HDDS-809. Refactor SCMChillModeManager.

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

@@ -19,8 +19,8 @@
 package org.apache.hadoop.hdds.scm;
 
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
+import org.apache.hadoop.hdds.scm.chillmode.Precheck;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
-import org.apache.hadoop.hdds.scm.server.Precheck;
 
 /**
  * SCM utility class.

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

@@ -23,6 +23,7 @@ import org.apache.hadoop.hdds.client.ContainerBlockID;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
 import org.apache.hadoop.hdds.scm.ScmConfigKeys;
 import org.apache.hadoop.hdds.scm.ScmUtils;
+import org.apache.hadoop.hdds.scm.chillmode.ChillModePrecheck;
 import org.apache.hadoop.hdds.scm.container.ContainerManager;
 import org.apache.hadoop.hdds.scm.container.common.helpers.AllocatedBlock;
 import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline;
@@ -32,7 +33,6 @@ 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.server.events.EventHandler;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.apache.hadoop.metrics2.util.MBeans;

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

@@ -0,0 +1,32 @@
+/**
+ * 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.chillmode;
+
+/**
+ * Interface for defining chill mode exit rules.
+ *
+ * @param <T>
+ */
+public interface ChillModeExitRule<T> {
+
+  boolean validate();
+
+  void process(T report);
+
+  void cleanup();
+}

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

@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-package org.apache.hadoop.hdds.scm.server;
+package org.apache.hadoop.hdds.scm.chillmode;
 
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.hadoop.conf.Configuration;
@@ -24,7 +24,6 @@ import org.apache.hadoop.hdds.HddsConfigKeys;
 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.

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

@@ -0,0 +1,41 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdds.scm.chillmode;
+
+import java.util.EnumSet;
+
+import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
+
+/**
+ * Operations restricted in SCM chill mode.
+ */
+public final class ChillModeRestrictedOps {
+  private static EnumSet restrictedOps = EnumSet.noneOf(ScmOps.class);
+
+  private ChillModeRestrictedOps() {
+  }
+
+  static {
+    restrictedOps.add(ScmOps.allocateBlock);
+    restrictedOps.add(ScmOps.allocateContainer);
+  }
+
+  public static boolean isRestrictedInChillMode(ScmOps opName) {
+    return restrictedOps.contains(opName);
+  }
+}

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

@@ -0,0 +1,112 @@
+/**
+ * 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.chillmode;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+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;
+import org.apache.hadoop.hdds.scm.container.ContainerInfo;
+import org.apache.hadoop.hdds.scm.server.SCMDatanodeProtocolServer.NodeRegistrationContainerReport;
+
+import com.google.common.annotations.VisibleForTesting;
+
+/**
+ * Class defining Chill mode exit criteria for Containers.
+ */
+public class ContainerChillModeRule implements
+    ChillModeExitRule<NodeRegistrationContainerReport> {
+
+  // Required cutoff % for containers with at least 1 reported replica.
+  private double chillModeCutoff;
+  // Containers read from scm db (excluding containers in ALLOCATED state).
+  private Map<Long, ContainerInfo> containerMap;
+  private double maxContainer;
+
+  private AtomicLong containerWithMinReplicas = new AtomicLong(0);
+  private final SCMChillModeManager chillModeManager;
+
+  public ContainerChillModeRule(Configuration conf,
+      List<ContainerInfo> containers, SCMChillModeManager manager) {
+    chillModeCutoff = conf.getDouble(
+        HddsConfigKeys.HDDS_SCM_CHILLMODE_THRESHOLD_PCT,
+        HddsConfigKeys.HDDS_SCM_CHILLMODE_THRESHOLD_PCT_DEFAULT);
+    chillModeManager = manager;
+    containerMap = new ConcurrentHashMap<>();
+    if(containers != null) {
+      containers.forEach(c -> {
+        // Containers in ALLOCATED state should not be included while
+        // calculating the total number of containers here. They are not
+        // reported by DNs and hence should not affect the chill mode exit
+        // rule.
+        if (c != null && c.getState() != null &&
+            !c.getState().equals(HddsProtos.LifeCycleState.ALLOCATED)) {
+          containerMap.put(c.getContainerID(), c);
+        }
+      });
+      maxContainer = containerMap.size();
+    }
+  }
+
+  @Override
+  public boolean validate() {
+    if (maxContainer == 0) {
+      return true;
+    }
+    return getCurrentContainerThreshold() >= chillModeCutoff;
+  }
+
+  @VisibleForTesting
+  public double getCurrentContainerThreshold() {
+    if (maxContainer == 0) {
+      return 1;
+    }
+    return (containerWithMinReplicas.doubleValue() / maxContainer);
+  }
+
+  @Override
+  public void process(NodeRegistrationContainerReport reportsProto) {
+    if (maxContainer == 0) {
+      // No container to check.
+      return;
+    }
+
+    reportsProto.getReport().getReportsList().forEach(c -> {
+      if (containerMap.containsKey(c.getContainerID())) {
+        if(containerMap.remove(c.getContainerID()) != null) {
+          containerWithMinReplicas.getAndAdd(1);
+        }
+      }
+    });
+    if(chillModeManager.getInChillMode()) {
+      SCMChillModeManager.getLogger().info(
+          "SCM in chill mode. {} % containers have at least one"
+              + " reported replica.",
+          (containerWithMinReplicas.get() / maxContainer) * 100);
+    }
+  }
+
+  @Override
+  public void cleanup() {
+    containerMap.clear();
+  }
+}

