HADOOP-11368. Fix SSLFactory truststore reloader thread leak in KMSClientProvider. Contributed by Arun Suresh.

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

@@ -539,6 +539,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11369. Fix new findbugs warnings in hadoop-mapreduce-client,
     non-core directories. (Li Lu via wheat9)
 
+    HADOOP-11368. Fix SSLFactory truststore reloader thread leak in
+    KMSClientProvider. (Arun Suresh via wang)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/key/kms/KMSClientProvider.java

@@ -827,6 +827,10 @@ public class KMSClientProvider extends KeyProvider implements CryptoExtension,
       encKeyVersionQueue.shutdown();
     } catch (Exception e) {
       throw new IOException(e);
+    } finally {
+      if (sslFactory != null) {
+        sslFactory.destroy();
+      }
     }
   }
 }

hadoop-common-project/hadoop-kms/src/test/java/org/apache/hadoop/crypto/key/kms/server/TestKMS.java

@@ -303,6 +303,32 @@ public class TestKMS {
             url.getProtocol().equals("https"));
         final URI uri = createKMSUri(getKMSUrl());
 
+        if (ssl) {
+          KeyProvider testKp = new KMSClientProvider(uri, 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());
+          testKp.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);
+        }
+
         if (kerberos) {
           for (String user : new String[]{"client", "client/host"}) {
             doAs(user, new PrivilegedExceptionAction<Void>() {