Now you're talking about tweaking kernel-level settings -- something well outside my expertise (although TCP slow-start comes to mind). That said, it's kind of hard not to use TCP if you want a reliable connection, warts and all.
Sean Cribbs <s...@basho.com> Developer Advocate Basho Technologies, Inc. http://basho.com/ On Feb 25, 2011, at 1:06 PM, Wilson MacGyver wrote: > any advise to solve this? > > On Fri, Feb 25, 2011 at 1:05 PM, Sean Cribbs <s...@basho.com> wrote: >> 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 >> >> > > > > -- > 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
