The sFlow instrumentation for Memcached includes server side response time measurements.
http://host-sflow.sourceforge.net/relatedlinks.php The response time data isn't particularly interesting when using an in memory cache - it's more interesting if the memcache protocol is being used to access persistent key value stores. The sFlow instrumentation is extremely lightweight and is intended to run continuously in production settings to provide useful operational data (like identifying hot keys etc). It is also designed to be part of a comprehensive monitoring system that includes the web servers, load balancers and network switches. http://blog.sflow.com/search/label/Memcache http://blog.sflow.com/search/label/HTTP Peter On Sat, Jul 13, 2013 at 4:08 AM, Arjen van der Meijden <[email protected]>wrote: > Can't you do something with outside profiling tools? For instance oprofile? > http://oprofile.sourceforge.**net/ <http://oprofile.sourceforge.net/> > > That's a (linux) kernel-level profiler that can gather fairly useful bits > of information without having to run a modified version of memcached and > without having to run it permanently. > > Have a look at the examples, especially the "Symbol summary for a single > application including libraries". It appears to be a sampling profiler, so > it might not give you exactly what you want. > > There is also the 'new' perf-module for linux kernels: > https://perf.wiki.kernel.org/ > > But that seems to gather similar statistics at its most detailed level. > > Other than that, you could look at tools at the network-layer-level. Even > outside the server by using the port mirroring feature from a decent > managed switch. > > Best regards, > > Arjen > > > On 13-7-2013 0:58 Manish Jain wrote: > >> Nice. Is there any methodology I could apply to actually gather server >> side response times, say even at the cost of slightly performance >> degradation? >> >> >> On Fri, Jul 12, 2013 at 3:47 PM, dormando <[email protected] >> <mailto:[email protected]>> wrote: >> >> On a healthy machine, over the network, and memcached isn't >> overloaded, >> 0.1ms response times are what you should expect. >> >> On Fri, 12 Jul 2013, Manish Jain wrote: >> >> > Then, what would be a reasonable estimate of latency of GET and >> SET operations on memcached server? A milli second? >> > -mrjn >> > >> > >> > >> > On Fri, Jul 12, 2013 at 3:32 PM, dormando <[email protected] >> <mailto:[email protected]>> wrote: >> > Those don't really lag... just "stats sizes", so don't call >> that one. Also >> > "stats cachedump" isn't very fast. >> > >> > If there's any latency at all on a standard operation it's >> almost always >> > an outside issue (swap, network, etc), or a massive fault >> of the software. >> > >> > Just adding timing measurements internally slows down the >> entire operation >> > significantly, which is why we don't do it. >> > >> > On Fri, 12 Jul 2013, Manish Jain wrote: >> > >> > > Is there a way to get server side latency stats for >> Memcached operations, like GET, SET, INCREMENT etc? >> > > memcached stats tells you total number of gets and sets, >> but doesn't indicate anything about the latency of those operations. >> > > >> > > Cheers, >> > > Manish >> > > >> > > -- >> > > >> > > --- >> > > 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+unsubscribe@**googlegroups.com<memcached%[email protected]> >> >> <mailto:memcached%**[email protected]<memcached%[email protected]> >> **>. >> >> > > For more options, visit https://groups.google.com/** >> groups/opt_out <https://groups.google.com/groups/opt_out>. >> > > >> > > >> > > >> > > >> > >> > -- >> > >> > --- >> > 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+unsubscribe@**googlegroups.com<memcached%[email protected]> >> >> <mailto:memcached%**[email protected]<memcached%[email protected]> >> **>. >> >> > For more options, visit >> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >> . >> > >> > >> > >> > -- >> > >> > --- >> > 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+unsubscribe@**googlegroups.com<memcached%[email protected]> >> >> <mailto:memcached%**[email protected]<memcached%[email protected]> >> **>. >> >> > For more options, visit >> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >> . >> > >> > >> > >> > >> >> -- >> >> --- >> 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+unsubscribe@**googlegroups.com<memcached%[email protected]> >> >> <mailto:memcached%**[email protected]<memcached%[email protected]> >> **>. >> >> For more options, visit >> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >> . >> >> >> >> -- >> >> --- >> 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+unsubscribe@**googlegroups.com<memcached%[email protected]> >> . >> For more options, visit >> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >> . >> >> >> > -- > > --- 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+unsubscribe@**googlegroups.com<memcached%[email protected]> > . > For more options, visit > https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> > . > > > -- --- You received this message because you are subscribed to the Google Groups "memcached" group. 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