HDDS-217. Move all SCMEvents to a package.

Contributed by Anu Engineer.

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

@@ -24,15 +24,14 @@ import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline
 import org.apache.hadoop.hdds.scm.exceptions.SCMException;
 import org.apache.hadoop.hdds.server.events.EventHandler;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
-import org.apache.hadoop.hdds.server.events.TypedEvent;
 import org.apache.hadoop.ozone.protocol.commands.CloseContainerCommand;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * In case of a node failure, volume failure, volume out of spapce, node
- * out of space etc, CLOSE_CONTAINER_EVENT will be triggered.
- * CloseContainerEventHandler is the handler for CLOSE_CONTAINER_EVENT.
+ * out of space etc, CLOSE_CONTAINER will be triggered.
+ * CloseContainerEventHandler is the handler for CLOSE_CONTAINER.
  * When a close container event is fired, a close command for the container
  * should be sent to all the datanodes in the pipeline and containerStateManager
  * needs to update the container state to Closing.
@@ -42,8 +41,6 @@ public class CloseContainerEventHandler implements EventHandler<ContainerID> {
   public static final Logger LOG =
       LoggerFactory.getLogger(CloseContainerEventHandler.class);
 
-  public static final TypedEvent<ContainerID> CLOSE_CONTAINER_EVENT =
-            new TypedEvent<>(ContainerID.class);
 
   private final Mapping containerManager;
 
@@ -59,7 +56,8 @@ public class CloseContainerEventHandler implements EventHandler<ContainerID> {
     ContainerWithPipeline containerWithPipeline = null;
     ContainerInfo info;
     try {
-      containerWithPipeline = containerManager.getContainerWithPipeline(containerID.getId());
+      containerWithPipeline =
+          containerManager.getContainerWithPipeline(containerID.getId());
       info = containerWithPipeline.getContainerInfo();
       if (info == null) {
         LOG.info("Failed to update the container state. Container with id : {} "
@@ -73,7 +71,8 @@ public class CloseContainerEventHandler implements EventHandler<ContainerID> {
     }
 
     if (info.getState() == HddsProtos.LifeCycleState.OPEN) {
-      for (DatanodeDetails datanode : containerWithPipeline.getPipeline().getMachines()) {
+      for (DatanodeDetails datanode :
+          containerWithPipeline.getPipeline().getMachines()) {
         containerManager.getNodeManager().addDatanodeCommand(datanode.getUuid(),
             new CloseContainerCommand(containerID.getId(),
                 info.getReplicationType()));

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

@@ -0,0 +1,80 @@
+/*
+ * 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.events;
+
+import org.apache.hadoop.hdds.scm.container.ContainerID;
+import org.apache.hadoop.hdds.scm.server.SCMDatanodeHeartbeatDispatcher.ContainerReportFromDatanode;
+import org.apache.hadoop.hdds.scm.server.SCMDatanodeHeartbeatDispatcher.NodeReportFromDatanode;
+
+import org.apache.hadoop.hdds.server.events.Event;
+import org.apache.hadoop.hdds.server.events.TypedEvent;
+import org.apache.hadoop.ozone.protocol.commands.CommandForDatanode;
+
+/**
+ * Class that acts as the namespace for all SCM Events.
+ */
+public final class SCMEvents {
+
+  /**
+   * NodeReports are  sent out by Datanodes. This report is
+   * received by SCMDatanodeHeartbeatDispatcher and NodeReport Event is
+   * generated.
+   */
+  public static final TypedEvent<NodeReportFromDatanode> NODE_REPORT =
+      new TypedEvent<>(NodeReportFromDatanode.class, "Node_Report");
+  /**
+   * ContainerReports are send out by Datanodes. This report
+   * is received by SCMDatanodeHeartbeatDispatcher and Container_Report Event
+   * i generated.
+   */
+  public static final TypedEvent<ContainerReportFromDatanode> CONTAINER_REPORT =
+      new TypedEvent<>(ContainerReportFromDatanode.class, "Container_Report");
+
+  /**
+   * When ever a command for the Datanode needs to be issued by any component
+   * inside SCM, a Datanode_Command event is generated. NodeManager listens
+   * to these events and dispatches them to Datanode for further processing.
+   */
+  public static final Event<CommandForDatanode> DATANODE_COMMAND =
+      new TypedEvent<>(CommandForDatanode.class, "Datanode_Command");
+
+  /**
+   * A Close Container Event can be triggered under many condition.
+   * Some of them are:
+   *    1. A Container is full, then we stop writing further information to
+   *    that container. DN's let SCM know that current state and sends a
+   *    informational message that allows SCM to close the container.
+   *
+   *    2. If a pipeline is open; for example Ratis; if a single node fails,
+   *    we will proactively close these containers.
+   *
+   *  Once a command is dispatched to DN, we will also listen to updates from
+   *  the datanode which lets us know that this command completed or timed out.
+   */
+  public static final TypedEvent<ContainerID> CLOSE_CONTAINER =
+      new TypedEvent<>(ContainerID.class, "Close_Container");
+
+  /**
+   * Private Ctor. Never Constructed.
+   */
+  private SCMEvents() {
+  }
+
+}

