HBASE-18516 Removed dead code in ServerManager resulted mostly from AMv2 refactoring

* Call to methods sendRegionOpen(), isServerReachable(), removeRequeuedDeadServers(), getRequeuedDeadServers() got removed in HBASE-14614
* Call to method ServerManager.sendFavoredNodes() got removed in HBASE-17198

hbase-server/src/main/java/org/apache/hadoop/hbase/master/ServerManager.java

@@ -1,4 +1,4 @@
-/**
+/*
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -21,7 +21,6 @@ package org.apache.hadoop.hbase.master;
 import static org.apache.hadoop.hbase.util.CollectionUtils.computeIfAbsent;
 
 import java.io.IOException;
-import java.net.ConnectException;
 import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -53,31 +52,18 @@ import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.client.ClusterConnection;
 import org.apache.hadoop.hbase.client.RetriesExhaustedException;
-import org.apache.hadoop.hbase.ipc.FailedServerException;
 import org.apache.hadoop.hbase.ipc.HBaseRpcController;
 import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
 import org.apache.hadoop.hbase.master.balancer.BaseLoadBalancer;
 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
 import org.apache.hadoop.hbase.regionserver.HRegionServer;
-import org.apache.hadoop.hbase.regionserver.RegionOpeningState;
-import org.apache.hadoop.hbase.security.User;
-import org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException;
 import org.apache.hadoop.hbase.shaded.com.google.protobuf.UnsafeByteOperations;
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
-import org.apache.hadoop.hbase.shaded.protobuf.RequestConverter;
-import org.apache.hadoop.hbase.shaded.protobuf.ResponseConverter;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.AdminService;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.OpenRegionRequest;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.OpenRegionResponse;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.ServerInfo;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.UpdateFavoredNodesRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterStatusProtos.RegionStoreSequenceIds;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterStatusProtos.StoreSequenceId;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionServerStartupRequest;
 import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.Pair;
-import org.apache.hadoop.hbase.util.RetryCounter;
-import org.apache.hadoop.hbase.util.RetryCounterFactory;
 import org.apache.hadoop.hbase.zookeeper.ZKUtil;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
 import org.apache.zookeeper.KeeperException;
@@ -157,7 +143,6 @@ public class ServerManager {
   private final long maxSkew;
   private final long warningSkew;
 
-  private final RetryCounterFactory pingRetryCounterFactory;
   private final RpcControllerFactory rpcControllerFactory;
 
   /**
@@ -203,21 +188,16 @@ public class ServerManager {
    * @param master
    * @throws ZooKeeperConnectionException
    */
-  public ServerManager(final MasterServices master) throws IOException {
+  public ServerManager(final MasterServices master) {
     this(master, true);
   }
 
-  ServerManager(final MasterServices master, final boolean connect) throws IOException {
+  ServerManager(final MasterServices master, final boolean connect) {
     this.master = master;
     Configuration c = master.getConfiguration();
     maxSkew = c.getLong("hbase.master.maxclockskew", 30000);
     warningSkew = c.getLong("hbase.master.warningclockskew", 10000);
     this.connection = connect ? master.getClusterConnection() : null;
-    int pingMaxAttempts = Math.max(1, master.getConfiguration().getInt(
-      "hbase.master.maximum.ping.server.attempts", 10));
-    int pingSleepInterval = Math.max(1, master.getConfiguration().getInt(
-      "hbase.master.ping.server.retry.sleep.interval", 100));
-    this.pingRetryCounterFactory = new RetryCounterFactory(pingMaxAttempts, pingSleepInterval);
     this.rpcControllerFactory = this.connection == null
         ? null
         : connection.getRpcControllerFactory();
@@ -251,7 +231,7 @@ public class ServerManager {
     // Test for case where we get a region startup message from a regionserver
     // that has been quickly restarted but whose znode expiration handler has
     // not yet run, or from a server whose fail we are currently processing.
-    // Test its host+port combo is present in serverAddresstoServerInfo.  If it
+    // Test its host+port combo is present in serverAddressToServerInfo.  If it
     // is, reject the server and trigger its expiration. The next time it comes
     // in, it should have been removed from serverAddressToServerInfo and queued
     // for processing by ProcessServerShutdown.
@@ -443,7 +423,7 @@ public class ServerManager {
   /**
    * Adds the onlineServers list. onlineServers should be locked.
    * @param serverName The remote servers name.
-   * @param s
+   * @param sl
    */
   @VisibleForTesting
   void recordNewServerWithLock(final ServerName serverName, final ServerLoad sl) {
@@ -722,117 +702,6 @@ public class ServerManager {
 
