YARN-5309. Fix SSLFactory truststore reloader thread leak in TimelineClientImpl. Contributed by Weiwei Yang.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/pom.xml

@@ -150,6 +150,11 @@
       <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.bouncycastle</groupId>
+      <artifactId>bcprov-jdk16</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>com.sun.jersey.jersey-test-framework</groupId>
       <artifactId>jersey-test-framework-grizzly2</artifactId>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/client/api/impl/TimelineClientImpl.java

@@ -125,6 +125,7 @@ public class TimelineClientImpl extends TimelineClient {
   private Configuration configuration;
   private float timelineServiceVersion;
   private TimelineWriter timelineWriter;
+  private SSLFactory sslFactory;
 
   private volatile String timelineServiceAddress;
 
@@ -298,7 +299,7 @@ protected void serviceInit(Configuration conf) throws Exception {
     }
     ClientConfig cc = new DefaultClientConfig();
     cc.getClasses().add(YarnJacksonJaxbJsonProvider.class);
-    connConfigurator = newConnConfigurator(conf);
+    connConfigurator = initConnConfigurator(conf);
     if (UserGroupInformation.isSecurityEnabled()) {
       authenticator = new KerberosDelegationTokenAuthenticator();
     } else {
@@ -373,6 +374,9 @@ protected void serviceStop() throws Exception {
     if (timelineServiceV2) {
       entityDispatcher.stop();
     }
+    if (this.sslFactory != null) {
+      this.sslFactory.destroy();
+    }
     super.serviceStop();
   }
 
@@ -672,9 +676,9 @@ public HttpURLConnection getHttpURLConnection(final URL url) throws IOException
 
   }
 
-  private static ConnectionConfigurator newConnConfigurator(Configuration conf) {
+  private ConnectionConfigurator initConnConfigurator(Configuration conf) {
     try {
-      return newSslConnConfigurator(DEFAULT_SOCKET_TIMEOUT, conf);
+      return initSslConnConfigurator(DEFAULT_SOCKET_TIMEOUT, conf);
     } catch (Exception e) {
       LOG.debug("Cannot load customized ssl related configuration. " +
           "Fallback to system-generic settings.", e);
@@ -692,16 +696,15 @@ public HttpURLConnection configure(HttpURLConnection conn)
     }
   };
 
-  private static ConnectionConfigurator newSslConnConfigurator(final int timeout,
+  private ConnectionConfigurator initSslConnConfigurator(final int timeout,
       Configuration conf) throws IOException, GeneralSecurityException {
-    final SSLFactory factory;
     final SSLSocketFactory sf;
     final HostnameVerifier hv;
 
-    factory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
+    sslFactory = new SSLFactory(SSLFactory.Mode.CLIENT, conf);
-    factory.init();
+    sslFactory.init();
-    sf = factory.createSSLSocketFactory();
+    sf = sslFactory.createSSLSocketFactory();
-    hv = factory.getHostnameVerifier();
+    hv = sslFactory.getHostnameVerifier();
 
     return new ConnectionConfigurator() {
       @Override

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/test/java/org/apache/hadoop/yarn/client/api/impl/TestTimelineClient.java

@@ -25,6 +25,7 @@
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.when;
 
+import java.io.File;
 import java.io.IOException;
 import java.net.ConnectException;
 import java.net.SocketTimeoutException;
@@ -35,8 +36,10 @@
 import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.security.ssl.KeyStoreTestUtil;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.security.token.delegation.AbstractDelegationTokenSecretManager;
+import org.apache.hadoop.test.TestGenericTestUtils;
 import org.apache.hadoop.yarn.api.records.timeline.TimelineDomain;
 import org.apache.hadoop.yarn.api.records.timeline.TimelineEntities;
 import org.apache.hadoop.yarn.api.records.timeline.TimelineEntity;
@@ -434,6 +437,50 @@ private TimelineClientImpl createTimelineClientFakeTimelineClientRetryOp(
     return client;
   }
 
+  @Test
+  public void testTimelineClientCleanup() throws Exception {
+    YarnConfiguration conf = new YarnConfiguration();
+    conf.setBoolean(YarnConfiguration.TIMELINE_SERVICE_ENABLED, true);
+    conf.setInt(YarnConfiguration.TIMELINE_SERVICE_CLIENT_MAX_RETRIES, 0);
+
+    File testDir = TestGenericTestUtils.getTestDir();
+    String sslConfDir =
+        KeyStoreTestUtil.getClasspathDir(TestTimelineClient.class);
+    KeyStoreTestUtil.setupSSLConfig(testDir.getAbsolutePath(),
+        sslConfDir, conf, false);
+    client = createTimelineClient(conf);
+
+    ThreadGroup threadGroup = Thread.currentThread().getThreadGroup();
+
+    while (threadGroup.getParent() != null) {
+      threadGroup = threadGroup.getParent();
+    }
+
+    Thread[] threads = new Thread[threadGroup.activeCount()];
+
+    threadGroup.enumerate(threads);
+    Thread reloaderThread = null;
+    for (Thread thread : threads) {
+      if ((thread.getName() != null)
+          && (thread.getName().contains("Truststore reloader thread"))) {
+        reloaderThread = thread;
+      }
+    }
+    Assert.assertTrue("Reloader is not alive", reloaderThread.isAlive());
+
+    client.close();
+
+    boolean reloaderStillAlive = true;
+    for (int i = 0; i < 10; i++) {
+      reloaderStillAlive = reloaderThread.isAlive();
+      if (!reloaderStillAlive) {
+        break;
+      }
+      Thread.sleep(1000);
+    }
+    Assert.assertFalse("Reloader is still alive", reloaderStillAlive);
+  }
+
   private static class TestTimlineDelegationTokenSecretManager extends
       AbstractDelegationTokenSecretManager<TimelineDelegationTokenIdentifier> {