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

@@ -0,0 +1,83 @@
+/**
+ * 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.chillmode;
+
+import java.util.HashSet;
+import java.util.UUID;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdds.HddsConfigKeys;
+import org.apache.hadoop.hdds.scm.server.SCMDatanodeProtocolServer.NodeRegistrationContainerReport;
+
+import com.google.common.annotations.VisibleForTesting;
+
+/**
+ * Class defining Chill mode exit criteria according to number of DataNodes
+ * registered with SCM.
+ */
+public class DataNodeChillModeRule implements
+    ChillModeExitRule<NodeRegistrationContainerReport> {
+
+  // Min DataNodes required to exit chill mode.
+  private int requiredDns;
+  private int registeredDns = 0;
+  // Set to track registered DataNodes.
+  private HashSet<UUID> registeredDnSet;
+
+  private final SCMChillModeManager chillModeManager;
+
+  public DataNodeChillModeRule(Configuration conf,
+      SCMChillModeManager manager) {
+    requiredDns = conf.getInt(
+        HddsConfigKeys.HDDS_SCM_CHILLMODE_MIN_DATANODE,
+        HddsConfigKeys.HDDS_SCM_CHILLMODE_MIN_DATANODE_DEFAULT);
+    registeredDnSet = new HashSet<>(requiredDns * 2);
+    chillModeManager = manager;
+  }
+
+  @Override
+  public boolean validate() {
+    return registeredDns >= requiredDns;
+  }
+
+  @VisibleForTesting
+  public double getRegisteredDataNodes() {
+    return registeredDns;
+  }
+
+  @Override
+  public void process(NodeRegistrationContainerReport reportsProto) {
+    if (requiredDns == 0) {
+      // No dn check required.
+      return;
+    }
+
+    if(chillModeManager.getInChillMode()) {
+      registeredDnSet.add(reportsProto.getDatanodeDetails().getUuid());
+      registeredDns = registeredDnSet.size();
+      SCMChillModeManager.getLogger().info(
+          "SCM in chill mode. {} DataNodes registered, {} required.",
+          registeredDns, requiredDns);
+    }
+  }
+
+  @Override
+  public void cleanup() {
+    registeredDnSet.clear();
+  }
+}

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

@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-package org.apache.hadoop.hdds.scm.server;
+package org.apache.hadoop.hdds.scm.chillmode;
 
