HBASE-20775 TestMultiParallel is flakey

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java

@@ -799,6 +799,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
       s.setConsistency(Consistency.TIMELINE);
     }
     int maxAttempts = (retry ? numTries : 1);
+    boolean relocateMeta = false;
     for (int tries = 0; ; tries++) {
       if (tries >= maxAttempts) {
         throw new NoServerForRegionException("Unable to find region for "
@@ -825,6 +826,10 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
             return locations;
           }
         }
+        if (relocateMeta) {
+          relocateRegion(TableName.META_TABLE_NAME, HConstants.EMPTY_START_ROW,
+            RegionInfo.DEFAULT_REPLICA_ID);
+        }
         s.resetMvccReadPoint();
         try (ReversedClientScanner rcs =
           new ReversedClientScanner(conf, s, TableName.META_TABLE_NAME, this, rpcCallerFactory,
@@ -904,10 +909,8 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
           throw e;
         }
         // Only relocate the parent region if necessary
-        if(!(e instanceof RegionOfflineException ||
-            e instanceof NoServerForRegionException)) {
-          relocateRegion(TableName.META_TABLE_NAME, metaStartKey, replicaId);
-        }
+        relocateMeta =
+          !(e instanceof RegionOfflineException || e instanceof NoServerForRegionException);
       } finally {
         userRegionLock.unlock();
       }

hbase-server/pom.xml

@@ -19,6 +19,7 @@
  * limitations under the License.
  */
 -->
+<!-- for testing -->
   <modelVersion>4.0.0</modelVersion>
   <parent>
     <artifactId>hbase-build-configuration</artifactId>

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestMultiParallel.java

@@ -47,7 +47,6 @@ import org.apache.hadoop.hbase.coprocessor.MasterCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.MasterCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.MasterObserver;
 import org.apache.hadoop.hbase.coprocessor.ObserverContext;
-import org.apache.hadoop.hbase.master.LoadBalancer;
 import org.apache.hadoop.hbase.master.RegionPlan;
 import org.apache.hadoop.hbase.testclassification.FlakeyTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -85,7 +84,8 @@ public class TestMultiParallel {
   private static final int slaves = 5; // also used for testing HTable pool size
   private static Connection CONNECTION;
 
-  @BeforeClass public static void beforeClass() throws Exception {
+  @BeforeClass
+  public static void beforeClass() throws Exception {
     // Uncomment the following lines if more verbosity is needed for
     // debugging (see HBASE-12285 for details).
     //((Log4JLogger)RpcServer.LOG).getLogger().setLevel(Level.ALL);
@@ -93,7 +93,8 @@ public class TestMultiParallel {
     //((Log4JLogger)ScannerCallable.LOG).getLogger().setLevel(Level.ALL);
     UTIL.getConfiguration().set(HConstants.RPC_CODEC_CONF_KEY,
         KeyValueCodec.class.getCanonicalName());
-    UTIL.getConfiguration().setBoolean(LoadBalancer.TABLES_ON_MASTER, true);
+    // Disable table on master for now as the feature is broken
+    //UTIL.getConfiguration().setBoolean(LoadBalancer.TABLES_ON_MASTER, true);
     // We used to ask for system tables on Master exclusively but not needed by test and doesn't
     // work anyways -- so commented out.
     // UTIL.getConfiguration().setBoolean(LoadBalancer.SYSTEM_TABLES_ON_MASTER, true);
@@ -107,12 +108,14 @@ public class TestMultiParallel {
     assertTrue(MyMasterObserver.start.get());
   }
 
-  @AfterClass public static void afterClass() throws Exception {
+  @AfterClass
+  public static void afterClass() throws Exception {
     CONNECTION.close();
     UTIL.shutdownMiniCluster();
   }
 
-  @Before public void before() throws Exception {
+  @Before
+  public void before() throws Exception {
     final int balanceCount = MyMasterObserver.postBalanceCount.get();
     LOG.info("before");
     if (UTIL.ensureSomeRegionServersAvailable(slaves)) {
@@ -172,11 +175,8 @@ public class TestMultiParallel {
    * This is for testing the active number of threads that were used while
    * doing a batch operation. It inserts one row per region via the batch
    * operation, and then checks the number of active threads.
+   * <p/>
    * For HBASE-3553
-   * @throws IOException
-   * @throws InterruptedException
-   * @throws NoSuchFieldException
-   * @throws SecurityException
    */
   @Test
   public void testActiveThreadsCount() throws Exception {
@@ -280,8 +280,6 @@ public class TestMultiParallel {
   /**
    * Only run one Multi test with a forced RegionServer abort. Otherwise, the
    * unit tests will take an unnecessarily long time to run.
-   *
-   * @throws Exception
    */
   @Test
   public void testFlushCommitsWithAbort() throws Exception {
@@ -292,7 +290,6 @@ public class TestMultiParallel {
   /**
    * Set table auto flush to false and test flushing commits
    * @param doAbort true if abort one regionserver in the testing
-   * @throws Exception
    */
   private void doTestFlushCommits(boolean doAbort) throws Exception {
     // Load the data
@@ -342,9 +339,9 @@ public class TestMultiParallel {
       UTIL.waitFor(15 * 1000, new Waiter.Predicate<Exception>() {
         @Override
         public boolean evaluate() throws Exception {
-          // Master is also a regionserver, so the count is liveRScount
+          // We disable regions on master so the count should be liveRScount - 1
           return UTIL.getMiniHBaseCluster().getMaster()
-              .getClusterMetrics().getLiveServerMetrics().size() == liveRScount;
+              .getClusterMetrics().getLiveServerMetrics().size() == liveRScount - 1;
         }
       });
       UTIL.waitFor(15 * 1000, UTIL.predicateNoRegionsInTransition());
@@ -678,12 +675,12 @@ public class TestMultiParallel {
     RowMutations rm = new RowMutations(KEYS[50]);
     put = new Put(KEYS[50]);
     put.addColumn(BYTES_FAMILY, qual2, val2);
-    rm.add(put);
+    rm.add((Mutation) put);
     byte[] qual3 = Bytes.toBytes("qual3");
     byte[] val3 = Bytes.toBytes("putvalue3");
     put = new Put(KEYS[50]);
     put.addColumn(BYTES_FAMILY, qual3, val3);
-    rm.add(put);
+    rm.add((Mutation) put);
     actions.add(rm);
 
     // 7 Add another Get to the mixed sequence after RowMutations