HBASE-23294 ReplicationBarrierCleaner should delete all the barriers for a removed region which does not belong to any serial replication peer (#827)

Signed-off-by: stack <stack@apache.org>

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

@@ -99,13 +99,22 @@ public class ReplicationBarrierCleaner extends ScheduledChore {
           peerIds = peerManager.getSerialPeerIdsBelongsTo(tableName);
         }
         if (peerIds.isEmpty()) {
-          // no serial replication, only keep the newest barrier
+          // no serial replication
+          // check if the region has already been removed, i.e, no catalog family
+          if (metaTable.exists(new Get(regionName).addFamily(HConstants.CATALOG_FAMILY))) {
+            // exists, then only keep the newest barrier
             Cell cell = result.getColumnLatestCell(HConstants.REPLICATION_BARRIER_FAMILY,
               HConstants.SEQNUM_QUALIFIER);
             metaTable.delete(new Delete(regionName).addFamily(HConstants.REPLICATION_BARRIER_FAMILY,
               cell.getTimestamp() - 1));
-          cleanedRows++;
             deletedBarriers += barriers.length - 1;
+          } else {
+            // not exists, delete all the barriers
+            metaTable
+              .delete(new Delete(regionName).addFamily(HConstants.REPLICATION_BARRIER_FAMILY));
+            deletedBarriers += barriers.length;
+          }
+          cleanedRows++;
           continue;
         }
         String encodedRegionName = RegionInfo.encodeRegionName(regionName);

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

@@ -181,17 +181,21 @@ public class TestReplicationBarrierCleaner {
     RegionInfo region11 =
       RegionInfoBuilder.newBuilder(tableName1).setEndKey(Bytes.toBytes(1)).build();
     addBarrier(region11, 10, 20, 30, 40, 50, 60);
+    fillCatalogFamily(region11);
     RegionInfo region12 =
       RegionInfoBuilder.newBuilder(tableName1).setStartKey(Bytes.toBytes(1)).build();
     addBarrier(region12, 20, 30, 40, 50, 60, 70);
+    fillCatalogFamily(region12);
 
     TableName tableName2 = TableName.valueOf(name.getMethodName() + "_2");
     RegionInfo region21 =
       RegionInfoBuilder.newBuilder(tableName2).setEndKey(Bytes.toBytes(1)).build();
     addBarrier(region21, 100, 200, 300, 400);
+    fillCatalogFamily(region21);
     RegionInfo region22 =
       RegionInfoBuilder.newBuilder(tableName2).setStartKey(Bytes.toBytes(1)).build();
     addBarrier(region22, 200, 300, 400, 500, 600);
+    fillCatalogFamily(region22);
 
     @SuppressWarnings("unchecked")
     ReplicationPeerManager peerManager =
@@ -285,6 +289,25 @@ public class TestReplicationBarrierCleaner {
       Arrays.asList(region.getEncodedName()));
   }
 
+  @Test
+  public void testDeleteRowForDeletedRegionNoPeers() throws IOException {
+    TableName tableName = TableName.valueOf(name.getMethodName());
+    RegionInfo region = RegionInfoBuilder.newBuilder(tableName).build();
+    addBarrier(region, 40, 50, 60);
+
+    ReplicationPeerManager peerManager = mock(ReplicationPeerManager.class);
+    ReplicationBarrierCleaner cleaner = create(peerManager);
+    cleaner.chore();
+
+    verify(peerManager, times(1)).getSerialPeerIdsBelongsTo(tableName);
+    // There are no peers, and no catalog family for this region either, so we should remove the
+    // barriers. And since there is no catalog family, after we delete the barrier family, the whole
+    // row is deleted.
+    try (Table table = UTIL.getConnection().getTable(TableName.META_TABLE_NAME)) {
+      assertFalse(table.exists(new Get(region.getRegionName())));
+    }
+  }
+
   private static class WarnOnlyStoppable implements Stoppable {
     @Override
     public void stop(String why) {