HDFS-4805. Webhdfs client is fragile to token renewal errors. Contributed by Daryn Sharp.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1482121 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/DelegationTokenRenewer.java

@@ -55,13 +55,14 @@ public class DelegationTokenRenewer
    * An action that will renew and replace the file system's delegation 
    * tokens automatically.
    */
-  private static class RenewAction<T extends FileSystem & Renewable>
+  public static class RenewAction<T extends FileSystem & Renewable>
       implements Delayed {
     /** when should the renew happen */
     private long renewalTime;
     /** a weak reference to the file system so that it can be garbage collected */
     private final WeakReference<T> weakFs;
     private Token<?> token; 
+    boolean isValid = true;
 
     private RenewAction(final T fs) {
       this.weakFs = new WeakReference<T>(fs);
@@ -69,6 +70,10 @@ public class DelegationTokenRenewer
       updateRenewalTime(renewCycle);
     }
  
+    public boolean isValid() {
+      return isValid;
+    }
+    
     /** Get the delay until this event should happen. */
     @Override
     public long getDelay(final TimeUnit unit) {
@@ -132,6 +137,7 @@ public class DelegationTokenRenewer
               updateRenewalTime(renewCycle);
               fs.setDelegationToken(token);
             } catch (IOException ie2) {
+              isValid = false;
               throw new IOException("Can't renew or get new delegation token ", ie);
             }
           }
@@ -160,7 +166,8 @@ public class DelegationTokenRenewer
   private static final long RENEW_CYCLE = 24 * 60 * 60 * 1000; 
 
   @InterfaceAudience.Private
-  protected static long renewCycle = RENEW_CYCLE;
+  @VisibleForTesting
+  public static long renewCycle = RENEW_CYCLE;
 
   /** Queue to maintain the RenewActions to be processed by the {@link #run()} */
   private volatile DelayQueue<RenewAction<?>> queue = new DelayQueue<RenewAction<?>>();
@@ -206,7 +213,7 @@ public class DelegationTokenRenewer
   
   /** Add a renew action to the queue. */
   @SuppressWarnings("static-access")
-  public <T extends FileSystem & Renewable> void addRenewAction(final T fs) {
+  public <T extends FileSystem & Renewable> RenewAction<T> addRenewAction(final T fs) {
     synchronized (this) {
       if (!isAlive()) {
         start();
@@ -218,6 +225,7 @@ public class DelegationTokenRenewer
     } else {
       fs.LOG.error("does not have a token for renewal");
     }
+    return action;
   }
 
   /**

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

@@ -3043,6 +3043,9 @@ Release 0.23.8 - UNRELEASED
     HDFS-4699. TestPipelinesFailover#testPipelineRecoveryStress fails
     sporadically (Chris Nauroth via kihwal)
 
+    HDFS-4805. Webhdfs client is fragile to token renewal errors 
+    (daryn via kihwal)
+
 Release 0.23.7 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -125,6 +125,8 @@ public class WebHdfsFileSystem extends FileSystem
       = new WebHdfsDelegationTokenSelector();
 
   private DelegationTokenRenewer dtRenewer = null;
+  @VisibleForTesting
+  DelegationTokenRenewer.RenewAction<?> action;
 
   @VisibleForTesting
   protected synchronized void addRenewAction(final WebHdfsFileSystem webhdfs) {
@@ -132,7 +134,7 @@ public class WebHdfsFileSystem extends FileSystem
       dtRenewer = DelegationTokenRenewer.getInstance();
     }
 
-    dtRenewer.addRenewAction(webhdfs);
+    action = dtRenewer.addRenewAction(webhdfs);
   }
 
   /** Is WebHDFS enabled in conf? */
@@ -200,7 +202,8 @@ public class WebHdfsFileSystem extends FileSystem
   }
 
   protected synchronized Token<?> getDelegationToken() throws IOException {
-    if (!hasInitedToken) {
+    // we haven't inited yet, or we used to have a token but it expired
+    if (!hasInitedToken || (action != null && !action.isValid())) {
       //since we don't already have a token, go get one
       Token<?> token = getDelegationToken(null);
       // security might be disabled

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHdfsTokens.java

@@ -27,6 +27,8 @@ import java.io.IOException;
 import java.net.URI;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.DelegationTokenRenewer;
+import org.apache.hadoop.fs.DelegationTokenRenewer.RenewAction;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
 import org.apache.hadoop.hdfs.web.resources.DeleteOpParam;
 import org.apache.hadoop.hdfs.web.resources.GetOpParam;
@@ -199,4 +201,50 @@ public class TestWebHdfsTokens {
       assertFalse(op.getRequireAuth());
     }
   }
+  
+  @Test
+  public void testGetTokenAfterFailure() throws Exception {
+    Configuration conf = mock(Configuration.class);
+    Token<?> token1 = mock(Token.class);
+    Token<?> token2 = mock(Token.class);
+    long renewCycle = 1000;
+    
+    DelegationTokenRenewer.renewCycle = renewCycle;
+    WebHdfsFileSystem fs = spy(new WebHdfsFileSystem());
+    doReturn(conf).when(fs).getConf();
+    doReturn(token1).doReturn(token2).when(fs).getDelegationToken(null);
+    // cause token renewer to abandon the token
+    doThrow(new IOException("renew failed")).when(token1).renew(conf);
+    doThrow(new IOException("get failed")).when(fs).addDelegationTokens(null, null);
+
+    // trigger token acquisition
+    Token<?> token = fs.getDelegationToken();
+    RenewAction<?> action = fs.action; 
+    assertSame(token1, token);
+    assertTrue(action.isValid());
+
+    // fetch again and make sure it's the same as before
+    token = fs.getDelegationToken();
+    assertSame(token1, token);
+    assertSame(action, fs.action);
+    assertTrue(fs.action.isValid());
+    
+    // upon renewal, token will go bad based on above stubbing
+    Thread.sleep(renewCycle);
+    assertSame(action, fs.action);
+    assertFalse(fs.action.isValid());
+    
+    // now that token is invalid, should get a new one
+    token = fs.getDelegationToken();
+    assertSame(token2, token);
+    assertNotSame(action, fs.action);
+    assertTrue(fs.action.isValid());
+    action = fs.action;
+    
+    // should get same one again
+    token = fs.getDelegationToken();
+    assertSame(token2, token);
+    assertSame(action, fs.action);
+    assertTrue(fs.action.isValid());
+  }
 }