Hey, Definitely not enough information from what you provide here. Typically "CPU usage goes up" isn't correlated to "memcached is slow". You usually see CPU usage go down, because the servers are waiting on data over the network and are thus idle.
This can change in a few ways, ie; if your PHP servers have low timeouts and are spin-looping/etc. Or some change in traffic is making lots of calls to memcached, which translates to lots of syscalls, which translates to CPU usage on the PHP servers. Sorry, unfortunately this is too general of an issue. It's common to wonder if an issue is memcached or not, and we have this wiki page to help troubleshoot that: https://github.com/memcached/memcached/wiki/Timeouts - don't skip steps! use the conn tester, read it carefully, etc. On Mon, 11 Apr 2022, Scaler wrote: > Hello, > In production environment I have seen CPU usage go up in PHP servers, with > PHP profiler showing possibly memcached(or DB or something else) as culprit. > Profiler shows definite memcached being slow but also other things too, so > not definite. > > memcached server hardware(and hardware connecting to it) is > Intel Corporation Ethernet Controller 10-Gigabit X540-AT2 (rev 01) > with 10GBASE-T, short less than 5 m cat 7 cable hooked up to Cisco Nexus > switch as layer 2 network. > > I noticed at about 400,000 memcached requests per second and at about 3~5 > Gbps traffic the above problems occur(many small requests per second). > Benchmarking the LAN card with simply iperf iperf3 I can easily get 9.x Gbps > flow. > > Do you think the LAN card could be the limiting factor is such case(many > small packets)? > Or should such LAN cards be sufficient for such traffic and I should look > elsewhere for the performance issues. > > Thank you. > > -- > > --- > 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. > To view this discussion on the web visit > https://groups.google.com/d/msgid/memcached/c2c68e33-3683-46e3-8f42-5b7f0040c768n%40googlegroups.com. > > -- --- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/memcached/a919ef1d-8f75-6b3e-204e-85fb6aff7f2%40rydia.net.