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

@@ -0,0 +1,23 @@
+/*
+ * 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.
+ *
+ */
+/**
+ * Events Package contains all the Events used by SCM internally to
+ * communicate between different sub-systems that make up SCM.
+ */
+package org.apache.hadoop.hdds.scm.events;

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

@@ -25,10 +25,8 @@ import org.apache.hadoop.hdds.scm.server.StorageContainerManager;
 import org.apache.hadoop.hdds.scm.VersionInfo;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeMetric;
 import org.apache.hadoop.hdds.scm.container.placement.metrics.SCMNodeStat;
-import org.apache.hadoop.hdds.server.events.Event;
 import org.apache.hadoop.hdds.server.events.EventHandler;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
-import org.apache.hadoop.hdds.server.events.TypedEvent;
 import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos.NodeState;
@@ -118,8 +116,7 @@ public class SCMNodeManager
   // Node pool manager.
   private final StorageContainerManager scmManager;
 
-  public static final Event<CommandForDatanode> DATANODE_COMMAND =
-      new TypedEvent<>(CommandForDatanode.class, "DATANODE_COMMAND");
+
 
   /**
    * Constructs SCM machine Manager.

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

@@ -25,12 +25,14 @@ import org.apache.hadoop.hdds.protocol.proto
 import org.apache.hadoop.hdds.protocol.proto
     .StorageContainerDatanodeProtocolProtos.SCMHeartbeatRequestProto;
 import org.apache.hadoop.hdds.server.events.EventPublisher;
-import org.apache.hadoop.hdds.server.events.TypedEvent;
 
 import com.google.protobuf.GeneratedMessage;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.CONTAINER_REPORT;
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.NODE_REPORT;
+
 /**
  * This class is responsible for dispatching heartbeat from datanode to
  * appropriate EventHandler at SCM.
@@ -42,11 +44,6 @@ public final class SCMDatanodeHeartbeatDispatcher {
 
   private EventPublisher eventPublisher;
 
-  public static final TypedEvent<NodeReportFromDatanode> NODE_REPORT =
-      new TypedEvent<>(NodeReportFromDatanode.class);
-
-  public static final TypedEvent<ContainerReportFromDatanode> CONTAINER_REPORT =
-      new TypedEvent<ContainerReportFromDatanode>(ContainerReportFromDatanode.class);
 
