Backport "HBASE-27903 Skip submitting Split/Merge procedure when split/merge is disabled at table level" to branch-2.6

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

@@ -2197,21 +2197,26 @@ public long mergeRegions(final RegionInfo[] regionsToMerge, final boolean forcib
     final long nonce) throws IOException {
     checkInitialized();
 
+    final String regionNamesToLog = RegionInfo.getShortNameToLog(regionsToMerge);
+
     if (!isSplitOrMergeEnabled(MasterSwitchType.MERGE)) {
-      String regionsStr = Arrays.deepToString(regionsToMerge);
-      LOG.warn("Merge switch is off! skip merge of " + regionsStr);
+      LOG.warn("Merge switch is off! skip merge of " + regionNamesToLog);
+      throw new DoNotRetryIOException(
+        "Merge of " + regionNamesToLog + " failed because merge switch is off");
+    }
+
+    if (!getTableDescriptors().get(regionsToMerge[0].getTable()).isMergeEnabled()) {
+      LOG.warn("Merge is disabled for the table! Skipping merge of {}", regionNamesToLog);
       throw new DoNotRetryIOException(
-        "Merge of " + regionsStr + " failed because merge switch is off");
+        "Merge of " + regionNamesToLog + " failed as region merge is disabled for the table");
     }
 
-    final String mergeRegionsStr = Arrays.stream(regionsToMerge).map(RegionInfo::getEncodedName)
-      .collect(Collectors.joining(", "));
     return MasterProcedureUtil.submitProcedure(new NonceProcedureRunnable(this, ng, nonce) {
       @Override
       protected void run() throws IOException {
         getMaster().getMasterCoprocessorHost().preMergeRegions(regionsToMerge);
         String aid = getClientIdAuditPrefix();
-        LOG.info("{} merge regions {}", aid, mergeRegionsStr);
+        LOG.info("{} merge regions {}", aid, regionNamesToLog);
         submitProcedure(new MergeTableRegionsProcedure(procedureExecutor.getEnvironment(),
           regionsToMerge, forcible));
         getMaster().getMasterCoprocessorHost().postMergeRegions(regionsToMerge);
@@ -2235,6 +2240,12 @@ public long splitRegion(final RegionInfo regionInfo, final byte[] splitRow, fina
         "Split region " + regionInfo.getRegionNameAsString() + " failed due to split switch off");
     }
 
+    if (!getTableDescriptors().get(regionInfo.getTable()).isSplitEnabled()) {
+      LOG.warn("Split is disabled for the table! Skipping split of {}", regionInfo);
+      throw new DoNotRetryIOException("Split region " + regionInfo.getRegionNameAsString()
+        + " failed as region split is disabled for the table");
+    }
+
     return MasterProcedureUtil
       .submitProcedure(new MasterProcedureUtil.NonceProcedureRunnable(this, nonceGroup, nonce) {
         @Override

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

@@ -444,35 +444,36 @@ protected ProcedureMetrics getProcedureMetrics(MasterProcedureEnv env) {
   private boolean prepareMergeRegion(final MasterProcedureEnv env) throws IOException {
     // Fail if we are taking snapshot for the given table
     TableName tn = regionsToMerge[0].getTable();
+    final String regionNamesToLog = RegionInfo.getShortNameToLog(regionsToMerge);
     if (env.getMasterServices().getSnapshotManager().isTableTakingAnySnapshot(tn)) {
-      throw new MergeRegionException("Skip merging regions "
-        + RegionInfo.getShortNameToLog(regionsToMerge) + ", because we are snapshotting " + tn);
+      throw new MergeRegionException(
+        "Skip merging regions " + regionNamesToLog + ", because we are snapshotting " + tn);
     }
 
-    // Mostly this check is not used because we already check the switch before submit a merge
-    // procedure. Just for safe, check the switch again. This procedure can be rollbacked if
-    // the switch was set to false after submit.
+    // Mostly the below two checks are not used because we already check the switches before
+    // submitting the merge procedure. Just for safety, we are checking the switch again here.
+    // Also, in case the switch was set to false after submission, this procedure can be rollbacked,
+    // thanks to this double check!
+    // case 1: check for cluster level switch
     if (!env.getMasterServices().isSplitOrMergeEnabled(MasterSwitchType.MERGE)) {
-      String regionsStr = Arrays.deepToString(this.regionsToMerge);
-      LOG.warn("Merge switch is off! skip merge of " + regionsStr);
+      LOG.warn("Merge switch is off! skip merge of " + regionNamesToLog);
       setFailure(getClass().getSimpleName(),
-        new IOException("Merge of " + regionsStr + " failed because merge switch is off"));
+        new IOException("Merge of " + regionNamesToLog + " failed because merge switch is off"));
       return false;
     }
-
+    // case 2: check for table level switch
     if (!env.getMasterServices().getTableDescriptors().get(getTableName()).isMergeEnabled()) {
-      String regionsStr = Arrays.deepToString(regionsToMerge);
-      LOG.warn("Merge is disabled for the table! Skipping merge of {}", regionsStr);
+      LOG.warn("Merge is disabled for the table! Skipping merge of {}", regionNamesToLog);
       setFailure(getClass().getSimpleName(), new IOException(
-        "Merge of " + regionsStr + " failed as region merge is disabled for the table"));
+        "Merge of " + regionNamesToLog + " failed as region merge is disabled for the table"));
       return false;
     }
 
