HADOOP-8202. RPC stopProxy() does not close the proxy correctly. Contributed by Hari Mankude.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1305704 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -286,6 +286,9 @@ Release 0.23.3 - UNRELEASED
 
     HADOOP-8204. TestHealthMonitor fails occasionally (todd)
 
+    HADOOP-8202. RPC stopProxy() does not close the proxy correctly.
+    (Hari Mankude via suresh)
+
   BREAKDOWN OF HADOOP-7454 SUBTASKS
 
     HADOOP-7455. HA: Introduce HA Service Protocol Interface. (suresh)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/ha/HealthMonitor.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.ha;
 
+import java.io.Closeable;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.LinkedList;
@@ -194,7 +195,9 @@ class HealthMonitor {
       } catch (Throwable t) {
         LOG.warn("Transport-level exception trying to monitor health of " +
             targetToMonitor + ": " + t.getLocalizedMessage());
-        RPC.stopProxy(proxy);
+        if (proxy instanceof Closeable) {
+          RPC.stopProxy(proxy);
+        }
         proxy = null;
         enterState(State.SERVICE_NOT_RESPONDING);
         Thread.sleep(sleepAfterDisconnectMillis);

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

@@ -39,6 +39,7 @@ import javax.net.SocketFactory;
 
 import org.apache.commons.logging.*;
 
+import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.io.*;
 import org.apache.hadoop.ipc.Client.ConnectionId;
 import org.apache.hadoop.ipc.RpcPayloadHeader.RpcKind;
@@ -572,38 +573,41 @@ public class RPC {
   }
 
   /**
-   * Stop this proxy and release its invoker's resource by getting the
-   * invocation handler for the given proxy object and calling
-   * {@link Closeable#close} if that invocation handler implements
-   * {@link Closeable}.
+   * Stop the proxy. Proxy must either implement {@link Closeable} or must have
+   * associated {@link RpcInvocationHandler}.
    * 
-   * @param proxy the RPC proxy object to be stopped
+   * @param proxy
+   *          the RPC proxy object to be stopped
+   * @throws HadoopIllegalArgumentException
+   *           if the proxy does not implement {@link Closeable} interface or
+   *           does not have closeable {@link InvocationHandler}
    */
   public static void stopProxy(Object proxy) {
-    if (proxy instanceof ProtocolTranslator) {
-      RPC.stopProxy(((ProtocolTranslator)proxy)
-          .getUnderlyingProxyObject());
-      return;
+    if (proxy == null) {
+      throw new HadoopIllegalArgumentException(
+          "Cannot close proxy since it is null");
+    }
+    try {
+      if (proxy instanceof Closeable) {
+        ((Closeable) proxy).close();
+        return;
+      } else {
+        InvocationHandler handler = Proxy.getInvocationHandler(proxy);
+        if (handler instanceof Closeable) {
+          ((Closeable) handler).close();
+          return;
+        }
+      }
+    } catch (IOException e) {
+      LOG.error("Closing proxy or invocation handler caused exception", e);
+    } catch (IllegalArgumentException e) {
+      LOG.error("RPC.stopProxy called on non proxy.", e);
     }
     
-    InvocationHandler invocationHandler = null;
-    try {
-      invocationHandler = Proxy.getInvocationHandler(proxy);
-    } catch (IllegalArgumentException e) {
-      LOG.error("Tried to call RPC.stopProxy on an object that is not a proxy.", e);
-    }
-    if (proxy != null && invocationHandler != null &&
-        invocationHandler instanceof Closeable) {
-      try {
-        ((Closeable)invocationHandler).close();
-      } catch (IOException e) {
-        LOG.error("Stopping RPC invocation handler caused exception", e);
-      }
-    } else {
-      LOG.error("Could not get invocation handler " + invocationHandler +
-          " for proxy class " + (proxy == null ? null : proxy.getClass()) +
-          ", or invocation handler is not closeable.");
-    }
+    throw new HadoopIllegalArgumentException(
+        "Cannot close proxy - is not Closeable or "
+            + "does not provide closeable invocation handler "
+            + proxy.getClass());
   }
 
   /** 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/ipc/TestRPC.java

@@ -33,6 +33,7 @@ import java.util.Arrays;
 import javax.net.SocketFactory;
 
 import org.apache.commons.logging.*;
+import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.CommonConfigurationKeys;
 import org.apache.hadoop.io.UTF8;
@@ -584,9 +585,10 @@ public class TestRPC {
    * Test stopping a non-registered proxy
    * @throws Exception
    */
-  @Test
+  @Test(expected=HadoopIllegalArgumentException.class)
   public void testStopNonRegisteredProxy() throws Exception {
     RPC.stopProxy(mock(TestProtocol.class));
+    RPC.stopProxy(null);
   }
   
   @Test