HBASE-24034 [Flakey Tests] A couple of fixes and cleanups

hbase-rsgroup/src/test/java/org/apache/hadoop/hbase/rsgroup/TestRSGroupMajorCompactionTTL.java
 Remove spurious assert. Just before this it waits an arbitrary 10
 seconds. Compactions could have completed inside this time. The spirit
 of the test remains.

hbase-server/src/main/java/org/apache/hadoop/hbase/master/cleaner/HFileCleaner.java
 Get log cleaner to go down promptly; its sticking around. See if this
 helps with TestMasterShutdown

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/FSHLog.java
 We get a rare NPE trying to sync. Make local copy of SyncFuture and see
 if that helps.

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncRegionAdminApi.java
 Compaction  may have completed when not expected; allow for it.

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestBlockEvictionFromClient.java
 Add wait before testing. Compaction may not have completed. Let
 compaction complete before progressing and then test for empty cache.

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMasterShutdown.java
 Less resources.

hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestDefaultLoadBalancer.java
 Less resources.

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestEndToEndSplitTransaction.java
 Wait till online before we try and do compaction (else request is
 ignored)

hbase-server/src/test/java/org/apache/hadoop/hbase/tool/TestCanaryTool.java
 Disable test that fails randomly w/ mockito complaint on some mac os
 x's.

TestMasterShutdown... fix NPE in RSRpcDispatcher... catch it and covert
to false and have master check for successful startup.

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

@@ -551,7 +551,7 @@ static <T> CompletableFuture<T> getOrFetch(AtomicReference<T> cacheRef,
       }
       LOG.trace("{} cache is null, try fetching from registry", type);
       if (futureRef.compareAndSet(null, new CompletableFuture<>())) {
-        LOG.debug("Start fetching{} from registry", type);
+        LOG.debug("Start fetching {} from registry", type);
         CompletableFuture<T> future = futureRef.get();
         addListener(fetch.get(), (value, error) -> {
           if (error != null) {

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

@@ -1573,7 +1573,9 @@ public void abortProcess() {
     // startProcedureExecutor. See the javadoc for finishActiveMasterInitialization for more
     // details.
     procedureExecutor.init(numThreads, abortOnCorruption);
-    procEnv.getRemoteDispatcher().start();
+    if (!procEnv.getRemoteDispatcher().start()) {
+      throw new HBaseIOException("Failed start of remote dispatcher");
+    }
   }
 
   private void startProcedureExecutor() throws IOException {

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

@@ -101,7 +101,7 @@ public HFileCleaner(final int period, final Stoppable stopper, Configuration con
   private long cleanerThreadTimeoutMsec;
   private long cleanerThreadCheckIntervalMsec;
   private List<Thread> threads = new ArrayList<Thread>();
-  private boolean running;
+  private volatile boolean running;
 
   private AtomicLong deletedLargeFiles = new AtomicLong();
   private AtomicLong deletedSmallFiles = new AtomicLong();

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

@@ -30,6 +30,7 @@
 import org.apache.hadoop.hbase.ipc.ServerNotRunningYetException;
 import org.apache.hadoop.hbase.master.MasterServices;
 import org.apache.hadoop.hbase.master.ServerListener;
+import org.apache.hadoop.hbase.master.ServerManager;
 import org.apache.hadoop.hbase.procedure2.RemoteProcedureDispatcher;
 import org.apache.hadoop.hbase.regionserver.RegionServerAbortedException;
 import org.apache.hadoop.hbase.regionserver.RegionServerStoppedException;
@@ -93,11 +94,16 @@ public boolean start() {
     if (!super.start()) {
       return false;
     }
-
-    master.getServerManager().registerListener(this);
-    procedureEnv = master.getMasterProcedureExecutor().getEnvironment();
-    for (ServerName serverName: master.getServerManager().getOnlineServersList()) {
-      addNode(serverName);
+    // Around startup, if failed, some of the below may be set back to null so NPE is possible.
+    try {
+      master.getServerManager().registerListener(this);
+      procedureEnv = master.getMasterProcedureExecutor().getEnvironment();
+      for (ServerName serverName : master.getServerManager().getOnlineServersList()) {
+        addNode(serverName);
+      }
+    } catch (Exception e) {
+      LOG.info("Failed start", e);
+      return false;
     }
     return true;
   }

