After continuous monitoring the regionserver log, we found region forced to flush are all relevant to Phoenix tables. so it leads us  to the Phoenix issue PHOENIX-5250. As our Phoenix relevant business are okay for occasional data loss, so we turn off phoenix table's WAL  through alter table xxx set DISABLE_WAL = true and then restart those regionservers who have problems flushing problematic edits(if they are too many WALs, try just keep recent ones or HMaster will try to replay lots of WAL), currently WAL logs are archived as expected. Of course, if DISABLE_WAL = true is not your option, then you should try to upgrade Phoenix. Best regards. ... View more