   public SCMDatanodeHeartbeatDispatcher(EventPublisher eventPublisher) {
     this.eventPublisher = eventPublisher;
@@ -63,12 +60,14 @@ public final class SCMDatanodeHeartbeatDispatcher {
         DatanodeDetails.getFromProtoBuf(heartbeat.getDatanodeDetails());
     // should we dispatch heartbeat through eventPublisher?
     if (heartbeat.hasNodeReport()) {
+      LOG.debug("Dispatching Node Report.");
       eventPublisher.fireEvent(NODE_REPORT,
           new NodeReportFromDatanode(datanodeDetails,
               heartbeat.getNodeReport()));
     }
 
     if (heartbeat.hasContainerReport()) {
+      LOG.debug("Dispatching Container Report.");
       eventPublisher.fireEvent(CONTAINER_REPORT,
           new ContainerReportFromDatanode(datanodeDetails,
               heartbeat.getContainerReport()));

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

@@ -70,6 +70,8 @@ import java.util.concurrent.TimeUnit;
 
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_DB_CACHE_SIZE_DEFAULT;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_DB_CACHE_SIZE_MB;
+
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.DATANODE_COMMAND;
 import static org.apache.hadoop.ozone.OzoneConfigKeys.OZONE_ENABLED;
 import static org.apache.hadoop.util.ExitUtil.terminate;
 
@@ -164,9 +166,10 @@ public final class StorageContainerManager extends ServiceRuntimeInfoImpl
     }
     EventQueue eventQueue = new EventQueue();
 
-    SCMNodeManager nm = new SCMNodeManager(conf, scmStorage.getClusterID(), this);
+    SCMNodeManager nm =
+        new SCMNodeManager(conf, scmStorage.getClusterID(), this);
     scmNodeManager = nm;
-    eventQueue.addHandler(SCMNodeManager.DATANODE_COMMAND, nm);
+    eventQueue.addHandler(DATANODE_COMMAND, nm);
 
     scmContainerManager = new ContainerMapping(conf, getScmNodeManager(),
         cacheSize);

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

@@ -17,11 +17,13 @@
 
 package org.apache.hadoop.hdds.scm.container;
 
+import org.apache.commons.lang3.RandomUtils;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileUtil;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.proto.HddsProtos;
-import org.apache.hadoop.hdds.scm.container.common.helpers.ContainerWithPipeline;
+import org.apache.hadoop.hdds.scm.container.common.helpers
+    .ContainerWithPipeline;
 import org.apache.hadoop.hdds.server.events.EventQueue;
 import org.apache.hadoop.ozone.OzoneConfigKeys;
 import org.apache.hadoop.ozone.container.common.SCMTestUtils;
@@ -33,12 +35,12 @@ import org.junit.Test;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.Random;
 
 import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.LifeCycleEvent.CREATE;
 import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.LifeCycleEvent.CREATED;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_CONTAINER_SIZE_DEFAULT;
 import static org.apache.hadoop.hdds.scm.ScmConfigKeys.OZONE_SCM_CONTAINER_SIZE_GB;
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.CLOSE_CONTAINER;
 
 /**
  * Tests the closeContainerEventHandler class.
@@ -65,7 +67,7 @@ public class TestCloseContainerEventHandler {
     nodeManager = new MockNodeManager(true, 10);
     mapping = new ContainerMapping(configuration, nodeManager, 128);
     eventQueue = new EventQueue();
-    eventQueue.addHandler(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT,
+    eventQueue.addHandler(CLOSE_CONTAINER,
         new CloseContainerEventHandler(mapping));
   }
 
@@ -81,8 +83,8 @@ public class TestCloseContainerEventHandler {
   public void testIfCloseContainerEventHadnlerInvoked() {
     GenericTestUtils.LogCapturer logCapturer = GenericTestUtils.LogCapturer
         .captureLogs(CloseContainerEventHandler.LOG);
-    eventQueue.fireEvent(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT,
-        new ContainerID(Math.abs(new Random().nextLong())));
+    eventQueue.fireEvent(CLOSE_CONTAINER,
+        new ContainerID(Math.abs(RandomUtils.nextInt())));
     eventQueue.processAll(1000);
     Assert.assertTrue(logCapturer.getOutput()
         .contains("Close container Event triggered for container"));
@@ -90,10 +92,10 @@ public class TestCloseContainerEventHandler {
 
