@Override
    public String toString() {
      if (compaction != null) {
        return "Request=" + compaction.getRequest();
      } else {
        return "region=" + region.toString() + ", storeName=" + store.toString() + ", priority="
          + queuedPriority + ", startTime=" + time;
      }
    }
Check if this store is under compaction
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/CompactSplit.java