On Tue, Sep 22, 2015 at 12:16 PM, Shrijeet <shrij...@pinterest.com.invalid> wrote:
> Thanks Stack. Few comments. > > > > Have you put much work into it? If you went to HBASE-10156, write > > throughput is better again and you'd be on same system as is in current > > hbase-1.x so would be easier to help you. > > > > Good to know, 1.x move is planned soonish so will wait for it. > > <snip> > > > > Since AsyncWriter got aborted due to an unhanded exception the > > AsyncSyncer > > > etc. will not be notified, thus deadlocking the server. I am not > familiar > > > with HLog's life cycle, how does it handles errors in its worker > threads? > > > > > > My guess is that they are not supposed to have exited... the exception is > > unexpected. They are not supposed to die in normal operation. > > > > Thats true - in case of a checked exception (IOE in this case) - HLog's > async mechanism marks an append as failed - goes ahead with sync, moves on > & never dies. And I think what you are saying is it might be okay to do > same for this specific (AIOBException raised by HDFS) error too. Fixing > HDFS in not an option right now - so I might have to put a band aid in > HLog. Let me know if I misunderstood. > AIOBE out of HDFS is not expected (smile). Yeah, catch and carry on. Catching all Throwables might make for new headache types. > > <snip> > > In the later versions of the WAL subsystem, there is > > careful handling to make sure we don't do things like fail an append but > > successfully sync. > > > > By later version you mean 1.x and beyond? > Yeah and beyond. See HBASE-14317 St.Ack > > Thanks again! > > > > St.Ack > > > > > > > > > > > > > > // 4. update 'lastWrittenTxid' and notify AsyncSyncer to do 'sync' > > > asyncSyncer.setWrittenTxid(this.lastWrittenTxid); > > > > > >
