HBASE-11709 TestMasterShutdown can fail sometime

hbase-server/src/main/java/org/apache/hadoop/hbase/master/AssignmentManager.java

@@ -644,11 +644,6 @@ public class AssignmentManager {
     if (isDisabledorDisablingRegionInRIT(region)) {
       return;
     }
-    if (this.serverManager.isClusterShutdown()) {
-      LOG.info("Cluster shutdown is set; skipping assign of " +
-        region.getRegionNameAsString());
-      return;
-    }
     String encodedName = region.getEncodedName();
     Lock lock = locker.acquireLock(encodedName);
     try {
@@ -2089,13 +2084,7 @@ public class AssignmentManager {
   }
 
   public void stop() {
-    shutdown(); // Stop executor service, etc
-  }
-
-  /**
-   * Shutdown the threadpool executor service
-   */
-  public void shutdown() {
+    // Shutdown the threadpool executor service
     threadPoolExecutorService.shutdownNow();
     regionStateStore.stop();
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -1632,20 +1632,18 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
         LOG.error("Error call master coprocessor preShutdown()", ioe);
       }
     }
-    if (this.assignmentManager != null) {
-      this.assignmentManager.shutdown();
-    }
-    try {
-      if (this.clusterStatusTracker != null){
-        this.clusterStatusTracker.setClusterDown();
+
     if (this.serverManager != null) {
       this.serverManager.shutdownCluster();
     }
-      }
+    if (this.clusterStatusTracker != null){
+      try {
+        this.clusterStatusTracker.setClusterDown();
       } catch (KeeperException e) {
         LOG.error("ZooKeeper exception trying to set cluster as down in ZK", e);
       }
     }
+  }
 
   public void stopMaster() {
     if (cpHost != null) {

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java

@@ -874,7 +874,7 @@ public class MasterRpcServices extends RSRpcServices
   public IsMasterRunningResponse isMasterRunning(RpcController c,
       IsMasterRunningRequest req) throws ServiceException {
     try {
-      master.checkInitialized();
+      master.checkServiceStarted();
       return IsMasterRunningResponse.newBuilder().setIsMasterRunning(
         !master.isStopped()).build();
     } catch (IOException e) {

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -670,7 +670,7 @@ public class HRegionServer extends HasThread implements
    * @return False if cluster shutdown in progress
    */
   private boolean isClusterUp() {
-    return this.clusterStatusTracker.isClusterUp();
+    return clusterStatusTracker != null && clusterStatusTracker.isClusterUp();
   }
 
   private void initializeThreads() throws IOException {