRECHECK_TYPE = "ChillModePrecheck";
+
+  public boolean check(ScmOps op) throws SCMException {
+    if(inChillMode && ChillModeRestrictedOps.isRestrictedInChillMode(op)) {
+      throw new SCMException("ChillModePrecheck failed for " + op,
+          ResultCodes.CHILL_MODE_EXCEPTION);
+    }
+    return inChillMode;
+  }
+
+  @Override
+  public String type() {
+    return PRECHECK_TYPE;
+  }
+
+  public boolean isInChillMode() {
+    return inChillMode;
+  }
+
+  public void setInChillMode(boolean inChillMode) {
+    this.inChillMode = inChillMode;
+  }
+}

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/Precheck.java

@@ -0,0 +1,29 @@
+/*
+ * 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.hdds.scm.server;
+
+import org.apache.hadoop.hdds.scm.exceptions.SCMException;
+
+/**
+ * Precheck for SCM operations.
+ * */
+public interface Precheck<T> {
+  boolean check(T t) throws SCMException;
+  String type();
+}

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/SCMChillModeManager.java

@@ -18,6 +18,7 @@
 package org.apache.hadoop.hdds.scm.server;
 
 import com.google.common.annotations.VisibleForTesting;
+import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -26,12 +27,14 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdds.HddsConfigKeys;
+import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
 import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerInfo;
 import org.apache.hadoop.hdds.scm.events.SCMEvents;
 import org.apache.hadoop.hdds.scm.server.SCMDatanodeProtocolServer
     .NodeRegistrationContainerReport;
 import org.apache.hadoop.hdds.server.events.EventHandler;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
+import org.apache.hadoop.hdds.server.events.EventQueue;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -57,16 +60,27 @@ public class SCMChillModeManager implements
   private Map<String, ChillModeExitRule> exitRules = new HashMap(1);
   private Configuration config;
   private static final String CONT_EXIT_RULE = "ContainerChillModeRule";
+  private final EventQueue eventPublisher;
 
   SCMChillModeManager(Configuration conf, List<ContainerInfo> allContainers,
-      EventPublisher eventQueue) {
+      EventQueue eventQueue) {
     this.config = conf;
+    this.eventPublisher = eventQueue;
     exitRules
         .put(CONT_EXIT_RULE, new ContainerChillModeRule(config, allContainers));
     if (!conf.getBoolean(HddsConfigKeys.HDDS_SCM_CHILLMODE_ENABLED,
         HddsConfigKeys.HDDS_SCM_CHILLMODE_ENABLED_DEFAULT)) {
       exitChillMode(eventQueue);
     }
+    emitChillModeStatus();
+  }
+
+  /**
+   * Emit Chill mode status.
+   */
+  @VisibleForTesting
+  public void emitChillModeStatus() {
+    eventPublisher.fireEvent(SCMEvents.CHILL_MODE_STATUS, inChillMode.get());
   }
 
   private void validateChillModeExitRules(EventPublisher eventQueue) {
@@ -78,11 +92,18 @@ public class SCMChillModeManager implements
     exitChillMode(eventQueue);
   }
 
-  private void exitChillMode(EventPublisher eventQueue) {
+  /**
+   * Exit chill mode. It does following actions:
+   * 1. Set chill mode status to fale.
+   * 2. Emits START_REPLICATION for ReplicationManager.
+   * 3. Cleanup resources.
+   * 4. Emit chill mode status.
+   * @param eventQueue
+   */
+  @VisibleForTesting
+  public void exitChillMode(EventPublisher eventQueue) {
     LOG.info("SCM exiting chill mode.");
     setInChillMode(false);
-    // Emit event to ReplicationManager to start replication.
-    eventQueue.fireEvent(SCMEvents.START_REPLICATION, true);
 
     // TODO: Remove handler registration as there is no need to listen to
     // register events anymore.
@@ -90,6 +111,7 @@ public class SCMChillModeManager implements
     for (ChillModeExitRule e : exitRules.values()) {
       e.cleanup();
     }
+    emitChillModeStatus();
   }
 