   // RPC methods to region servers
 
-  /**
-   * Sends an OPEN RPC to the specified server to open the specified region.
-   * <p>
-   * Open should not fail but can if server just crashed.
-   * <p>
-   * @param server server to open a region
-   * @param region region to open
-   * @param favoredNodes
-   */
-  public RegionOpeningState sendRegionOpen(final ServerName server,
-      HRegionInfo region, List<ServerName> favoredNodes)
-  throws IOException {
-    AdminService.BlockingInterface admin = getRsAdmin(server);
-    if (admin == null) {
-      throw new IOException("Attempting to send OPEN RPC to server " + server.toString() +
-        " failed because no RPC connection found to this server");
-    }
-    OpenRegionRequest request =
-        RequestConverter.buildOpenRegionRequest(server, region, favoredNodes, false);
-    try {
-      OpenRegionResponse response = admin.openRegion(null, request);
-      return ResponseConverter.getRegionOpeningState(response);
-    } catch (ServiceException se) {
-      checkForRSznode(server, se);
-      throw ProtobufUtil.getRemoteException(se);
-    }
-  }
-
-  /**
-   * Check for an odd state, where we think an RS is up but it is not. Do it on OPEN.
-   * This is only case where the check makes sense.
-   *
-   * <p>We are checking for instance of HBASE-9593 where a RS registered but died before it put
-   * up its znode in zk. In this case, the RS made it into the list of online servers but it
-   * is not actually UP. We do the check here where there is an evident problem rather
-   * than do some crazy footwork where we'd have master check zk after a RS had reported
-   * for duty with provisional state followed by a confirmed state; that'd be a mess.
-   * Real fix is HBASE-17733.
-   */
-  private void checkForRSznode(final ServerName serverName, final ServiceException se) {
-    if (se.getCause() == null) return;
-    Throwable t = se.getCause();
-    if (t instanceof ConnectException) {
-      // If this, proceed to do cleanup.
-    } else {
-      // Look for FailedServerException
-      if (!(t instanceof IOException)) return;
-      if (t.getCause() == null) return;
-      if (!(t.getCause() instanceof FailedServerException)) return;
-      // Ok, found FailedServerException -- continue.
-    }
-    if (!isServerOnline(serverName)) return;
-    // We think this server is online. Check it has a znode up. Currently, a RS
-    // registers an ephereral znode in zk. If not present, something is up. Maybe
-    // HBASE-9593 where RS crashed AFTER reportForDuty but BEFORE it put up an ephemeral
-    // znode.
-    List<String> servers = null;
-    try {
-      servers = getRegionServersInZK(this.master.getZooKeeper());
-    } catch (KeeperException ke) {
-      LOG.warn("Failed to list regionservers", ke);
-      // ZK is malfunctioning, don't hang here
-    }
-    boolean found = false;
-    if (servers != null) {
-      for (String serverNameAsStr: servers) {
-        ServerName sn = ServerName.valueOf(serverNameAsStr);
-        if (sn.equals(serverName)) {
-          // Found a server up in zk.
-          found = true;
-          break;
-        }
-      }
-    }
-    if (!found) {
-      LOG.warn("Online server " + serverName.toString() + " has no corresponding " +
-        "ephemeral znode (Did it die before registering in zk?); " +
-          "calling expire to clean it up!");
-      expireServer(serverName);
-    }
-  }
-
-  /**
-   * Sends an OPEN RPC to the specified server to open the specified region.
-   * <p>
-   * Open should not fail but can if server just crashed.
-   * <p>
-   * @param server server to open a region
-   * @param regionOpenInfos info of a list of regions to open
-   * @return a list of region opening states
-   */
-  public List<RegionOpeningState> sendRegionOpen(ServerName server,
-      List<Pair<HRegionInfo, List<ServerName>>> regionOpenInfos)
-  throws IOException {
-    AdminService.BlockingInterface admin = getRsAdmin(server);
-    if (admin == null) {
-      throw new IOException("Attempting to send OPEN RPC to server " + server.toString() +
-        " failed because no RPC connection found to this server");
-    }
-
-    OpenRegionRequest request =
-        RequestConverter.buildOpenRegionRequest(server, regionOpenInfos, false);
-    try {
-      OpenRegionResponse response = admin.openRegion(null, request);
-      return ResponseConverter.getRegionOpeningStateList(response);
-    } catch (ServiceException se) {
-      checkForRSznode(server, se);
-      throw ProtobufUtil.getRemoteException(se);
-    }
-  }
-
   private HBaseRpcController newRpcController() {
     return rpcControllerFactory == null ? null : rpcControllerFactory.newController();
   }
@@ -892,41 +761,11 @@ public class ServerManager {
   }
 