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 

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

@@ -0,0 +1,153 @@
+/*
+ * 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.chillmode;
+
+import com.google.common.annotations.VisibleForTesting;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdds.HddsConfigKeys;
+import org.apache.hadoop.hdds.scm.container.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;
+
+/**
+ * StorageContainerManager enters chill mode on startup to allow system to
+ * reach a stable state before becoming fully functional. SCM will wait
+ * for certain resources to be reported before coming out of chill mode.
+ *
+ * ChillModeExitRule defines format to define new rules which must be satisfied
+ * to exit Chill mode.
+ * ContainerChillModeRule defines the only exit criteria right now.
+ * On every new datanode registration event this class adds replicas
+ * for reported containers and validates if cutoff threshold for
+ * containers is meet.
+ */
+public class SCMChillModeManager implements
+    EventHandler<NodeRegistrationContainerReport> {
+
+  private static final Logger LOG =
+      LoggerFactory.getLogger(SCMChillModeManager.class);
+  private final boolean isChillModeEnabled;
+  private AtomicBoolean inChillMode = new AtomicBoolean(true);
+  private Map<String, ChillModeExitRule> exitRules = new HashMap(1);
+  private Configuration config;
+  private static final String CONT_EXIT_RULE = "ContainerChillModeRule";
+  private static final String DN_EXIT_RULE = "DataNodeChillModeRule";
+  private final EventQueue eventPublisher;
+
+  public SCMChillModeManager(Configuration conf,
+      List<ContainerInfo> allContainers, EventQueue eventQueue) {
+    this.config = conf;
+    this.eventPublisher = eventQueue;
+    this.isChillModeEnabled = conf.getBoolean(
+        HddsConfigKeys.HDDS_SCM_CHILLMODE_ENABLED,
+        HddsConfigKeys.HDDS_SCM_CHILLMODE_ENABLED_DEFAULT);
+    if (isChillModeEnabled) {
+      exitRules.put(CONT_EXIT_RULE,
+          new ContainerChillModeRule(config, allContainers, this));
+      exitRules.put(DN_EXIT_RULE, new DataNodeChillModeRule(config, this));
+      emitChillModeStatus();
+    } else {
+      exitChillMode(eventQueue);
+    }
+  }
+
+  /**
+   * Emit Chill mode status.
+   */
+  @VisibleForTesting
+  public void emitChillModeStatus() {
+    eventPublisher.fireEvent(SCMEvents.CHILL_MODE_STATUS, getInChillMode());
+  }
+
+  private void validateChillModeExitRules(EventPublisher eventQueue) {
+    for (ChillModeExitRule exitRule : exitRules.values()) {
+      if (!exitRule.validate()) {
+        return;
+      }
+    }
+    exitChillMode(eventQueue);
+  }
+
+  /**
+   * Exit chill mode. It does following actions:
+   * 1. Set chill mode status to false.
+   * 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);
+
+    // TODO: Remove handler registration as there is no need to listen to
+    // register events anymore.
+
+    for (ChillModeExitRule e : exitRules.values()) {
+      e.cleanup();
+    }
+    emitChillModeStatus();
+  }
+
+  @Override
+  public void onMessage(
+      NodeRegistrationContainerReport nodeRegistrationContainerReport,
+      EventPublisher publisher) {
+    if (getInChillMode()) {
+      exitRules.get(CONT_EXIT_RULE).process(nodeRegistrationContainerReport);
+      exitRules.get(DN_EXIT_RULE).process(nodeRegistrationContainerReport);
+      validateChillModeExitRules(publisher);
+    }
+  }
+
+  public boolean getInChillMode() {
+    if (!isChillModeEnabled) {
+      return false;
+    }
+    return inChillMode.get();
+  }
+
+  /**
+   * Set chill mode status.
+   */
+  public void setInChillMode(boolean inChillMode) {
+    this.inChillMode.set(inChillMode);
+  }
+
+  public static Logger getLogger() {
+    return LOG;
+  }
+
+  @VisibleForTesting
+  public double getCurrentContainerThreshold() {
+    return ((ContainerChillModeRule) exitRules.get(CONT_EXIT_RULE))
+        .getCurrentContainerThreshold();
+  }
+
+}

