Revert "HDFS-13388. RequestHedgingProxyProvider calls multiple configured NNs all the time. Contributed by Jinglun."

This reverts commit 1049e180a7dbc85e17c17240d231ed9a4659ed09.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/server/namenode/ha/RequestHedgingProxyProvider.java

@@ -76,20 +76,6 @@ public class RequestHedgingProxyProvider<T> extends
     public Object
     invoke(Object proxy, final Method method, final Object[] args)
             throws Throwable {
-      if (currentUsedProxy != null) {
-        try {
-          Object retVal = method.invoke(currentUsedProxy.proxy, args);
-          LOG.debug("Invocation successful on [{}]",
-              currentUsedProxy.proxyInfo);
-          return retVal;
-        } catch (InvocationTargetException ex) {
-          Exception unwrappedException = unwrapInvocationTargetException(ex);
-          logProxyException(unwrappedException, currentUsedProxy.proxyInfo);
-          LOG.trace("Unsuccessful invocation on [{}]",
-              currentUsedProxy.proxyInfo);
-          throw unwrappedException;
-        }
-      }
       Map<Future<Object>, ProxyInfo<T>> proxyMap = new HashMap<>();
       int numAttempts = 0;
 

hadoop-hdfs-project/hadoop-hdfs-client/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestRequestHedgingProxyProvider.java

@@ -42,15 +42,10 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
-
-import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
-import static org.junit.Assert.assertEquals;
 import org.mockito.Matchers;
 import org.mockito.Mockito;
 import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
-import static org.mockito.Mockito.when;
-import static org.mockito.Mockito.mock;
 
 import com.google.common.collect.Lists;
 
@@ -103,80 +98,6 @@ public class TestRequestHedgingProxyProvider {
     Mockito.verify(goodMock).getStats();
   }
 
-  @Test
-  public void testRequestNNAfterOneSuccess() throws Exception {
-    final AtomicInteger goodCount = new AtomicInteger(0);
-    final AtomicInteger badCount = new AtomicInteger(0);
-    final ClientProtocol goodMock = mock(ClientProtocol.class);
-    when(goodMock.getStats()).thenAnswer(new Answer<long[]>() {
-      @Override
-      public long[] answer(InvocationOnMock invocation) throws Throwable {
-        goodCount.incrementAndGet();
-        Thread.sleep(1000);
-        return new long[]{1};
-      }
-    });
-    final ClientProtocol badMock = mock(ClientProtocol.class);
-    when(badMock.getStats()).thenAnswer(new Answer<long[]>() {
-      @Override
-      public long[] answer(InvocationOnMock invocation) throws Throwable {
-        badCount.incrementAndGet();
-        throw new IOException("Bad mock !!");
-      }
-    });
-
-    RequestHedgingProxyProvider<ClientProtocol> provider =
-        new RequestHedgingProxyProvider<>(conf, nnUri, ClientProtocol.class,
-            createFactory(badMock, goodMock));
-    ClientProtocol proxy = provider.getProxy().proxy;
-    proxy.getStats();
-    assertEquals(1, goodCount.get());
-    assertEquals(1, badCount.get());
-    // We will only use the successful proxy after a successful invocation.
-    proxy.getStats();
-    assertEquals(2, goodCount.get());
-    assertEquals(1, badCount.get());
-  }
-
-  @Test
-  public void testExceptionInfo() throws Exception {
-    final ClientProtocol goodMock = mock(ClientProtocol.class);
-    when(goodMock.getStats()).thenAnswer(new Answer<long[]>() {
-      private boolean first = true;
-      @Override
-      public long[] answer(InvocationOnMock invocation)
-          throws Throwable {
-        if (first) {
-          Thread.sleep(1000);
-          first = false;
-          return new long[] {1};
-        } else {
-          throw new IOException("Expected Exception Info");
-        }
-      }
-    });
-    final ClientProtocol badMock = mock(ClientProtocol.class);
-    when(badMock.getStats()).thenAnswer(new Answer<long[]>() {
-      @Override
-      public long[] answer(InvocationOnMock invocation)
-          throws Throwable {
-        throw new IOException("Bad Mock! This is Standby!");
-      }
-    });
-
-    RequestHedgingProxyProvider<ClientProtocol> provider =
-        new RequestHedgingProxyProvider<>(conf, nnUri, ClientProtocol.class,
-            createFactory(badMock, goodMock));
-    ClientProtocol proxy = provider.getProxy().proxy;
-    proxy.getStats();
-    // Test getting the exception when the successful proxy encounters one.
-    try {
-      proxy.getStats();
-    } catch (IOException e) {
-      assertExceptionContains("Expected Exception Info", e);
-    }
-  }
-
   @Test
   public void testHedgingWhenOneIsSlow() throws Exception {
     final ClientProtocol goodMock = Mockito.mock(ClientProtocol.class);