   @Test
   public void testCloseContainerEventWithInvalidContainer() {
-    long id = Math.abs(new Random().nextLong());
+    long id = Math.abs(RandomUtils.nextInt());
     GenericTestUtils.LogCapturer logCapturer = GenericTestUtils.LogCapturer
         .captureLogs(CloseContainerEventHandler.LOG);
-    eventQueue.fireEvent(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT,
+    eventQueue.fireEvent(CLOSE_CONTAINER,
         new ContainerID(id));
     eventQueue.processAll(1000);
     Assert.assertTrue(logCapturer.getOutput()
@@ -112,7 +114,7 @@ public class TestCloseContainerEventHandler {
         containerWithPipeline.getContainerInfo().getContainerID());
     DatanodeDetails datanode = containerWithPipeline.getPipeline().getLeader();
     int closeCount = nodeManager.getCommandCount(datanode);
-    eventQueue.fireEvent(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT, id);
+    eventQueue.fireEvent(CLOSE_CONTAINER, id);
     eventQueue.processAll(1000);
     // At this point of time, the allocated container is not in open
     // state, so firing close container event should not queue CLOSE
@@ -125,11 +127,12 @@ public class TestCloseContainerEventHandler {
     //Execute these state transitions so that we can close the container.
     mapping.updateContainerState(id.getId(), CREATE);
     mapping.updateContainerState(id.getId(), CREATED);
-    eventQueue.fireEvent(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT,
+    eventQueue.fireEvent(CLOSE_CONTAINER,
         new ContainerID(
             containerWithPipeline.getContainerInfo().getContainerID()));
     eventQueue.processAll(1000);
-    Assert.assertEquals(closeCount + 1, nodeManager.getCommandCount(datanode));
+    Assert.assertEquals(closeCount + 1,
+        nodeManager.getCommandCount(datanode));
     Assert.assertEquals(HddsProtos.LifeCycleState.CLOSING,
         mapping.getStateManager().getContainer(id).getState());
   }
@@ -145,7 +148,7 @@ public class TestCloseContainerEventHandler {
     ContainerID id = new ContainerID(
         containerWithPipeline.getContainerInfo().getContainerID());
     int[] closeCount = new int[3];
-    eventQueue.fireEvent(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT, id);
+    eventQueue.fireEvent(CLOSE_CONTAINER, id);
     eventQueue.processAll(1000);
     int i = 0;
     for (DatanodeDetails details : containerWithPipeline.getPipeline()
@@ -166,7 +169,7 @@ public class TestCloseContainerEventHandler {
     //Execute these state transitions so that we can close the container.
     mapping.updateContainerState(id.getId(), CREATE);
     mapping.updateContainerState(id.getId(), CREATED);
-    eventQueue.fireEvent(CloseContainerEventHandler.CLOSE_CONTAINER_EVENT, id);
+    eventQueue.fireEvent(CLOSE_CONTAINER, id);
     eventQueue.processAll(1000);
     i = 0;
     // Make sure close is queued for each datanode on the pipeline

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/node/TestNodeManager.java

@@ -68,6 +68,7 @@ import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.NodeState.DEAD;
 import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.NodeState
     .HEALTHY;
 import static org.apache.hadoop.hdds.protocol.proto.HddsProtos.NodeState.STALE;
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.DATANODE_COMMAND;
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.core.StringStartsWith.startsWith;
 import static org.junit.Assert.assertEquals;
@@ -1068,11 +1069,6 @@ public class TestNodeManager {
       foundRemaining = nodeManager.getStats().getRemaining().get();
       assertEquals(0, foundRemaining);
 
-      // Send a new report to bring the dead node back to healthy
-      String storagePath = testDir.getAbsolutePath() + "/" + dnId;
-      List<StorageReportProto> reports = TestUtils
-          .createStorageReport(capacity, expectedScmUsed, expectedRemaining,
-              storagePath, null, dnId, 1);
       nodeManager.processHeartbeat(datanodeDetails);
 