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/chillmode/package-info.java

@@ -0,0 +1,18 @@
+/**
+ * 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.chillmode;

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

@@ -1,319 +0,0 @@
-/*
- * 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 com.google.common.annotations.VisibleForTesting;
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
-import java.util.concurrent.ConcurrentHashMap;
-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;
-import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ScmOps;
-import org.apache.hadoop.hdds.scm.container.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;
-
-/**
- * StorageContainerManager enters chill mode on startup to allow system to
- * reach a stable state before becoming fully functional. SCM will wait
- * for certain resources to be reported before coming out of chill mode.
- *
- * ChillModeExitRule defines format to define new rules which must be satisfied
- * to exit Chill mode.
- * ContainerChillModeRule defines the only exit criteria right now.
- * On every new datanode registration event this class adds replicas
- * for reported containers and validates if cutoff threshold for
- * containers is meet.
- */
-public class SCMChillModeManager implements
-    EventHandler<NodeRegistrationContainerReport> {
-
-  private static final Logger LOG =
-      LoggerFactory.getLogger(SCMChillModeManager.class);
-  private final boolean isChillModeEnabled;
-  private AtomicBoolean inChillMode = new AtomicBoolean(true);
-  private AtomicLong containerWithMinReplicas = new AtomicLong(0);
-  private Map<String, ChillModeExitRule> exitRules = new HashMap(1);
-  private Configuration config;
-  private static final String CONT_EXIT_RULE = "ContainerChillModeRule";
-  private static final String DN_EXIT_RULE = "DataNodeChillModeRule";
-  private final EventQueue eventPublisher;
-
-  SCMChillModeManager(Configuration conf, List<ContainerInfo> allContainers,
-      EventQueue eventQueue) {
-    this.config = conf;
-    this.eventPublisher = eventQueue;
-    this.isChillModeEnabled = conf.getBoolean(
-        HddsConfigKeys.HDDS_SCM_CHILLMODE_ENABLED,
-        HddsConfigKeys.HDDS_SCM_CHILLMODE_ENABLED_DEFAULT);
-    if (isChillModeEnabled) {
-      exitRules.put(CONT_EXIT_RULE,
-          new ContainerChillModeRule(config, allContainers));
-      exitRules.put(DN_EXIT_RULE, new DataNodeChillModeRule(config));
-      emitChillModeStatus();
-    } else {
-      exitChillMode(eventQueue);
-    }
-  }
-
-  /**
-   * Emit Chill mode status.
-   */
-  @VisibleForTesting
-  public void emitChillModeStatus() {
-    eventPublisher.fireEvent(SCMEvents.CHILL_MODE_STATUS, getInChillMode());
-  }
-
-  private void validateChillModeExitRules(EventPublisher eventQueue) {
-    for (ChillModeExitRule exitRule : exitRules.values()) {
-      if (!exitRule.validate()) {
-        return;
-      }
-    }
-    exitChillMode(eventQueue);
-  }
-
-  /**
-   * Exit chill mode. It does following actions:
-   * 1. Set chill mode status to false.
-   * 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);
-
-    // TODO: Remove handler registration as there is no need to listen to
-    // register events anymore.
-
-    for (ChillModeExitRule e : exitRules.values()) {
-      e.cleanup();
-    }
-    emitChillModeStatus();
-  }
-
-  @Override
-  public void onMessage(
-      NodeRegistrationContainerReport nodeRegistrationContainerReport,
-      EventPublisher publisher) {
-    if (getInChillMode()) {
-      exitRules.get(CONT_EXIT_RULE).process(nodeRegistrationContainerReport);
-      exitRules.get(DN_EXIT_RULE).process(nodeRegistrationContainerReport);
-      validateChillModeExitRules(publisher);
-    }
-  }
-
-  public boolean getInChillMode() {
-    if (!isChillModeEnabled) {
-      return false;
-    }
-    return inChillMode.get();
-  }
-
-  /**
-   * Set chill mode status.
-   */
-  public void setInChillMode(boolean inChillMode) {
-    this.inChillMode.set(inChillMode);
-  }
-
-  /**
-   * Interface for defining chill mode exit rules.
-   *
-   * @param <T>
-   */
-  public interface ChillModeExitRule<T> {
-
-    boolean validate();
-
-    void process(T report);
-
-    void cleanup();
-  }
-
-  /**
-   * Class defining Chill mode exit criteria for Containers.
-   */