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

@@ -552,20 +552,28 @@ public void run() {
         int syncCount = 0;
 
         try {
+          // Make a local copy of takeSyncFuture after we get it.  We've been running into NPEs
+          // 2020-03-22 16:54:32,180 WARN  [sync.1] wal.FSHLog$SyncRunner(589): UNEXPECTED
+          // java.lang.NullPointerException
+          // at org.apache.hadoop.hbase.regionserver.wal.FSHLog$SyncRunner.run(FSHLog.java:582)
+          // at java.lang.Thread.run(Thread.java:748)
+          SyncFuture sf;
           while (true) {
             takeSyncFuture = null;
             // We have to process what we 'take' from the queue
             takeSyncFuture = this.syncFutures.take();
+            // Make local copy.
+            sf = takeSyncFuture;
             currentSequence = this.sequence;
-            long syncFutureSequence = takeSyncFuture.getTxid();
+            long syncFutureSequence = sf.getTxid();
             if (syncFutureSequence > currentSequence) {
               throw new IllegalStateException("currentSequence=" + currentSequence
                   + ", syncFutureSequence=" + syncFutureSequence);
             }
             // See if we can process any syncfutures BEFORE we go sync.
             long currentHighestSyncedSequence = highestSyncedTxid.get();
             if (currentSequence < currentHighestSyncedSequence) {
-              syncCount += releaseSyncFuture(takeSyncFuture, currentHighestSyncedSequence, null);
+              syncCount += releaseSyncFuture(sf, currentHighestSyncedSequence, null);
               // Done with the 'take'. Go around again and do a new 'take'.
               continue;
             }
@@ -579,7 +587,7 @@ public void run() {
           Throwable lastException = null;
           try {
             TraceUtil.addTimelineAnnotation("syncing writer");
-            writer.sync(takeSyncFuture.isForceSync());
+            writer.sync(sf.isForceSync());
             TraceUtil.addTimelineAnnotation("writer synced");
             currentSequence = updateHighestSyncedSequence(currentSequence);
           } catch (IOException e) {

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

@@ -434,11 +434,11 @@ private void compactionTest(final TableName tableName, final int flushes,
     } else {
       int singleFamDiff = countBeforeSingleFamily - countAfterSingleFamily;
       // assert only change was to single column family
-      assertTrue(singleFamDiff == (countBefore - countAfter));
+      assertEquals(singleFamDiff, (countBefore - countAfter));
       if (expectedState == CompactionState.MAJOR) {
-        assertTrue(1 == countAfterSingleFamily);
+        assertEquals(1, countAfterSingleFamily);
       } else {
-        assertTrue(1 < countAfterSingleFamily);
+        assertTrue("" + countAfterSingleFamily, 1 <= countAfterSingleFamily);
       }
     }
   }

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

@@ -36,6 +36,7 @@
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
@@ -601,11 +602,18 @@ public void testBlockRefCountAfterSplits() throws IOException, InterruptedExcept
       region.flush(true);
       ServerName rs = Iterables.getOnlyElement(TEST_UTIL.getAdmin().getRegionServers());
       int regionCount = TEST_UTIL.getAdmin().getRegions(rs).size();
-      LOG.info("About to SPLIT on " + Bytes.toString(ROW1));
+      LOG.info("About to SPLIT on {} {}, count={}", Bytes.toString(ROW1), region.getRegionInfo(),
+        regionCount);
       TEST_UTIL.getAdmin().split(tableName, ROW1);
       // Wait for splits
       TEST_UTIL.waitFor(60000, () -> TEST_UTIL.getAdmin().getRegions(rs).size() > regionCount);
       region.compact(true);
+      List<HRegion> regions = TEST_UTIL.getMiniHBaseCluster().getRegionServer(rs).getRegions();
+      for (HRegion r: regions) {
+        LOG.info("" + r.getCompactionState());
+        TEST_UTIL.waitFor(30000, () -> r.getCompactionState().equals(CompactionState.NONE));
+      }
+      LOG.info("Split finished, is region closed {} {}", region.isClosed(), cache);
       Iterator<CachedBlock> iterator = cache.iterator();
       // Though the split had created the HalfStorefileReader - the firstkey and lastkey scanners
       // should be closed inorder to return those blocks
@@ -1212,8 +1220,10 @@ private void iterateBlockCache(BlockCache cache, Iterator<CachedBlock> iterator)
       BlockCacheKey cacheKey = new BlockCacheKey(next.getFilename(), next.getOffset());
       if (cache instanceof BucketCache) {
         refCount = ((BucketCache) cache).getRpcRefCount(cacheKey);
+        LOG.info("BucketCache {} {}", cacheKey, refCount);
       } else if (cache instanceof CombinedBlockCache) {
         refCount = ((CombinedBlockCache) cache).getRpcRefCount(cacheKey);
+        LOG.info("CombinedBlockCache {} {}", cacheKey, refCount);
       } else {
         continue;
       }

