HBASE-22297 Addendum make TestSplitTransactionOnCluster more stable

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestSplitTransactionOnCluster.java

@@ -31,6 +31,7 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.hadoop.conf.Configuration;
@@ -511,17 +512,13 @@ public void testSplitShouldNotThrowNPEEvenARegionHasEmptySplitFiles() throws Exc
   }
 
   /**
-   * Verifies HBASE-5806.  Here the case is that splitting is completed but before the
-   * CJ could remove the parent region the master is killed and restarted.
-   * @throws IOException
-   * @throws InterruptedException
-   * @throws NodeExistsException
-   * @throws KeeperException
+   * Verifies HBASE-5806. Here the case is that splitting is completed but before the CJ could
+   * remove the parent region the master is killed and restarted.
    */
   @Test
   public void testMasterRestartAtRegionSplitPendingCatalogJanitor()
       throws IOException, InterruptedException, NodeExistsException,
-      KeeperException, ServiceException {
+      KeeperException, ServiceException, ExecutionException {
     final TableName tableName = TableName.valueOf(name.getMethodName());
 
     // Create table then get the single region for our new table.
@@ -542,7 +539,7 @@ public void testMasterRestartAtRegionSplitPendingCatalogJanitor()
       HRegionServer server = cluster.getRegionServer(tableRegionIndex);
       printOutRegions(server, "Initial regions: ");
       // Call split.
-      this.admin.splitRegionAsync(hri.getRegionName());
+      this.admin.splitRegionAsync(hri.getRegionName()).get();
       List<HRegion> daughters = checkAndGetDaughters(tableName);
 
       // Before cleanup, get a new master.