Index: src/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java =================================================================== --- src/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java (revision 934685) +++ src/java/org/apache/hadoop/hbase/regionserver/StoreScanner.java (working copy) @@ -132,7 +132,8 @@ } public synchronized void close() { - this.closing.set(true); + boolean state = this.closing.getAndSet(true); + if (state) return; // under test, we dont have a this.store if (this.store != null) this.store.deleteChangedReaderObserver(this);