HBASE-20111 A region's splittable state now includes the configuration splitPolicy

The Master asks a RegionServer whether a Region can be split or not, primarily to
verify that the region is not closing, opening, etc. This change has the RegionServer
also consult the configured RegionSplitPolicy.

Signed-off-by: Josh Elser <elserj@apache.org>

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

@@ -179,7 +179,7 @@ public class SplitTableRegionProcedure
     }
 
     if (!splittable) {
-      IOException e = new IOException(regionToSplit.getShortNameToLog() + " NOT splittable");
+      IOException e = new DoNotRetryIOException(regionToSplit.getShortNameToLog() + " NOT splittable");
       if (splittableCheckIOE != null) e.initCause(splittableCheckIOE);
       throw e;
     }

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

@@ -1736,10 +1736,13 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
       HRegion region = getRegion(request.getRegion());
       RegionInfo info = region.getRegionInfo();
       byte[] bestSplitRow = null;
+      boolean shouldSplit = true;
       if (request.hasBestSplitRow() && request.getBestSplitRow()) {
         HRegion r = region;
         region.startRegionOperation(Operation.SPLIT_REGION);
         r.forceSplit(null);
+        // Even after setting force split if split policy says no to split then we should not split.
+        shouldSplit = region.getSplitPolicy().shouldSplit() && !info.isMetaRegion();
         bestSplitRow = r.checkSplit();
         // when all table data are in memstore, bestSplitRow = null
         // try to flush region first
@@ -1754,7 +1757,7 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
       if (request.hasCompactionState() && request.getCompactionState()) {
         builder.setCompactionState(ProtobufUtil.createCompactionState(region.getCompactionState()));
       }
-      builder.setSplittable(region.isSplittable());
+      builder.setSplittable(region.isSplittable() && shouldSplit);
       builder.setMergeable(region.isMergeable());
       if (request.hasBestSplitRow() && request.getBestSplitRow() && bestSplitRow != null) {
         builder.setBestSplitRow(UnsafeByteOperations.unsafeWrap(bestSplitRow));

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAdmin1.java

@@ -31,6 +31,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
+
 import org.apache.hadoop.hbase.HBaseClassTestRule;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HColumnDescriptor;
@@ -46,6 +47,7 @@ import org.apache.hadoop.hbase.TableNotEnabledException;
 import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.exceptions.MergeRegionException;
 import org.apache.hadoop.hbase.master.LoadBalancer;
+import org.apache.hadoop.hbase.regionserver.DisabledRegionSplitPolicy;
 import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.regionserver.HStore;
 import org.apache.hadoop.hbase.regionserver.HStoreFile;
@@ -54,6 +56,7 @@ import org.apache.hadoop.hbase.testclassification.LargeTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.hadoop.hbase.util.Threads;
 import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Before;
@@ -65,7 +68,6 @@ import org.junit.experimental.categories.Category;
 import org.junit.rules.TestName;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
 import org.apache.hadoop.hbase.shaded.protobuf.RequestConverter;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.MergeTableRegionsRequest;
 
@@ -1391,4 +1393,32 @@ public class TestAdmin1 {
       this.admin.deleteTable(tableName);
     }
   }
+
+  @Test
+  public void testSplitShouldNotHappenIfSplitIsDisabledForTable()
+      throws Exception {
+    final TableName tableName = TableName.valueOf(name.getMethodName());
+    HTableDescriptor htd = new HTableDescriptor(tableName);
+    htd.addFamily(new HColumnDescriptor("f"));
+    htd.setRegionSplitPolicyClassName(DisabledRegionSplitPolicy.class.getName());
+    Table table = TEST_UTIL.createTable(htd, null);
+    for(int i = 0; i < 10; i++) {
+      Put p = new Put(Bytes.toBytes("row"+i));
+      byte[] q1 = Bytes.toBytes("q1");
+      byte[] v1 = Bytes.toBytes("v1");
+      p.addColumn(Bytes.toBytes("f"), q1, v1);
+      table.put(p);
+    }
+    this.admin.flush(tableName);
+    try {
+      this.admin.split(tableName, Bytes.toBytes("row5"));
+      Threads.sleep(10000);
+    } catch (Exception e) {
+      // Nothing to do.
+    }
+    // Split should not happen.
+    List<RegionInfo> allRegions = MetaTableAccessor.getTableRegions(
+        this.admin.getConnection(), tableName, true);
+    assertEquals(1, allRegions.size());
+  }
 }