HBASE-25292 [branch-2.4] Improve InetSocketAddress usage discipline

hbase-client/src/main/java/org/apache/hadoop/hbase/client/AsyncConnectionImpl.java

@@ -77,8 +77,6 @@ class AsyncConnectionImpl implements AsyncConnection {
       .setUncaughtExceptionHandler(Threads.LOGGING_EXCEPTION_HANDLER).build(),
     10, TimeUnit.MILLISECONDS);
 
-  private static final String RESOLVE_HOSTNAME_ON_FAIL_KEY = "hbase.resolve.hostnames.on.failure";
-
   private final Configuration conf;
 
   final AsyncConnectionConfiguration connConf;
@@ -93,8 +91,6 @@ class AsyncConnectionImpl implements AsyncConnection {
 
   final RpcControllerFactory rpcControllerFactory;
 
-  private final boolean hostnameCanChange;
-
   private final AsyncRegionLocator locator;
 
   final AsyncRpcRetryingCallerFactory callerFactory;
@@ -137,7 +133,6 @@ public AsyncConnectionImpl(Configuration conf, ConnectionRegistry registry, Stri
     }
     this.rpcClient = RpcClientFactory.createClient(conf, clusterId, metrics.orElse(null));
     this.rpcControllerFactory = RpcControllerFactory.instantiate(conf);
-    this.hostnameCanChange = conf.getBoolean(RESOLVE_HOSTNAME_ON_FAIL_KEY, true);
     this.rpcTimeout =
       (int) Math.min(Integer.MAX_VALUE, TimeUnit.NANOSECONDS.toMillis(connConf.getRpcTimeoutNs()));
     this.locator = new AsyncRegionLocator(this, RETRY_TIMER);
@@ -258,7 +253,7 @@ private ClientService.Interface createRegionServerStub(ServerName serverName) th
 
   ClientService.Interface getRegionServerStub(ServerName serverName) throws IOException {
     return ConcurrentMapUtils.computeIfAbsentEx(rsStubs,
-      getStubKey(ClientService.getDescriptor().getName(), serverName, hostnameCanChange),
+      getStubKey(ClientService.getDescriptor().getName(), serverName),
       () -> createRegionServerStub(serverName));
   }
 
@@ -272,7 +267,7 @@ private AdminService.Interface createAdminServerStub(ServerName serverName) thro
 
   AdminService.Interface getAdminStub(ServerName serverName) throws IOException {
     return ConcurrentMapUtils.computeIfAbsentEx(adminSubs,
-      getStubKey(AdminService.getDescriptor().getName(), serverName, hostnameCanChange),
+      getStubKey(AdminService.getDescriptor().getName(), serverName),
       () -> createAdminServerStub(serverName));
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java

@@ -165,9 +165,6 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
     "hbase.client.master.state.cache.timeout.sec";
   private static final Logger LOG = LoggerFactory.getLogger(ConnectionImplementation.class);
 
-  private static final String RESOLVE_HOSTNAME_ON_FAIL_KEY = "hbase.resolve.hostnames.on.failure";
-
-  private final boolean hostnamesCanChange;
   private final long pause;
   private final long pauseForCQTBE;// pause for CallQueueTooBigException, if specified
   // The mode tells if HedgedRead, LoadBalance mode is supported.
@@ -308,7 +305,6 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
 
     boolean shouldListen =
       conf.getBoolean(HConstants.STATUS_PUBLISHED, HConstants.STATUS_PUBLISHED_DEFAULT);
-    this.hostnamesCanChange = conf.getBoolean(RESOLVE_HOSTNAME_ON_FAIL_KEY, true);
     Class<? extends ClusterStatusListener.Listener> listenerClass =
       conf.getClass(ClusterStatusListener.STATUS_LISTENER_CLASS,
         ClusterStatusListener.DEFAULT_STATUS_LISTENER_CLASS, ClusterStatusListener.Listener.class);
@@ -511,8 +507,8 @@ public Hbck getHbck(ServerName masterServer) throws IOException {
     if (isDeadServer(masterServer)) {
       throw new RegionServerStoppedException(masterServer + " is dead.");
     }
-    String key = getStubKey(MasterProtos.HbckService.BlockingInterface.class.getName(),
-      masterServer, this.hostnamesCanChange);
+    String key =
+      getStubKey(MasterProtos.HbckService.BlockingInterface.class.getName(), masterServer);
 
