Stats when recent spike happens for 15 minutes around it get (826) save (341) listByIndex (1161) mapReduce (621) //Input is IDs list SOLR (4294)
6 Solr requests was longer than 9sec ( all returns 0 rows ) 4 Solr requests was longer within 4-5s ( both returns 0 rows ) 11 listByIndex requests was longer than within 4-5s ( both returns 0 rows ) all another requests was less than 300ms Sometimes more load do not make such spikes Some graphs from maintanance tasks: 1. http://i.imgur.com/xAE6B06.png 3 simple tasks, first 2 of them reads all keys, decide to do nothing and continue so just read happens, third task resave all data in bucket. since rate is pretty good, some peaks happens 2. More complex task http://i.imgur.com/7nwHb3Q.png, it have more serious computing, and updating typed bucked( map ), but no peaks to 9s sysctl -a | fgrep vm.dirty_: vm.dirty_background_bytes = 0 vm.dirty_background_ratio = 10 vm.dirty_bytes = 0 vm.dirty_expire_centisecs = 3000 vm.dirty_ratio = 20 vm.dirty_writeback_centisecs = 500 On Tue, Dec 9, 2014 at 5:46 PM, Luke Bakken <lbak...@basho.com> wrote: > Hi Alexander, > > Can you comment on the read vs. write load of this cluster/ > > Could you please run the following command and reply with the output? > > sysctl -a | fgrep vm.dirty_ > > We've seen cases where dirty pages get written in a synchronous manner > all at once, causing latency spikes due to I/O blocking. > -- > Luke Bakken > Engineer / CSE > lbak...@basho.com > > > On Tue, Dec 9, 2014 at 4:58 AM, Alexander Popov <mogada...@gmail.com> wrote: >> I have Riak 2.0.1 cluster with 5 nodes ( ec2 m3-large ) with elnm in front >> sometimes I got spikes up to 10 seconds >> >> I can't say that I have huge load at this time, max 200 requests per >> second for all 5 nodes. >> >> Most expensive queries is >> * list by secondary index ( usually returns from 0 to 100 records ) >> * and solr queries( max 10 records ) >> >> save operations is slowdown sometimes but not so much ( up to 1 sec ) >> >> It's slowdown not for specific requests, same one work pretty fast later. >> >> Does it any possibilities to profile|log somehow to determine reason >> why this happen? >> >> _______________________________________________ >> riak-users mailing list >> riak-users@lists.basho.com >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
