Affects Version/s: None
|clearRegionBlockCache||Severe||The API will call LruBlockCache.evictBlocksByHfileName,
who is declared as an expensive operation(see its comments), thus non-amin may result Dos
|clearSlowLogsResponses||Normal||clears queue records from ringbuffer|
|updateConfiguration||Normal||non-admin user can make RS reload configutation from disk by this API.|
|updateRegionFavoredNodesMapping||Normal||Non-admin user can change the region's best storage location by this api|
|stopServer||low||stopServer on RS is slient, which make client think he/she success shutdown RS.
Add preRpcCheck ont only make client receive the failed message,
but also prevent the non-admin user stop the RS,
even the hbase.coprocessor.regionserver.classes are not configured.