HDDS-964. Fix test failure in TestOmMetrics. Contributed by Ajay Kumar.

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/MiniOzoneClusterImpl.java

@@ -246,7 +246,7 @@ public final class MiniOzoneClusterImpl implements MiniOzoneCluster {
   @Override
   public void restartOzoneManager() throws IOException {
     ozoneManager.stop();
-    ozoneManager.start();
+    ozoneManager.restart();
   }
 
   @Override

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OzoneManager.java

@@ -44,15 +44,14 @@ import org.apache.hadoop.hdds.security.x509.certificate.client.CertificateClient
 import org.apache.hadoop.hdds.server.ServiceRuntimeInfoImpl;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.io.Text;
-import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.ipc.Client;
 import org.apache.hadoop.ipc.ProtobufRpcEngine;
 import org.apache.hadoop.ipc.RPC;
+import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.ozone.OzoneSecurityUtil;
 import org.apache.hadoop.ozone.om.helpers.S3SecretValue;
 import org.apache.hadoop.ozone.security.OzoneSecurityException;
 import org.apache.hadoop.ozone.security.OzoneTokenIdentifier;
-import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
 import org.apache.hadoop.metrics2.util.MBeans;
 import org.apache.hadoop.net.NetUtils;
@@ -100,6 +99,7 @@ import org.apache.hadoop.ozone.security.acl.OzoneObjInfo;
 import org.apache.hadoop.ozone.security.acl.RequestContext;
 import org.apache.hadoop.ozone.security.OzoneBlockTokenSecretManager;
 import org.apache.hadoop.ozone.security.OzoneDelegationTokenSecretManager;
+import org.apache.hadoop.security.AccessControlException;
 import org.apache.hadoop.security.SecurityUtil;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.UserGroupInformation.AuthenticationMethod;
@@ -220,6 +220,7 @@ public final class OzoneManager extends ServiceRuntimeInfoImpl
   private JvmPauseMonitor jvmPauseMonitor;
   private final SecurityConfig secConfig;
   private final S3SecretManager s3SecretManager;
+  private volatile boolean isOmRpcServerRunning = false;
 
   private OzoneManager(OzoneConfiguration conf) throws IOException {
     Preconditions.checkNotNull(conf);
@@ -246,38 +247,12 @@ public final class OzoneManager extends ServiceRuntimeInfoImpl
       scmContainerClient = null;
       scmBlockClient = null;
     }
-    InetSocketAddress omNodeRpcAddr = getOmAddress(configuration);
-    int handlerCount = configuration.getInt(OZONE_OM_HANDLER_COUNT_KEY,
-        OZONE_OM_HANDLER_COUNT_DEFAULT);
-
-    // This is a temporary check. Once fully implemented, all OM state change
-    // should go through Ratis - either standalone (for non-HA) or replicated
-    // (for HA).
-    boolean omRatisEnabled = configuration.getBoolean(
-        OMConfigKeys.OZONE_OM_RATIS_ENABLE_KEY,
-        OMConfigKeys.OZONE_OM_RATIS_ENABLE_DEFAULT);
-    if (omRatisEnabled) {
-      omRatisServer = OzoneManagerRatisServer.newOMRatisServer(this, omId,
-          omNodeRpcAddr.getAddress(), configuration);
-      omRatisServer.start();
 
-      LOG.info("OzoneManager Ratis server started at port {}",
-          omRatisServer.getServerPort());
-
-      omRatisClient = OzoneManagerRatisClient.newOzoneManagerRatisClient(
-          omId, omRatisServer.getRaftGroup(), configuration);
-      omRatisClient.connect();
-    } else {
-      omRatisServer = null;
-      omRatisClient = null;
-    }
 
     RPC.setProtocolEngine(configuration, OzoneManagerProtocolPB.class,
         ProtobufRpcEngine.class);
 
-    BlockingService omService = newReflectiveBlockingService(
-        new OzoneManagerProtocolServerSideTranslatorPB(
-            this, omRatisClient, omRatisEnabled));
+
     omRpcAddressTxt = new Text(OmUtils.getOmRpcAddress(configuration));
     secConfig = new SecurityConfig(configuration);
     if (secConfig.isGrpcBlockTokenEnabled()) {
@@ -286,10 +261,8 @@ public final class OzoneManager extends ServiceRuntimeInfoImpl
     if(secConfig.isSecurityEnabled()){
       delegationTokenMgr = createDelegationTokenSecretManager(configuration);
     }
-
-    omRpcServer = startRpcServer(configuration, omNodeRpcAddr,
-        OzoneManagerProtocolPB.class, omService,
-        handlerCount);
+    InetSocketAddress omNodeRpcAddr = getOmAddress(configuration);
+    omRpcServer = getRpcServer(conf);
     omRpcAddress = updateRPCListenAddress(configuration,
         OZONE_OM_ADDRESS_KEY, omNodeRpcAddr, omRpcServer);
     metadataManager = new OmMetadataManagerImpl(configuration);
@@ -848,6 +821,53 @@ public final class OzoneManager extends ServiceRuntimeInfoImpl
 
