Hi Asif, I'm hoping Divya will provide us with reusable tests that show the problem.
-Pieter On Mon, Apr 15, 2013 at 7:50 AM, asif saeed <[email protected]> wrote: > Excellent, Divya. Very good analysis. > > @Pieter, > > I am also going to use ZeroMQ in an Ubuntu environment and Divya's analysis > is really worrying me. Does ZeroMQ have benchmarks on non real-time systems? > What kind of performance tests are there to test the performance? > > Sincerely, > > -Asif > > > On Fri, Apr 12, 2013 at 10:29 PM, Divya Mohan <[email protected]> > wrote: >> >> Hi Pieter, >> >> I tried the same performance tests with POSIX message queues and there was >> no delay in receiving the messages. The same test with ZeroMQ showed delays >> of upto 470msec. Doesn't this mean that we can rule out the possibility of >> another process taking up CPU time randomly (as you had suggested earlier)? >> >> Are there any sleep/wait (for semaphores) in the zeromq code that could >> send my process to suspeneded/sleep state. I am not able to figure out why >> this delay is seen when using ZeroMq and not with message queues. >> >> >> >> Thanks, >> >> Divya >> >> >> >> >> >> On Thu, Mar 28, 2013 at 3:54 PM, Pieter Hintjens <[email protected]> wrote: >>> >>> On Wed, Mar 27, 2013 at 4:51 PM, Divya Mohan <[email protected]> >>> wrote: >>> >>> > Current and default scheduling policy is SCHED_OTHER. I had given >>> > highest >>> > priority to my receive process thinking delay due to scheduling will be >>> > taken care off but even then the messages are delayed. >>> > >>> > Also I am not using any sleep in my receive process. Only send process >>> > has >>> > a sleep of 1 msec. >>> >>> In general changing thread priorities is a bad idea. >>> >>> Perhaps you have another process taking CPU time at random occasions, >>> causing the sender I/O thread to be swapped out. >>> >>> If you want guarantees that there are no spikes you'll have to use a >>> real time kernel. It will increase average latency but remove the >>> spikes. >>> >>> -Pieter >>> _______________________________________________ >>> zeromq-dev mailing list >>> [email protected] >>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev >> >> >> >> _______________________________________________ >> zeromq-dev mailing list >> [email protected] >> http://lists.zeromq.org/mailman/listinfo/zeromq-dev >> > > > _______________________________________________ > zeromq-dev mailing list > [email protected] > http://lists.zeromq.org/mailman/listinfo/zeromq-dev > _______________________________________________ zeromq-dev mailing list [email protected] http://lists.zeromq.org/mailman/listinfo/zeromq-dev