   @Override
@@ -106,6 +128,9 @@ public class SCMChillModeManager implements
     return inChillMode.get();
   }
 
+  /**
+   * Set chill mode status.
+   */
   public void setInChillMode(boolean inChillMode) {
     this.inChillMode.set(inChillMode);
   }
@@ -200,4 +225,20 @@ public class SCMChillModeManager implements
     return ((ContainerChillModeRule) exitRules.get(CONT_EXIT_RULE))
         .getCurrentContainerThreshold();
   }
+
+  /**
+   * Operations restricted in SCM chill mode.
+   */
+  public static class ChillModeRestrictedOps {
+    private static EnumSet restrictedOps =  EnumSet.noneOf(ScmOps.class);
+
+    static {
+      restrictedOps.add(ScmOps.allocateBlock);
+    }
+
+    public static boolean isRestrictedInChillMode(ScmOps opName) {
+      return restrictedOps.contains(opName);
+    }
+  }
+
 }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/StorageContainerManager.java

@@ -250,7 +250,10 @@ public final class StorageContainerManager extends ServiceRuntimeInfoImpl
     eventQueue.addHandler(SCMEvents.STALE_NODE, staleNodeHandler);
     eventQueue.addHandler(SCMEvents.DEAD_NODE, deadNodeHandler);
     eventQueue.addHandler(SCMEvents.CMD_STATUS_REPORT, cmdStatusReportHandler);
-    eventQueue.addHandler(SCMEvents.START_REPLICATION, replicationStatus);
+    eventQueue.addHandler(SCMEvents.START_REPLICATION,
+        replicationStatus.getReplicationStatusListener());
+    eventQueue.addHandler(SCMEvents.CHILL_MODE_STATUS,
+        replicationStatus.getChillModeStatusListener());
     eventQueue
         .addHandler(SCMEvents.PENDING_DELETE_STATUS, pendingDeleteHandler);
     eventQueue.addHandler(SCMEvents.PIPELINE_ACTIONS,
@@ -258,6 +261,8 @@ public final class StorageContainerManager extends ServiceRuntimeInfoImpl
     eventQueue.addHandler(SCMEvents.PIPELINE_CLOSE, pipelineCloseHandler);
     eventQueue.addHandler(SCMEvents.NODE_REGISTRATION_CONT_REPORT,
         scmChillModeManager);
+    eventQueue.addHandler(SCMEvents.CHILL_MODE_STATUS,
+        (BlockManagerImpl) scmBlockManager);
 
     long watcherTimeout =
         conf.getTimeDuration(ScmConfigKeys.HDDS_SCM_WATCHER_TIMEOUT,

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/block/TestBlockManager.java

@@ -17,21 +17,28 @@
 
 package org.apache.hadoop.hdds.scm.block;
 
+import java.util.UUID;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileUtil;
+import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.container.ContainerMapping;
 import org.apache.hadoop.hdds.scm.container.MockNodeManager;
 import org.apache.hadoop.hdds.scm.container.common.helpers.AllocatedBlock;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
+import org.apache.hadoop.hdds.scm.events.SCMEvents;
+import org.apache.hadoop.hdds.scm.server.SCMStorage;
+import org.apache.hadoop.hdds.scm.server.StorageContainerManager;
+import org.apache.hadoop.hdds.server.events.EventHandler;
+import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.apache.hadoop.hdds.server.events.EventQueue;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
+import org.apache.hadoop.ozone.common.Storage.StorageState;
 import org.apache.hadoop.ozone.container.common.SCMTestUtils;
 import org.apache.hadoop.test.GenericTestUtils;
-import org.junit.AfterClass;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
-import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -40,6 +47,7 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.file.Paths;
 
+import static org.apache.hadoop.ozone.OzoneConfigKeys.OZONE_ENABLED;
 import static org.apache.hadoop.ozone.OzoneConsts.GB;
 import static org.apache.hadoop.ozone.OzoneConsts.MB;
 