-  public class ContainerChillModeRule implements
-      ChillModeExitRule<NodeRegistrationContainerReport> {
-
-    // Required cutoff % for containers with at least 1 reported replica.
-    private double chillModeCutoff;
-    // Containers read from scm db (excluding containers in ALLOCATED state).
-    private Map<Long, ContainerInfo> containerMap;
-    private double maxContainer;
-
-    public ContainerChillModeRule(Configuration conf,
-        List<ContainerInfo> containers) {
-      chillModeCutoff = conf
-          .getDouble(HddsConfigKeys.HDDS_SCM_CHILLMODE_THRESHOLD_PCT,
-              HddsConfigKeys.HDDS_SCM_CHILLMODE_THRESHOLD_PCT_DEFAULT);
-      containerMap = new ConcurrentHashMap<>();
-      if(containers != null) {
-        containers.forEach(c -> {
-          // Containers in ALLOCATED state should not be included while
-          // calculating the total number of containers here. They are not
-          // reported by DNs and hence should not affect the chill mode exit
-          // rule.
-          if (c != null && c.getState() != null &&
-              !c.getState().equals(HddsProtos.LifeCycleState.ALLOCATED)) {
-            containerMap.put(c.getContainerID(), c);
-          }
-        });
-        maxContainer = containerMap.size();
-      }
-    }
-
-    @Override
-    public boolean validate() {
-      if (maxContainer == 0) {
-        return true;
-      }
-      return getCurrentContainerThreshold() >= chillModeCutoff;
-    }
-
-    @VisibleForTesting
-    public double getCurrentContainerThreshold() {
-      if (maxContainer == 0) {
-        return 1;
-      }
-      return (containerWithMinReplicas.doubleValue() / maxContainer);
-    }
-
-    @Override
-    public void process(NodeRegistrationContainerReport reportsProto) {
-      if (maxContainer == 0) {
-        // No container to check.
-        return;
-      }
-
-      reportsProto.getReport().getReportsList().forEach(c -> {
-        if (containerMap.containsKey(c.getContainerID())) {
-          if(containerMap.remove(c.getContainerID()) != null) {
-            containerWithMinReplicas.getAndAdd(1);
-          }
-        }
-      });
-      if(getInChillMode()) {
-        LOG.info("SCM in chill mode. {} % containers have at least one"
-                + " reported replica.",
-            (containerWithMinReplicas.get() / maxContainer) * 100);
-      }
-    }
-
-    @Override
-    public void cleanup() {
-      containerMap.clear();
-    }
-  }
-
-  /**
-   * Class defining Chill mode exit criteria according to number of DataNodes
-   * registered with SCM.
-   */
-  public class DataNodeChillModeRule implements
-      ChillModeExitRule<NodeRegistrationContainerReport> {
-
-    // Min DataNodes required to exit chill mode.
-    private int requiredDns;
-    private int registeredDns = 0;
-    // Set to track registered DataNodes.
-    private HashSet<UUID> registeredDnSet;
-
-    public DataNodeChillModeRule(Configuration conf) {
-      requiredDns = conf
-          .getInt(HddsConfigKeys.HDDS_SCM_CHILLMODE_MIN_DATANODE,
-              HddsConfigKeys.HDDS_SCM_CHILLMODE_MIN_DATANODE_DEFAULT);
-      registeredDnSet = new HashSet<>(requiredDns * 2);
-    }
-
-    @Override
-    public boolean validate() {
-      return registeredDns >= requiredDns;
-    }
-
-    @VisibleForTesting
-    public double getRegisteredDataNodes() {
-      return registeredDns;
-    }
-
-    @Override
-    public void process(NodeRegistrationContainerReport reportsProto) {
-      if (requiredDns == 0) {
-        // No dn check required.
-        return;
-      }
-
-      if(getInChillMode()) {
-        registeredDnSet.add(reportsProto.getDatanodeDetails().getUuid());
-        registeredDns = registeredDnSet.size();
-        LOG.info("SCM in chill mode. {} DataNodes registered, {} required.",
-            registeredDns, requiredDns);
-      }
-    }
-
-    @Override
-    public void cleanup() {
-      registeredDnSet.clear();
-    }
-  }
-
-  @VisibleForTesting
-  public static Logger getLogger() {
-    return LOG;
-  }
-
-  @VisibleForTesting
-  public double getCurrentContainerThreshold() {
-    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);
-      restrictedOps.add(ScmOps.allocateContainer);
-    }
-
-    public static boolean isRestrictedInChillMode(ScmOps opName) {
-      return restrictedOps.contains(opName);
-    }
-  }
-
-}

