Minor Description
Currently in RegionGroupingProvider#getWAL(String) we're trying to get a WAL instance from the cache using walCacheLock as the key (a typo when fixing HBASE-14306, my fault...), while actually we should have used group name. This won't cause any fatal error but will slightly affect the perf since it will always run into the succeeding synchronized code. Will get this fixed in this JIRA