@@ -47,7 +55,7 @@ import static org.apache.hadoop.ozone.OzoneConsts.MB;
 /**
  * Tests for SCM Block Manager.
  */
-public class TestBlockManager {
+public class TestBlockManager implements EventHandler<Boolean> {
   private static ContainerMapping mapping;
   private static MockNodeManager nodeManager;
   private static BlockManagerImpl blockManager;
@@ -56,26 +64,30 @@ public class TestBlockManager {
   private static HddsProtos.ReplicationFactor factor;
   private static HddsProtos.ReplicationType type;
   private static String containerOwner = "OZONE";
+  private static EventQueue eventQueue;
 
   @Rule
   public ExpectedException thrown = ExpectedException.none();
-  @BeforeClass
+
-  public static void setUp() throws Exception {
+  @Before
+  public void setUp() throws Exception {
     Configuration conf = SCMTestUtils.getConf();
 
     String path = GenericTestUtils
         .getTempPath(TestBlockManager.class.getSimpleName());
-
-    conf.set(OzoneConfigKeys.OZONE_METADATA_DIRS, path);
     testDir = Paths.get(path).toFile();
+    conf.set(OzoneConfigKeys.OZONE_METADATA_DIRS, path);
+    eventQueue = new EventQueue();
     boolean folderExisted = testDir.exists() || testDir.mkdirs();
     if (!folderExisted) {
       throw new IOException("Unable to create test directory path");
     }
     nodeManager = new MockNodeManager(true, 10);
-    mapping =
+    mapping = new ContainerMapping(conf, nodeManager, 128, eventQueue);
-        new ContainerMapping(conf, nodeManager, 128, new EventQueue());
+    blockManager = new BlockManagerImpl(conf,
-    blockManager = new BlockManagerImpl(conf, nodeManager, mapping, null);
+        nodeManager, mapping, eventQueue);
+    eventQueue.addHandler(SCMEvents.CHILL_MODE_STATUS, blockManager);
+    eventQueue.addHandler(SCMEvents.START_REPLICATION, this);
     if(conf.getBoolean(ScmConfigKeys.DFS_CONTAINER_RATIS_ENABLED_KEY,
         ScmConfigKeys.DFS_CONTAINER_RATIS_ENABLED_DEFAULT)){
       factor = HddsProtos.ReplicationFactor.THREE;
@@ -86,27 +98,45 @@ public class TestBlockManager {
     }
   }
 
-  @AfterClass
+  @After
-  public static void cleanup() throws IOException {
+  public void cleanup() throws IOException {
     blockManager.close();
     mapping.close();
     FileUtil.fullyDelete(testDir);
   }
 
-  @Before
+  private static StorageContainerManager getScm(OzoneConfiguration conf)
-  public void clearChillMode() {
+      throws IOException {
-    nodeManager.setChillmode(false);
+    conf.setBoolean(OZONE_ENABLED, true);
+    SCMStorage scmStore = new SCMStorage(conf);
+    if(scmStore.getState() != StorageState.INITIALIZED) {
+      String clusterId = UUID.randomUUID().toString();
+      String scmId = UUID.randomUUID().toString();
+      scmStore.setClusterId(clusterId);
+      scmStore.setScmId(scmId);
+      // writes the version file properties
+      scmStore.initialize();
+    }
+    return StorageContainerManager.createSCM(null, conf);
   }
 
   @Test
   public void testAllocateBlock() throws Exception {
+    eventQueue.fireEvent(SCMEvents.CHILL_MODE_STATUS, false);
+    GenericTestUtils.waitFor(() -> {
+      return !blockManager.isScmInChillMode();
+    }, 10, 1000 * 5);
     AllocatedBlock block = blockManager.allocateBlock(DEFAULT_BLOCK_SIZE,
         type, factor, containerOwner);
     Assert.assertNotNull(block);
   }
 