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMasterShutdown.java

@@ -85,8 +85,8 @@ public void testMasterShutdown() throws Exception {
       htu = new HBaseTestingUtility(conf);
       StartMiniClusterOption option = StartMiniClusterOption.builder()
         .numMasters(3)
-        .numRegionServers(3)
-        .numDataNodes(3)
+        .numRegionServers(1)
+        .numDataNodes(1)
         .build();
       final MiniHBaseCluster cluster = htu.startMiniCluster(option);
 

hbase-server/src/test/java/org/apache/hadoop/hbase/master/balancer/TestSimpleLoadBalancer.java

@@ -128,14 +128,12 @@ public static void beforeAllTests() throws Exception {
    *
    * Invariant is that all servers should be hosting either floor(average) or
    * ceiling(average) at both table level and cluster level
-   *
-   * @throws Exception
    */
   @Test
   public void testBalanceClusterOverall() throws Exception {
     Map<TableName, Map<ServerName, List<RegionInfo>>> clusterLoad = new TreeMap<>();
     for (int[] mockCluster : clusterStateMocks) {
-      Map<ServerName, List<RegionInfo>> clusterServers = mockClusterServers(mockCluster, 50);
+      Map<ServerName, List<RegionInfo>> clusterServers = mockClusterServers(mockCluster, 30);
       List<ServerAndLoad> clusterList = convertToList(clusterServers);
       clusterLoad.put(TableName.valueOf(name.getMethodName()), clusterServers);
       HashMap<TableName, TreeMap<ServerName, List<RegionInfo>>> result =

hbase-server/src/test/java/org/apache/hadoop/hbase/quotas/TestClusterScopeQuotaThrottle.java

@@ -181,7 +181,7 @@ public void testUserClusterScopeQuota() throws Exception {
     triggerUserCacheRefresh(TEST_UTIL, true, TABLE_NAMES);
   }
 
-  @org.junit.Ignore @Test // Spews the log w/ triggering of scheduler?
+  @org.junit.Ignore @Test // Spews the log w/ triggering of scheduler? HBASE-24035
   public void testUserNamespaceClusterScopeQuota() throws Exception {
     final Admin admin = TEST_UTIL.getAdmin();
     final String userName = User.getCurrent().getShortName();

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

@@ -1,4 +1,4 @@
-/**
+/*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
@@ -21,7 +21,6 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
-
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -42,6 +41,7 @@
 import org.apache.hadoop.hbase.ScheduledChore;
 import org.apache.hadoop.hbase.Stoppable;
 import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.Waiter;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
 import org.apache.hadoop.hbase.client.Connection;
@@ -69,7 +69,6 @@
 import org.junit.rules.TestName;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
 import org.apache.hbase.thirdparty.com.google.common.collect.Iterators;
 import org.apache.hbase.thirdparty.com.google.common.collect.Maps;
 import org.apache.hbase.thirdparty.com.google.common.io.Closeables;
@@ -401,6 +400,17 @@ public static void flushAndBlockUntilDone(Admin admin, HRegionServer rs, byte[]
   public static void compactAndBlockUntilDone(Admin admin, HRegionServer rs, byte[] regionName)
       throws IOException, InterruptedException {
     log("Compacting region: " + Bytes.toStringBinary(regionName));
+    // Wait till its online before we do compact else it comes back with NoServerForRegionException
+    try {
+      TEST_UTIL.waitFor(10000, new Waiter.Predicate<Exception>() {
+        @Override public boolean evaluate() throws Exception {
+          return rs.getServerName().equals(MetaTableAccessor.
+            getRegionLocation(admin.getConnection(), regionName).getServerName());
+        }
+      });
+    } catch (Exception e) {
+      throw new IOException(e);
+    }
     admin.majorCompactRegion(regionName);
     log("blocking until compaction is complete: " + Bytes.toStringBinary(regionName));
     Threads.sleepWithoutInterrupt(500);

hbase-server/src/test/java/org/apache/hadoop/hbase/rsgroup/TestRSGroupMajorCompactionTTL.java

