HDFS-7314. When the DFSClient lease cannot be renewed, abort open-for-write files rather than the entire DFSClient. (mingma)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -165,6 +165,9 @@ Trunk (Unreleased)
     HDFS-5033. Bad error message for fs -put/copyFromLocal if user
     doesn't have permissions to read the source (Darrell Taylor via aw)
 
+    HDFS-7314. When the DFSClient lease cannot be renewed, abort open-for-write
+    files rather than the entire DFSClient. (mingma)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSClient.java

@@ -568,22 +568,8 @@ void closeConnectionToNamenode() {
     RPC.stopProxy(namenode);
   }
 
-  /** Abort and release resources held.  Ignore all errors. */
-  public void abort() {
-    clientRunning = false;
-    closeAllFilesBeingWritten(true);
-    try {
-      // remove reference to this client and stop the renewer,
-      // if there is no more clients under the renewer.
-      getLeaseRenewer().closeClient(this);
-    } catch (IOException ioe) {
-       LOG.info("Exception occurred while aborting the client " + ioe);
-    }
-    closeConnectionToNamenode();
-  }
-
   /** Close/abort all files being written. */
-  private void closeAllFilesBeingWritten(final boolean abort) {
+  public void closeAllFilesBeingWritten(final boolean abort) {
     for(;;) {
       final long inodeId;
       final DFSOutputStream out;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/client/impl/LeaseRenewer.java

@@ -215,6 +215,12 @@ private synchronized long getRenewalTime() {
     return renewal;
   }
 
+  /** Used for testing only. */
+  @VisibleForTesting
+  public synchronized void setRenewalTime(final long renewal) {
+    this.renewal = renewal;
+  }
+
   /** Add a client. */
   private synchronized void addClient(final DFSClient dfsc) {
     for(DFSClient c : dfsclients) {
@@ -453,8 +459,12 @@ private void run(final int id) throws InterruptedException {
               + (elapsed/1000) + " seconds.  Aborting ...", ie);
           synchronized (this) {
             while (!dfsclients.isEmpty()) {
-              dfsclients.get(0).abort();
+              DFSClient dfsClient = dfsclients.get(0);
+              dfsClient.closeAllFilesBeingWritten(true);
+              closeClient(dfsClient);
             }
+            //Expire the current LeaseRenewer thread.
+            emptyTime = 0;
           }
           break;
         } catch (IOException ie) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java

@@ -31,6 +31,7 @@
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.timeout;
 import static org.mockito.Mockito.when;
 
 import java.io.FileNotFoundException;
@@ -62,6 +63,7 @@
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys;
+import org.apache.hadoop.hdfs.client.impl.LeaseRenewer;
 import org.apache.hadoop.hdfs.client.HdfsUtils;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.ClientDatanodeProtocol;
@@ -355,6 +357,58 @@ public void testFailuresArePerOperation() throws Exception
     }
   }
 
+  /**
+   * Test DFSClient can continue to function after renewLease RPC
+   * receives SocketTimeoutException.
+   */
+  @Test
+  public void testLeaseRenewSocketTimeout() throws Exception
+  {
+    String file1 = "/testFile1";
+    String file2 = "/testFile2";
+    // Set short retry timeouts so this test runs faster
+    conf.setInt(DFSConfigKeys.DFS_CLIENT_RETRY_WINDOW_BASE, 10);
+    conf.setInt(DFS_CLIENT_SOCKET_TIMEOUT_KEY, 2 * 1000);
+    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
+    try {
+      cluster.waitActive();
+      NamenodeProtocols spyNN = spy(cluster.getNameNodeRpc());
+      Mockito.doThrow(new SocketTimeoutException()).when(spyNN).renewLease(
+          Mockito.anyString());
+      DFSClient client = new DFSClient(null, spyNN, conf, null);
+      // Get hold of the lease renewer instance used by the client
+      LeaseRenewer leaseRenewer = client.getLeaseRenewer();
+      leaseRenewer.setRenewalTime(100);
+      OutputStream out1 = client.create(file1, false);
+
+      Mockito.verify(spyNN, timeout(10000).times(1)).renewLease(
+          Mockito.anyString());
+      verifyEmptyLease(leaseRenewer);
+      try {
+        out1.write(new byte[256]);
+        fail("existing output stream should be aborted");
+      } catch (IOException e) {
+      }
+
+      // Verify DFSClient can do read operation after renewLease aborted.
+      client.exists(file2);
+      // Verify DFSClient can do write operation after renewLease no longer
+      // throws SocketTimeoutException.
+      Mockito.doNothing().when(spyNN).renewLease(
+          Mockito.anyString());
+      leaseRenewer = client.getLeaseRenewer();
+      leaseRenewer.setRenewalTime(100);
+      OutputStream out2 = client.create(file2, false);
+      Mockito.verify(spyNN, timeout(10000).times(2)).renewLease(
+          Mockito.anyString());
+      out2.write(new byte[256]);
+      out2.close();
+      verifyEmptyLease(leaseRenewer);
+    } finally {
+      cluster.shutdown();
+    }
+  }
+
   /**
    * Test that getAdditionalBlock() and close() are idempotent. This allows
    * a client to safely retry a call and still produce a correct
@@ -674,6 +728,14 @@ private boolean busyTest(int xcievers, int threads, int fileLen, int timeWin, in
     return ret;
   }
 
+  private void verifyEmptyLease(LeaseRenewer leaseRenewer) throws Exception {
+    int sleepCount = 0;
+    while (!leaseRenewer.isEmpty() && sleepCount++ < 20) {
+      Thread.sleep(500);
+    }
+    assertTrue("Lease should be empty.", leaseRenewer.isEmpty());
+  }
+
   class DFSClientReader implements Runnable {
     
     DFSClient client;