   @Test
-  public void testAllocateOversizedBlock() throws IOException {
+  public void testAllocateOversizedBlock() throws Exception {
+    eventQueue.fireEvent(SCMEvents.CHILL_MODE_STATUS, false);
+    GenericTestUtils.waitFor(() -> {
+      return !blockManager.isScmInChillMode();
+    }, 10, 1000 * 5);
     long size = 6 * GB;
     thrown.expectMessage("Unsupported block size");
     AllocatedBlock block = blockManager.allocateBlock(size,
@@ -115,10 +145,31 @@ public class TestBlockManager {
 
 
   @Test
-  public void testChillModeAllocateBlockFails() throws IOException {
+  public void testAllocateBlockFailureInChillMode() throws Exception {
-    nodeManager.setChillmode(true);
+    eventQueue.fireEvent(SCMEvents.CHILL_MODE_STATUS, true);
-    thrown.expectMessage("Unable to create block while in chill mode");
+    GenericTestUtils.waitFor(() -> {
+      return blockManager.isScmInChillMode();
+    }, 10, 1000 * 5);
+    // Test1: In chill mode expect an SCMException.
+    thrown.expectMessage("ChillModePrecheck failed for "
+        + "allocateBlock");
     blockManager.allocateBlock(DEFAULT_BLOCK_SIZE,
         type, factor, containerOwner);
   }
+
+  @Test
+  public void testAllocateBlockSucInChillMode() throws Exception {
+    // Test2: Exit chill mode and then try allocateBock again.
+    eventQueue.fireEvent(SCMEvents.CHILL_MODE_STATUS, false);
+    GenericTestUtils.waitFor(() -> {
+      return !blockManager.isScmInChillMode();
+    }, 10, 1000 * 5);
+    Assert.assertNotNull(blockManager.allocateBlock(DEFAULT_BLOCK_SIZE,
+        type, factor, containerOwner));
+  }
+
+  @Override
+  public void onMessage(Boolean aBoolean, EventPublisher publisher) {
+    System.out.println("test");
+  }
 }

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/container/replication/TestReplicationActivityStatus.java

@@ -0,0 +1,63 @@
+/*
+ * 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.hdds.scm.container.replication;
+
+import static org.junit.Assert.*;
+
+import java.util.concurrent.TimeoutException;
+import org.apache.hadoop.hdds.scm.events.SCMEvents;
+import org.apache.hadoop.hdds.server.events.EventQueue;
+import org.apache.hadoop.test.GenericTestUtils;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+/**
+ * Tests for ReplicationActivityStatus.
+ */
+public class TestReplicationActivityStatus {
+
+  private static EventQueue eventQueue;
+  private static ReplicationActivityStatus replicationActivityStatus;
+
+  @BeforeClass
+  public static void setup() {
+    eventQueue = new EventQueue();
+    replicationActivityStatus = new ReplicationActivityStatus();
+    eventQueue.addHandler(SCMEvents.START_REPLICATION,
+        replicationActivityStatus.getReplicationStatusListener());
+    eventQueue.addHandler(SCMEvents.CHILL_MODE_STATUS,
+        replicationActivityStatus.getChillModeStatusListener());
+  }
+
+  @Test
+  public void testReplicationStatusForChillMode()
+      throws TimeoutException, InterruptedException {
+    assertFalse(replicationActivityStatus.isReplicationEnabled());
+    // In chill mode replication process should be stopped.
+    eventQueue.fireEvent(SCMEvents.CHILL_MODE_STATUS, true);
+    assertFalse(replicationActivityStatus.isReplicationEnabled());
+
+    // Replication should be enabled when chill mode if off.
+    eventQueue.fireEvent(SCMEvents.CHILL_MODE_STATUS, false);
+    GenericTestUtils.waitFor(() -> {
+      return replicationActivityStatus.isReplicationEnabled();
+    }, 10, 1000*5);
+    assertTrue(replicationActivityStatus.isReplicationEnabled());
+  }
+}