Is there any sort of statistic or log of when this compaction occurs? -Anthony
On Wed, Feb 09, 2011 at 12:22:53PM -0500, Alexander Sicular wrote: > not quite sure about the overall problem, but bitcask does do compaction if > your "casks" reach a certain threshold of dead bytes. this is all > configurable and would only be triggered if your updates or deletes pushed > your dead bytes over that threshold. > > -alexander > > On Feb 9, 2011, at 12:12 PM, Anthony Molinaro wrote: > > > Hi, > > > > Any thoughts on this? I added a timeout to my client so its not impacted > > (other than missing some data, but that's okay). However, I still see large > > spikes in the node_(get|put)_fsm_time_100 stats (normal operation seems to > > be > > about 1200, and I see spikes up to 200000). > > > > One thing I thought of is upping the number of async threads. I did > > increase the number of partitions to 1024 and with only 4 nodes in the > > ring I could be hitting some sort of locking at the bitcask layer. > > > > Are there any maintenance tasks that happen with bitcask that could > > cause lag? For instance in our frequency server which uses riak_core > > with a linked in driver for a backend, we have to grow the file every > > so often which lead to these sort of spikes, so maybe bitcask has some > > thing similar? > > > > Thanks, > > > > -Anthony > > > > On Tue, Feb 08, 2011 at 12:09:34PM -0800, Anthony Molinaro wrote: > >> Hi, > >> > >> I have a 4 node cluster using riak_kv_multi_backend with one backend > >> configured to use riak_kv_bitcask_backend. I'm using the multi backend > >> because eventually I want to also run a cache backend. I'm sampling > >> the statistics once per minute and viewing them in rrd and noticed > >> something odd. The node_(get|put)_fsm_time_100 sometimes spike to > >> 60 seconds while 99.99% of the time it's less than 2 milliseconds. > >> > >> I'm going to work around by lowering the timeouts in riak-erlang-client > >> but this seems like it could continue to be a problem if the get/put > >> fsms continue to run even if the client times out. > >> > >> Anyway, just curious if others have experienced this sort of long tail > >> spikiness. > >> > >> -Anthony > >> > >> -- > >> ------------------------------------------------------------------------ > >> Anthony Molinaro <antho...@alumni.caltech.edu> > >> > >> _______________________________________________ > >> riak-users mailing list > >> riak-users@lists.basho.com > >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > > > > -- > > ------------------------------------------------------------------------ > > Anthony Molinaro <antho...@alumni.caltech.edu> > > > > _______________________________________________ > > riak-users mailing list > > riak-users@lists.basho.com > > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > -- ------------------------------------------------------------------------ Anthony Molinaro <antho...@alumni.caltech.edu> _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