   /**
-   * Check if a region server is reachable and has the expected start code
+   * @param sn
+   * @return Admin interface for the remote regionserver named <code>sn</code>
+   * @throws IOException
+   * @throws RetriesExhaustedException wrapping a ConnectException if failed
    */
-  public boolean isServerReachable(ServerName server) {
-    if (server == null) throw new NullPointerException("Passed server is null");
-
-
-    RetryCounter retryCounter = pingRetryCounterFactory.create();
-    while (retryCounter.shouldRetry()) {
-      try {
-        HBaseRpcController controller = newRpcController();
-        AdminService.BlockingInterface admin = getRsAdmin(server);
-        if (admin != null) {
-          ServerInfo info = ProtobufUtil.getServerInfo(controller, admin);
-          return info != null && info.hasServerName()
-            && server.getStartcode() == info.getServerName().getStartCode();
-        }
-      } catch (IOException ioe) {
-        LOG.debug("Couldn't reach " + server + ", try=" + retryCounter.getAttemptTimes()
-          + " of " + retryCounter.getMaxAttempts(), ioe);
-        try {
-          retryCounter.sleepUntilNextRetry();
-        } catch(InterruptedException ie) {
-          Thread.currentThread().interrupt();
-        }
-      }
-    }
-    return false;
-  }
-
-    /**
-    * @param sn
-    * @return Admin interface for the remote regionserver named <code>sn</code>
-    * @throws IOException
-    * @throws RetriesExhaustedException wrapping a ConnectException if failed
-    */
   public AdminService.BlockingInterface getRsAdmin(final ServerName sn)
   throws IOException {
     AdminService.BlockingInterface admin = this.rsAdmins.get(sn);
@@ -1088,23 +927,6 @@ public class ServerManager {
     return new HashSet<>(this.queuedDeadServers);
   }
 
-  /**
-   * During startup, if we figure it is not a failover, i.e. there is
-   * no more WAL files to split, we won't try to recover these dead servers.
-   * So we just remove them from the queue. Use caution in calling this.
-   */
-  void removeRequeuedDeadServers() {
-    requeuedDeadServers.clear();
-  }
-
-  /**
-   * @return A copy of the internal map of requeuedDeadServers servers and their corresponding
-   *         splitlog need flag.
-   */
-  Map<ServerName, Boolean> getRequeuedDeadServers() {
-    return Collections.unmodifiableMap(this.requeuedDeadServers);
-  }
-
   public boolean isServerOnline(ServerName serverName) {
     return serverName != null && onlineServers.containsKey(serverName);
   }
@@ -1157,11 +979,7 @@ public class ServerManager {
 
     // Loop through the draining server list and remove them from the server list
     final List<ServerName> drainingServersCopy = getDrainingServersList();
-    if (!drainingServersCopy.isEmpty()) {
+    destServers.removeAll(drainingServersCopy);
-      for (final ServerName server: drainingServersCopy) {
-        destServers.remove(server);
-      }
-    }
 
     // Remove the deadNotExpired servers from the server list.
     removeDeadNotExpiredServers(destServers);
@@ -1218,25 +1036,4 @@ public class ServerManager {
       removeRegion(hri);
     }
   }
-
-  public void sendFavoredNodes(final ServerName server,
-      Map<HRegionInfo, List<ServerName>> favoredNodes) throws IOException {
-    AdminService.BlockingInterface admin = getRsAdmin(server);
-    if (admin == null) {
-      LOG.warn("Attempting to send favored nodes update rpc to server " + server.toString()
-          + " failed because no RPC connection found to this server");
-    } else {
-      List<Pair<HRegionInfo, List<ServerName>>> regionUpdateInfos = new ArrayList<>();
-      for (Entry<HRegionInfo, List<ServerName>> entry : favoredNodes.entrySet()) {
-        regionUpdateInfos.add(new Pair<>(entry.getKey(), entry.getValue()));
-      }
-      UpdateFavoredNodesRequest request =
-        RequestConverter.buildUpdateFavoredNodesRequest(regionUpdateInfos);
-      try {
-        admin.updateFavoredNodes(null, request);
-      } catch (ServiceException se) {
-        throw ProtobufUtil.getRemoteException(se);
-      }
-    }
-  }
 }