Yes, the majority of the cost is probably in TCP setup. That pain is happening at the TCP stack level, not in Erlang. It's actually really cheap and easy to spawn a new process in Erlang, so there's no reason to have "standby workers", especially when they don't need to maintain state between requests.
Sean Cribbs <s...@basho.com> Developer Advocate Basho Technologies, Inc. http://basho.com/ On Feb 25, 2011, at 12:45 PM, Wilson MacGyver wrote: > I've tried it, it didn't have much impact. A bit more info on how I'm > doing the test. > > I'm using apachebench. I purposely have it grab the same key/value over and > over > again. > > if I use concurrent connection of 10, 1000 requests each. 50% of the > request complets > within 7ms, longest request is 38ms. this is quite good. > > now, if I increase the concurrent connection to 100, 50% of the > request complets at 77ms. > > it "feels" like a paying for startup cost of connection problem to me. > Is there a way to purposely > startup riak with a bunch of standby workers, or something to that effect? > > On Fri, Feb 25, 2011 at 11:37 AM, Sean Cribbs <s...@basho.com> wrote: >> You can disable Nagle on the riak side (at least on 0.14 and later). Put >> this in the riak_core section of app.config: >> >> {disable_http_nagle, true} >> >> Sean Cribbs <s...@basho.com> >> Developer Advocate >> Basho Technologies, Inc. >> http://basho.com/ >> >> On Feb 25, 2011, at 9:33 AM, Wilson MacGyver wrote: >> >>> TCP_NODELAY is something you'd set when you use the socket API call, >>> not a global tuning setting on the OS as I recall. >>> >>> On Fri, Feb 25, 2011 at 9:28 AM, Nico Meyer <nico.me...@adition.com> wrote: >>>> Whenever I see latencies which are roughly multiples of 40ms it screams >>>> to me 'nagle algorithm'. I have seen this so often now, that the first >>>> thing I check is, if the TCP_NODELAY option is set on the TCP socket on >>>> both ends. >>> > > -- > Omnem crede diem tibi diluxisse supremum. > > _______________________________________________ > 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
