YARN.11590. RM process stuck after calling confStore.format() when ZK SSL/TLS is enabled, as netty thread waits indefinitely. Contributed by Ferenc Erdelyi

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ResourceManager.java

@@ -1903,10 +1903,11 @@ public class ResourceManager extends CompositeService
     }
 
     if (scheduler instanceof MutableConfScheduler && isConfigurationMutable) {
-      YarnConfigurationStore confStore = YarnConfigurationStoreFactory
-          .getStore(conf);
-      confStore.initialize(conf, conf, rmContext);
-      confStore.format();
+      try (YarnConfigurationStore confStore = YarnConfigurationStoreFactory
+          .getStore(conf)) {
+        confStore.initialize(conf, conf, rmContext);
+        confStore.format();
+      }
     } else {
       System.out.println(String.format("Scheduler Configuration format only " +
           "supported by %s.", MutableConfScheduler.class.getSimpleName()));

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/conf/YarnConfigurationStore.java

@@ -44,7 +44,7 @@ import java.util.Map;
  * {@code getPendingMutations}, and replay/confirm them via
  * {@code confirmMutation} as in the normal case.
  */
-public abstract class YarnConfigurationStore {
+public abstract class YarnConfigurationStore implements AutoCloseable {
 
   public static final Logger LOG =
       LoggerFactory.getLogger(YarnConfigurationStore.class);