       // Wait up to 5 seconds so that the dead node becomes healthy
@@ -1111,11 +1107,11 @@ public class TestNodeManager {
 
     EventQueue eq = new EventQueue();
     try (SCMNodeManager nodemanager = createNodeManager(conf)) {
-      eq.addHandler(SCMNodeManager.DATANODE_COMMAND, nodemanager);
+      eq.addHandler(DATANODE_COMMAND, nodemanager);
 
       nodemanager
           .register(datanodeDetails, TestUtils.createNodeReport(reports));
-      eq.fireEvent(SCMNodeManager.DATANODE_COMMAND,
+      eq.fireEvent(DATANODE_COMMAND,
           new CommandForDatanode(datanodeDetails.getUuid(),
               new CloseContainerCommand(1L, ReplicationType.STAND_ALONE)));
 

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

@@ -20,8 +20,6 @@ package org.apache.hadoop.hdds.scm.server;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hdds.conf.OzoneConfiguration;
 import org.apache.hadoop.hdds.protocol.DatanodeDetails;
 import org.apache.hadoop.hdds.protocol.proto
     .StorageContainerDatanodeProtocolProtos.ContainerReportsProto;
@@ -40,6 +38,9 @@ import org.apache.hadoop.hdds.server.events.EventPublisher;
 import org.junit.Assert;
 import org.junit.Test;
 
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.CONTAINER_REPORT;
+import static org.apache.hadoop.hdds.scm.events.SCMEvents.NODE_REPORT;
+
 /**
  * This class tests the behavior of SCMDatanodeHeartbeatDispatcher.
  */
@@ -49,8 +50,6 @@ public class TestSCMDatanodeHeartbeatDispatcher {
   @Test
   public void testNodeReportDispatcher() throws IOException {
 
-    Configuration conf = new OzoneConfiguration();
-
     AtomicInteger eventReceived = new AtomicInteger();
 
     NodeReportProto nodeReport = NodeReportProto.getDefaultInstance();
@@ -60,10 +59,10 @@ public class TestSCMDatanodeHeartbeatDispatcher {
           @Override
           public <PAYLOAD, EVENT_TYPE extends Event<PAYLOAD>> void fireEvent(
               EVENT_TYPE event, PAYLOAD payload) {
-            Assert.assertEquals(event,
-                SCMDatanodeHeartbeatDispatcher.NODE_REPORT);
+            Assert.assertEquals(event, NODE_REPORT);
             eventReceived.incrementAndGet();
-            Assert.assertEquals(nodeReport, ((NodeReportFromDatanode)payload).getReport());
+            Assert.assertEquals(nodeReport,
+                ((NodeReportFromDatanode)payload).getReport());
 
           }
         });
@@ -84,7 +83,6 @@ public class TestSCMDatanodeHeartbeatDispatcher {
   @Test
   public void testContainerReportDispatcher() throws IOException {
 
-    Configuration conf = new OzoneConfiguration();
 
     AtomicInteger eventReceived = new AtomicInteger();
 
@@ -96,9 +94,9 @@ public class TestSCMDatanodeHeartbeatDispatcher {
           @Override
           public <PAYLOAD, EVENT_TYPE extends Event<PAYLOAD>> void fireEvent(
               EVENT_TYPE event, PAYLOAD payload) {
-            Assert.assertEquals(event,
-                SCMDatanodeHeartbeatDispatcher.CONTAINER_REPORT);
-            Assert.assertEquals(containerReport, ((ContainerReportFromDatanode)payload).getReport());
+            Assert.assertEquals(event, CONTAINER_REPORT);
+            Assert.assertEquals(containerReport,
+                ((ContainerReportFromDatanode)payload).getReport());
             eventReceived.incrementAndGet();
           }
         });