From cfeb26d27a3f5c80e5e8e3d29fd94921251075c4 Mon Sep 17 00:00:00 2001
From: Michael Stack <stack@apache.org>
Date: Thu, 7 Jun 2018 09:50:54 -0700
Subject: [PATCH] HBASE-20702 Processing crash, skip ONLINE'ing empty rows
 Signed-off-by: Josh Elser <elserj@apache.org>

---
 .../hbase/master/assignment/AssignmentManager.java  | 13 +++++++++++--
 .../hbase/master/assignment/RegionStateStore.java   |  4 ++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
index 35e4aa4f1bf..3c9b0d3d030 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
@@ -48,6 +48,7 @@ import org.apache.hadoop.hbase.YouAreDeadException;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.RegionReplicaUtil;
+import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.TableState;
 import org.apache.hadoop.hbase.exceptions.UnexpectedStateException;
 import org.apache.hadoop.hbase.favored.FavoredNodesManager;
@@ -77,6 +78,7 @@ import org.apache.hadoop.hbase.procedure2.ProcedureEvent;
 import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
 import org.apache.hadoop.hbase.procedure2.ProcedureInMemoryChore;
 import org.apache.hadoop.hbase.procedure2.util.StringUtils;
+import org.apache.hadoop.hbase.regionserver.SequenceId;
 import org.apache.hadoop.hbase.util.HasThread;
 import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
@@ -1235,9 +1237,14 @@ public class AssignmentManager implements ServerListener {
     // TODO: use a thread pool
     regionStateStore.visitMeta(new RegionStateStore.RegionStateVisitor() {
       @Override
-      public void visitRegionState(final RegionInfo regionInfo, final State state,
+      public void visitRegionState(Result result, final RegionInfo regionInfo, final State state,
           final ServerName regionLocation, final ServerName lastHost, final long openSeqNum) {
-        final RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(regionInfo);
+        if (state == null && regionLocation == null && lastHost == null &&
+            openSeqNum == SequenceId.NO_SEQUENCE_ID) {
+          // This is a row with nothing in it.
+          LOG.warn("Skipping empty row={}", result);
+          return;
+        }
         State localState = state;
         if (localState == null) {
           // No region state column data in hbase:meta table! Are I doing a rolling upgrade from
@@ -1245,8 +1252,10 @@ public class AssignmentManager implements ServerListener {
           // In any of these cases, state is empty. For now, presume OFFLINE but there are probably
           // cases where we need to probe more to be sure this correct; TODO informed by experience.
           LOG.info(regionInfo.getEncodedName() + " regionState=null; presuming " + State.OFFLINE);
+
           localState = State.OFFLINE;
         }
+        final RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(regionInfo);
         synchronized (regionNode) {
           if (!regionNode.isInTransition()) {
             regionNode.setState(localState);
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java
index 81f0f0a2660..fa252316d62 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateStore.java
@@ -68,7 +68,7 @@ public class RegionStateStore {
   }
 
   public interface RegionStateVisitor {
-    void visitRegionState(RegionInfo regionInfo, State state,
+    void visitRegionState(Result result, RegionInfo regionInfo, State state,
       ServerName regionLocation, ServerName lastHost, long openSeqNum);
   }
 
@@ -121,7 +121,7 @@ public class RegionStateStore {
       // TODO: move under trace, now is visible for debugging
       LOG.info("Load hbase:meta entry region={}, regionState={}, lastHost={}, " +
           "regionLocation={}", regionInfo.getEncodedName(), state, lastHost, regionLocation);
-      visitor.visitRegionState(regionInfo, state, regionLocation, lastHost, openSeqNum);
+      visitor.visitRegionState(result, regionInfo, state, regionLocation, lastHost, openSeqNum);
     }
   }