From 238c9b40bf73f6038d60ebf7c99444b7fee373ab Mon Sep 17 00:00:00 2001
From: Xiaolin Ha <haxiaolin@apache.org>
Date: Thu, 12 Aug 2021 17:09:18 +0800
Subject: [PATCH] HBASE-26155 JVM crash when scan (#3553)

Signed-off-by: Michael Stack <stack@apache.org>
Signed-off-by: Duo Zhang <zhangduo@apache.org>
---
 .../org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java | 5 +++++
 .../org/apache/hadoop/hbase/regionserver/StoreScanner.java   | 3 +--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
index 0187f5eb435..9dc40d02ccf 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/bucket/BucketCache.java
@@ -430,6 +430,11 @@ public class BucketCache implements BlockCache, HeapSize {
     if (cacheEnabled) {
       if (backingMap.containsKey(cacheKey) || ramCache.containsKey(cacheKey)) {
         if (BlockCacheUtil.shouldReplaceExistingCacheBlock(this, cacheKey, cachedItem)) {
+          BucketEntry bucketEntry = backingMap.get(cacheKey);
+          if (bucketEntry != null && bucketEntry.isRpcRef()) {
+            // avoid replace when there are RPC refs for the bucket entry in bucket cache
+            return;
+          }
           cacheBlockWithWaitInternal(cacheKey, cachedItem, inMemory, wait);
         }
       } else {
diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java
index 5ad29bb488c..9505fb07e0d 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java
@@ -29,10 +29,9 @@ import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.DoNotRetryIOException;
-import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.PrivateConstants;
 import org.apache.hadoop.hbase.client.IsolationLevel;
 import org.apache.hadoop.hbase.client.Scan;