     keyManager.start(configuration);
     omRpcServer.start();
+    isOmRpcServerRunning = true;
+    try {
+      httpServer = new OzoneManagerHttpServer(configuration, this);
+      httpServer.start();
+    } catch (Exception ex) {
+      // Allow OM to start as Http Server failure is not fatal.
+      LOG.error("OM HttpServer failed to start.", ex);
+    }
+    registerMXBean();
+    setStartTime();
+  }
+
+  /**
+   * Restarts the service. This method re-initializes the rpc server.
+   */
+  public void restart() throws IOException {
+    LOG.info(buildRpcServerStartMessage("OzoneManager RPC server",
+        omRpcAddress));
+
+
+    DefaultMetricsSystem.initialize("OzoneManager");
+
+    metadataManager.start(configuration);
+    startSecretManagerIfNecessary();
+
+    // Set metrics and start metrics back ground thread
+    metrics.setNumVolumes(metadataManager.countRowsInTable(metadataManager
+        .getVolumeTable()));
+    metrics.setNumBuckets(metadataManager.countRowsInTable(metadataManager
+        .getBucketTable()));
+
+    if (getMetricsStorageFile().exists()) {
+      OmMetricsInfo metricsInfo = READER.readValue(getMetricsStorageFile());
+      metrics.setNumKeys(metricsInfo.getNumKeys());
+    }
+
+    // Schedule save metrics
+    long period = configuration.getTimeDuration(OZONE_OM_METRICS_SAVE_INTERVAL,
+        OZONE_OM_METRICS_SAVE_INTERVAL_DEFAULT, TimeUnit.MILLISECONDS);
+    scheduleOMMetricsWriteTask = new ScheduleOMMetricsWriteTask();
+    metricsTimer = new Timer();
+    metricsTimer.schedule(scheduleOMMetricsWriteTask, 0, period);
+
+    keyManager.start(configuration);
+    omRpcServer = getRpcServer(configuration);
+    omRpcServer.start();
+    isOmRpcServerRunning = true;
     try {
       httpServer = new OzoneManagerHttpServer(configuration, this);
       httpServer.start();
@@ -864,6 +884,51 @@ public final class OzoneManager extends ServiceRuntimeInfoImpl
     setStartTime();
   }
 
+  /**
+   * Creates a new instance of rpc server. If an earlier instance is already
+   * running then returns the same.
+   */
+  private RPC.Server getRpcServer(OzoneConfiguration conf) throws IOException {
+    if (isOmRpcServerRunning) {
+      return omRpcServer;
+    }
+
+    InetSocketAddress omNodeRpcAddr = getOmAddress(configuration);
+    // This is a temporary check. Once fully implemented, all OM state change
+    // should go through Ratis - either standalone (for non-HA) or replicated
+    // (for HA).
+    boolean omRatisEnabled = configuration.getBoolean(
+        OMConfigKeys.OZONE_OM_RATIS_ENABLE_KEY,
+        OMConfigKeys.OZONE_OM_RATIS_ENABLE_DEFAULT);
+    if (omRatisEnabled) {
+      omRatisServer = OzoneManagerRatisServer.newOMRatisServer(this, omId,
+          omNodeRpcAddr.getAddress(), configuration);
+      omRatisServer.start();
+
+      LOG.info("OzoneManager Ratis server started at port {}",
+          omRatisServer.getServerPort());
+
+      omRatisClient = OzoneManagerRatisClient.newOzoneManagerRatisClient(
+          omId, omRatisServer.getRaftGroup(), configuration);
+      omRatisClient.connect();
+    } else {
+      omRatisServer = null;
+      omRatisClient = null;
+    }
+
+    final int handlerCount = conf.getInt(OZONE_OM_HANDLER_COUNT_KEY,
+        OZONE_OM_HANDLER_COUNT_DEFAULT);
+    RPC.setProtocolEngine(configuration, OzoneManagerProtocolPB.class,
+        ProtobufRpcEngine.class);
+
+    BlockingService omService = newReflectiveBlockingService(
+        new OzoneManagerProtocolServerSideTranslatorPB(this, omRatisClient,
+            omRatisEnabled));
+    return startRpcServer(configuration, omNodeRpcAddr,
+        OzoneManagerProtocolPB.class, omService,
+        handlerCount);
+  }
+
   /**
    * Stop service.
    */
@@ -879,6 +944,7 @@ public final class OzoneManager extends ServiceRuntimeInfoImpl
       if (omRatisServer != null) {
         omRatisServer.stop();
       }
+      isOmRpcServerRunning = false;
       keyManager.stop();
       stopSecretManager();
       httpServer.stop();