     RegionStates regionStates = env.getAssignmentManager().getRegionStates();
     for (RegionInfo ri : this.regionsToMerge) {
       if (MetaTableAccessor.hasMergeRegions(env.getMasterServices().getConnection(), ri)) {
-        String msg = "Skip merging " + RegionInfo.getShortNameToLog(regionsToMerge)
-          + ", because a parent, " + RegionInfo.getShortNameToLog(ri) + ", has a merge qualifier "
+        String msg = "Skip merging " + regionNamesToLog + ", because a parent, "
+          + RegionInfo.getShortNameToLog(ri) + ", has a merge qualifier "
           + "(if a 'merge column' in parent, it was recently merged but still has outstanding "
           + "references to its parents that must be cleared before it can participate in merge -- "
           + "major compact it to hurry clearing of its references)";
@@ -492,8 +493,8 @@ private boolean prepareMergeRegion(final MasterProcedureEnv env) throws IOExcept
       try {
         if (!isMergeable(env, state)) {
           setFailure(getClass().getSimpleName(),
-            new MergeRegionException("Skip merging " + RegionInfo.getShortNameToLog(regionsToMerge)
-              + ", because a parent, " + RegionInfo.getShortNameToLog(ri) + ", is not mergeable"));
+            new MergeRegionException("Skip merging " + regionNamesToLog + ", because a parent, "
+              + RegionInfo.getShortNameToLog(ri) + ", is not mergeable"));
           return false;
         }
       } catch (IOException e) {

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

@@ -547,16 +547,18 @@ public boolean prepareSplitRegion(final MasterProcedureEnv env) throws IOExcepti
       return false;
     }
 
-    // Mostly this check is not used because we already check the switch before submit a split
-    // procedure. Just for safe, check the switch again. This procedure can be rollbacked if
-    // the switch was set to false after submit.
+    // Mostly the below two checks are not used because we already check the switches before
+    // submitting the split procedure. Just for safety, we are checking the switch again here.
+    // Also, in case the switch was set to false after submission, this procedure can be rollbacked,
+    // thanks to this double check!
+    // case 1: check for cluster level switch
     if (!env.getMasterServices().isSplitOrMergeEnabled(MasterSwitchType.SPLIT)) {
       LOG.warn("pid=" + getProcId() + " split switch is off! skip split of " + parentHRI);
       setFailure(new IOException(
         "Split region " + parentHRI.getRegionNameAsString() + " failed due to split switch off"));
       return false;
     }
-
+    // case 2: check for table level switch
     if (!env.getMasterServices().getTableDescriptors().get(getTableName()).isSplitEnabled()) {
       LOG.warn("pid={}, split is disabled for the table! Skipping split of {}", getProcId(),
         parentHRI);

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

@@ -21,18 +21,18 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import java.io.IOException;
 import java.util.List;
-import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
+import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Waiter.ExplainingPredicate;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.Threads;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.ClassRule;
@@ -125,7 +125,7 @@ public void testTableMergeSwitch() throws Exception {
     assertFalse(admin.getDescriptor(tableName).isMergeEnabled());
 
     trySplitAndEnsureItIsSuccess(tableName);
-    Threads.sleep(10000);
+
     tryMergeAndEnsureItFails(tableName);
     admin.disableTable(tableName);
     enableTableMerge(tableName);
@@ -157,15 +157,17 @@ private void trySplitAndEnsureItFails(final TableName tableName) throws Exceptio
     List<RegionInfo> regions = admin.getRegions(tableName);
     int originalCount = regions.size();
 
-    // split the table and make sure region count does not increase
-    Future<?> f = admin.splitRegionAsync(regions.get(0).getEncodedNameAsBytes(), Bytes.toBytes(2));
     try {
+      // split the table and make sure region count does not increase
+      Future<?> f =
+        admin.splitRegionAsync(regions.get(0).getEncodedNameAsBytes(), Bytes.toBytes(2));
       f.get(10, TimeUnit.SECONDS);
       fail("Should not get here.");
-    } catch (ExecutionException ee) {
+    } catch (IOException ee) {
       // expected to reach here
       // check and ensure that table does not get splitted
       assertTrue(admin.getRegions(tableName).size() == originalCount);
+      assertTrue("Expected DoNotRetryIOException!", ee instanceof DoNotRetryIOException);
     }
   }
 
@@ -216,15 +218,16 @@ private void tryMergeAndEnsureItFails(final TableName tableName) throws Exceptio
     byte[] nameOfRegionA = regions.get(0).getEncodedNameAsBytes();
     byte[] nameOfRegionB = regions.get(1).getEncodedNameAsBytes();
 
-    // check and ensure that region do not get merged
-    Future<?> f = admin.mergeRegionsAsync(nameOfRegionA, nameOfRegionB, true);
     try {
+      // check and ensure that region do not get merged
+      Future<?> f = admin.mergeRegionsAsync(new byte[][] { nameOfRegionA, nameOfRegionB }, true);
       f.get(10, TimeUnit.SECONDS);
       fail("Should not get here.");
-    } catch (ExecutionException ee) {
+    } catch (IOException ee) {
       // expected to reach here
       // check and ensure that region do not get merged
       assertTrue(admin.getRegions(tableName).size() == originalCount);
+      assertTrue("Expected DoNotRetryIOException!", ee instanceof DoNotRetryIOException);
     }
   }
 
@@ -255,7 +258,7 @@ private void tryMergeAndEnsureItIsSuccess(final TableName tableName) throws Exce
     byte[] nameOfRegionB = regions.get(1).getEncodedNameAsBytes();
 
     // merge the table regions and wait until region count decreases
-    admin.mergeRegionsAsync(nameOfRegionA, nameOfRegionB, true);
+    admin.mergeRegionsAsync(new byte[][] { nameOfRegionA, nameOfRegionB }, true);
     TEST_UTIL.waitFor(30000, new ExplainingPredicate<Exception>() {
 
       @Override