Forgot to say I'm running version 1.4.13 libevent 2.0.16-stable
On Thu, Aug 7, 2014 at 6:08 PM, Claudio Santana <claudio.sant...@gmail.com> wrote: > Sorry for the late response. > > My CPU utilization normally is min 2.5% to 6.5% max. > > So it's interesting you ask this. The reason why I submitted the 1st > question is because I've experienced some random CPU utilization spikes. > From this about 6% CPU utilization all of the sudden it spikes to 100% and > I can see the offending process is one of the Memcached instances. Sadly > this CPU spike is accompanied by all requests timing out causing the whole > system to become unusable. > > I collect minute by minute stats of all these memcached instances and > according to my stats this issue happens within 2 minutes. I can see in the > number of commands there's no increase in number of commands being issued > right before the CPU spike nor increase in the number of bytes in/out. > > Does anybody have any ideas of what could be going on? > > I have all Memcached stats collected by minute in Graphite, I can provide > other stats that could help explain this issue if necessary. > > > On Mon, Aug 4, 2014 at 9:36 PM, dormando <dorma...@rydia.net> wrote: > >> You could run one instance with one thread and serve all of that just >> fine. have you actually looked at graphs of the CPU usage of the host? >> memcached should be practically idle with load that low. >> >> One with -t 6 or -t 8 would do it just fine. >> >> On Mon, 4 Aug 2014, Claudio Santana wrote: >> >> > Dormando, thanks for the quick response. Sorry for the confusion, I >> don't have exact metrics per second but per minute 1.12 >> > million sets and 1.8 million gets which translates to 18,666 sets per >> minute and 30,000 gets per second. >> > >> > These stats are per Memcached instance which I currently run 3 on each >> server. >> > >> > Claudio. >> > >> > >> > On Mon, Aug 4, 2014 at 6:22 PM, dormando <dorma...@rydia.net> wrote: >> > On Mon, 4 Aug 2014, Claudio Santana wrote: >> > >> > > I have this Memcached cluster where 3 instances of Memcached >> run in a single server. These servers have 24 cores, >> > each instance >> > > is configured to have 8 threads each. Each individual instance >> serves have about 5000G gets/sets a day and about >> > 3k current >> > > connections. >> > >> > I don't know what "5000G gets/sets a day" translates to in per-second >> (nor >> > what the G-unit even is?), can you define this? >> > >> > > What would be better? consolidate these 3 instances to a single >> instance per server with 24 threads? I've read in a few >> > articles >> > > that Memcached's performance starts suffering with more than 4-6 >> threads per instance, is this generally true? >> > > >> > > How about keeping the 3 instances per server and decreasing the >> number of threads to say 4 or 6? or creating 4 instances >> > in the >> > > same servers instead of 3 and decreasing the number of threads per >> instance to 6 so there is one thread per core. >> > > >> > > Is there a guide you could recommend to configure the right number of >> threads and strategies to get the most out of a >> > Memcached >> > > server/instance? >> > > >> > > Thanks, >> > > Claudio >> > > >> > > -- >> > > >> > > --- >> > > You received this message because you are subscribed to the Google >> Groups "memcached" group. >> > > To unsubscribe from this group and stop receiving emails from it, >> send an email to >> > memcached+unsubscr...@googlegroups.com. >> > > For more options, visit https://groups.google.com/d/optout. >> > > >> > > >> > >> > -- >> > >> > --- >> > You received this message because you are subscribed to the Google >> Groups "memcached" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to memcached+unsubscr...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. >> > >> > >> > -- >> > >> > --- >> > You received this message because you are subscribed to the Google >> Groups "memcached" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to memcached+unsubscr...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. >> > >> > >> >> -- >> >> --- >> You received this message because you are subscribed to the Google Groups >> "memcached" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to memcached+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > -- --- You received this message because you are subscribed to the Google Groups "memcached" group. To unsubscribe from this group and stop receiving emails from it, send an email to memcached+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
