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 <divya.mohan...@gmail.com>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 <p...@imatix.com> wrote: > >> On Wed, Mar 27, 2013 at 4:51 PM, Divya Mohan <divya.mohan...@gmail.com> >> 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 >> zeromq-dev@lists.zeromq.org >> http://lists.zeromq.org/mailman/listinfo/zeromq-dev >> > > > _______________________________________________ > zeromq-dev mailing list > zeromq-dev@lists.zeromq.org > http://lists.zeromq.org/mailman/listinfo/zeromq-dev > >
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