     return new HBaseHbck(
       (MasterProtos.HbckService.BlockingInterface) computeIfAbsentEx(stubs, key, () -> {
@@ -1306,8 +1302,7 @@ private MasterProtos.MasterService.BlockingInterface makeStubNoRetries()
         throw new MasterNotRunningException(sn + " is dead.");
       }
       // Use the security info interface name as our stub key
-      String key =
-        getStubKey(MasterProtos.MasterService.getDescriptor().getName(), sn, hostnamesCanChange);
+      String key = getStubKey(MasterProtos.MasterService.getDescriptor().getName(), sn);
       MasterProtos.MasterService.BlockingInterface stub =
         (MasterProtos.MasterService.BlockingInterface) computeIfAbsentEx(stubs, key, () -> {
           BlockingRpcChannel channel = rpcClient.createBlockingRpcChannel(sn, user, rpcTimeout);
@@ -1355,8 +1350,7 @@ public AdminProtos.AdminService.BlockingInterface getAdmin(ServerName serverName
     if (isDeadServer(serverName)) {
       throw new RegionServerStoppedException(serverName + " is dead.");
     }
-    String key = getStubKey(AdminProtos.AdminService.BlockingInterface.class.getName(), serverName,
-      this.hostnamesCanChange);
+    String key = getStubKey(AdminProtos.AdminService.BlockingInterface.class.getName(), serverName);
     return (AdminProtos.AdminService.BlockingInterface) computeIfAbsentEx(stubs, key, () -> {
       BlockingRpcChannel channel =
         this.rpcClient.createBlockingRpcChannel(serverName, user, rpcTimeout);
@@ -1370,8 +1364,8 @@ public BlockingInterface getClient(ServerName serverName) throws IOException {
     if (isDeadServer(serverName)) {
       throw new RegionServerStoppedException(serverName + " is dead.");
     }
-    String key = getStubKey(ClientProtos.ClientService.BlockingInterface.class.getName(),
-      serverName, this.hostnamesCanChange);
+    String key =
+      getStubKey(ClientProtos.ClientService.BlockingInterface.class.getName(), serverName);
     return (ClientProtos.ClientService.BlockingInterface) computeIfAbsentEx(stubs, key, () -> {
       BlockingRpcChannel channel =
         this.rpcClient.createBlockingRpcChannel(serverName, user, rpcTimeout);

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java

@@ -24,7 +24,6 @@
 
 import java.io.IOException;
 import java.lang.reflect.UndeclaredThrowableException;
-import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.Arrays;
 import java.util.List;
@@ -152,32 +151,17 @@ public boolean isTableDisabled(TableName tableName) throws IOException {
   }
 
   /**
-   * Return retires + 1. The returned value will be in range [1, Integer.MAX_VALUE].
+   * Get a unique key for the rpc stub to the given server.
    */
-  static int retries2Attempts(int retries) {
-    return Math.max(1, retries == Integer.MAX_VALUE ? Integer.MAX_VALUE : retries + 1);
+  static String getStubKey(String serviceName, ServerName serverName) {
+    return String.format("%s@%s", serviceName, serverName);
   }
 
   /**
-   * Get a unique key for the rpc stub to the given server.
+   * Return retires + 1. The returned value will be in range [1, Integer.MAX_VALUE].
    */
-  static String getStubKey(String serviceName, ServerName serverName, boolean hostnameCanChange) {
-    // Sometimes, servers go down and they come back up with the same hostname but a different
-    // IP address. Force a resolution of the rsHostname by trying to instantiate an
-    // InetSocketAddress, and this way we will rightfully get a new stubKey.
-    // Also, include the hostname in the key so as to take care of those cases where the
-    // DNS name is different but IP address remains the same.
-    String hostname = serverName.getHostname();
-    int port = serverName.getPort();
-    if (hostnameCanChange) {
-      try {
-        InetAddress ip = InetAddress.getByName(hostname);
-        return serviceName + "@" + hostname + "-" + ip.getHostAddress() + ":" + port;
-      } catch (UnknownHostException e) {
-        LOG.warn("Can not resolve " + hostname + ", please check your network", e);
-      }
-    }
-    return serviceName + "@" + hostname + ":" + port;
+  static int retries2Attempts(int retries) {
+    return Math.max(1, retries == Integer.MAX_VALUE ? Integer.MAX_VALUE : retries + 1);
   }
 
   static void checkHasFamilies(Mutation mutation) {

hbase-client/src/main/java/org/apache/hadoop/hbase/client/MetricsConnection.java

@@ -69,6 +69,8 @@ public class MetricsConnection implements StatisticTrackable {
   private static final String HEAP_BASE = "heapOccupancy_";
   private static final String CACHE_BASE = "cacheDroppingExceptions_";
   private static final String UNKNOWN_EXCEPTION = "UnknownException";
+  private static final String NS_LOOKUPS = "nsLookups";
+  private static final String NS_LOOKUPS_FAILED = "nsLookupsFailed";
   private static final String CLIENT_SVC = ClientService.getDescriptor().getName();
 
   /** A container class for collecting details about the RPC call as it percolates. */
@@ -293,6 +295,8 @@ public Counter newMetric(Class<?> clazz, String name, String scope) {
   protected final Timer userRegionLockWaitingTimer;
   protected final Timer userRegionLockHeldTimer;
   protected final Histogram userRegionLockQueueHist;
+  protected final Counter nsLookups;
+  protected final Counter nsLookupsFailed;
 
   // dynamic metrics
 
@@ -360,6 +364,8 @@ protected Ratio getRatio() {
       registry.timer(name(this.getClass(), "userRegionLockHeldDuration", scope));
     this.userRegionLockQueueHist =
       registry.histogram(name(MetricsConnection.class, "userRegionLockQueueLength", scope));
+    this.nsLookups = registry.counter(name(this.getClass(), NS_LOOKUPS, scope));
+    this.nsLookupsFailed = registry.counter(name(this.getClass(), NS_LOOKUPS_FAILED, scope));
 
     this.reporter = JmxReporter.forRegistry(this.registry).build();
     this.reporter.start();
@@ -564,4 +570,12 @@ public void incrCacheDroppingExceptions(Object exception) {
       CACHE_BASE + (exception == null ? UNKNOWN_EXCEPTION : exception.getClass().getSimpleName()),
       cacheDroppingExceptions, counterFactory).inc();
   }
+
+  public void incrNsLookups() {
+    this.nsLookups.inc();
+  }
+
+  public void incrNsLookupsFailed() {
+    this.nsLookupsFailed.inc();
+  }
 }