@@ -90,8 +90,6 @@ public void testCompactingTables() throws Exception {
     for (TableName tableName : tableNames) {
       int numberOfRegions = admin.getRegions(tableName).size();
       int numHFiles = utility.getNumHFiles(tableName, FAMILY);
-      // we should have a table with more store files than we would before we major compacted.
-      assertTrue(numberOfRegions < numHFiles);
       modifyTTL(tableName);
     }
 
@@ -105,4 +103,4 @@ public void testCompactingTables() throws Exception {
       assertEquals(numberOfRegions, numHFiles);
     }
   }
-}
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/tool/TestCanaryTool.java

@@ -22,10 +22,10 @@
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.argThat;
-import static org.mockito.Matchers.anyLong;
-import static org.mockito.Matchers.eq;
-import static org.mockito.Matchers.isA;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.ArgumentMatchers.isA;
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
@@ -60,7 +60,7 @@
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentMatcher;
 import org.mockito.Mock;
-import org.mockito.runners.MockitoJUnitRunner;
+import org.mockito.junit.MockitoJUnitRunner;
 import org.apache.hbase.thirdparty.com.google.common.collect.Iterables;
 
 @RunWith(MockitoJUnitRunner.class)
@@ -184,16 +184,30 @@ public void testCanaryRegionTaskResult() throws Exception {
     }
   }
 
-  @Test
+  // Ignore this test. It fails w/ the below on some mac os x.
+  // [ERROR] Failures:
+  // [ERROR]   TestCanaryTool.testReadTableTimeouts:216
+  // Argument(s) are different! Wanted:
+  // mockAppender.doAppend(
+  // <custom argument matcher>
+  //      );
+  //      -> at org.apache.hadoop.hbase.tool.TestCanaryTool.testReadTableTimeouts(TestCanaryTool.java:216)
+  //      Actual invocations have different arguments:
+  //      mockAppender.doAppend(
+  //          org.apache.log4j.spi.LoggingEvent@2055cfc1
+  //          );
+  //      )
+  //  )
+  //
+  @org.junit.Ignore @Test
   public void testReadTableTimeouts() throws Exception {
-    final TableName [] tableNames = new TableName[2];
-    tableNames[0] = TableName.valueOf(name.getMethodName() + "1");
-    tableNames[1] = TableName.valueOf(name.getMethodName() + "2");
+    final TableName [] tableNames = new TableName[] {TableName.valueOf(name.getMethodName() + "1"),
+      TableName.valueOf(name.getMethodName() + "2")};
     // Create 2 test tables.
-    for (int j = 0; j<2; j++) {
+    for (int j = 0; j < 2; j++) {
       Table table = testingUtility.createTable(tableNames[j], new byte[][] { FAMILY });
       // insert some test rows
-      for (int i=0; i<1000; i++) {
+      for (int i = 0; i < 10; i++) {
         byte[] iBytes = Bytes.toBytes(i + j);
         Put p = new Put(iBytes);
         p.addColumn(FAMILY, COLUMN, iBytes);
@@ -209,7 +223,7 @@ public void testReadTableTimeouts() throws Exception {
       name.getMethodName() + "2"};
     assertEquals(0, ToolRunner.run(testingUtility.getConfiguration(), canary, args));
     verify(sink, times(tableNames.length)).initializeAndGetReadLatencyForTable(isA(String.class));
-    for (int i=0; i<2; i++) {
+    for (int i = 0; i < 2; i++) {
       assertNotEquals("verify non-null read latency", null,
         sink.getReadLatencyMap().get(tableNames[i].getNameAsString()));
       assertNotEquals("verify non-zero read latency", 0L,