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

@@ -33,6 +33,7 @@ import org.apache.hadoop.hdds.protocol.proto
 import org.apache.hadoop.hdds.scm.HddsServerUtil;
 import org.apache.hadoop.hdds.scm.ScmInfo;
 import org.apache.hadoop.hdds.scm.ScmUtils;
+import org.apache.hadoop.hdds.scm.chillmode.ChillModePrecheck;
 import org.apache.hadoop.hdds.scm.container.ContainerID;
 import org.apache.hadoop.hdds.scm.container.ContainerNotFoundException;
 import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline;

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

@@ -36,6 +36,7 @@ import org.apache.hadoop.hdds.scm.block.BlockManager;
 import org.apache.hadoop.hdds.scm.block.BlockManagerImpl;
 import org.apache.hadoop.hdds.scm.block.DeletedBlockLogImpl;
 import org.apache.hadoop.hdds.scm.block.PendingDeleteHandler;
+import org.apache.hadoop.hdds.scm.chillmode.SCMChillModeManager;
 import org.apache.hadoop.hdds.scm.command.CommandStatusReportHandler;
 import org.apache.hadoop.hdds.scm.container.CloseContainerEventHandler;
 import org.apache.hadoop.hdds.scm.container.CloseContainerWatcher;

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/chillmode/TestSCMChillModeManager.java

@@ -15,7 +15,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.hdds.scm.server;
+package org.apache.hadoop.hdds.scm.chillmode;
 
 import java.util.ArrayList;
 import java.util.List;

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/om/TestScmChillMode.java

@@ -30,11 +30,11 @@ import org.apache.hadoop.hdds.protocol.proto.HddsProtos.LifeCycleEvent;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationFactor;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.ReplicationType;
 import org.apache.hadoop.hdds.scm.container.SCMContainerManager;
+import org.apache.hadoop.hdds.scm.chillmode.SCMChillModeManager;
 import org.apache.hadoop.hdds.scm.container.ContainerInfo;
 import org.apache.hadoop.hdds.scm.events.SCMEvents;
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.scm.protocolPB.StorageContainerLocationProtocolClientSideTranslatorPB;
-import org.apache.hadoop.hdds.scm.server.SCMChillModeManager;
 import org.apache.hadoop.hdds.scm.server.SCMClientProtocolServer;
 import org.apache.hadoop.hdds.scm.server.StorageContainerManager;
 import org.apache.hadoop.ozone.HddsDatanodeService;