HADOOP-18365. Update the remote address when a change is detected

Avoid reconnecting to the old address after detecting that the address has been updated.

Author: Steve Vaughan Jr

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ipc/Client.java

@@ -645,6 +645,8 @@ private synchronized boolean updateAddress() throws IOException {
         LOG.warn("Address change detected. Old: " + server.toString() +
                                  " New: " + currentAddr.toString());
         server = currentAddr;
+        // Update the remote address so that reconnections are with the updated address.  This avoids thrashing.
+        remoteId.setAddress(currentAddr);
         UserGroupInformation ticket = remoteId.getTicket();
         this.setName("IPC Client (" + socketFactory.hashCode()
             + ") connection to " + server.toString() + " from "
@@ -1753,7 +1755,16 @@ public ConnectionId(InetSocketAddress address, Class<?> protocol,
     InetSocketAddress getAddress() {
       return address;
     }
-    
+
+    /**
+     * Used to update the remote address when an address change is detected.
+     *
+     * @param address the new address
+     */
+    private void setAddress(InetSocketAddress address) {
+      this.address = address;
+    }
+
     Class<?> getProtocol() {
       return protocol;
     }