Hi, First as an aside; 1/1 get/set ratio is unusual for mc. The gets scale a lot better than sets. If you get into testing more "realistic" perf numbers make sure to increase the get rate.
You're probably just running into CPU scaling. OS's come with a "battery saver" or "ondemand" performance scheduler by default. They also have turbo. Once you start loading it up more the CPU will stay in the higher frequency states or begin to issue turbo, which will lower the latency. /usr/bin/echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo cpupower frequency-set -g performance ... or whatever works for your platform. On Mon, 7 Oct 2019, Pradeep Fernando wrote: > Hi Devs, > I run memaslap to understand the performance characteristics of memcached, > > My setup : both memcached and memaslap running on a single machine with NUMA. > memcached is bound to NUMA 1. Gave 3GB of memory to memcached. > workload : get/set 0.5/0.5 > > I increase number of thread from memaslap and observe throughput latency > numbers. > > I see increase in throughput (expected) but latency drops as I crease the > load. > The initial average latency is 83 us and it drops to 30us with number of > threads = 8, this is an unexpected number.-- I expected the latency to go up. > Am I reading the output wrong? > > Apologies, if this question does not qualify for this mailing list. If so, > please direct me to correct list I can get help. :) > > --Pradeep > > > > Thread count = 1 > > > Total Statistics (11447336 events) > Min: 11 > Max: 1663 > Avg: 83 > Geo: 79.83 > Std: 36.39 > Log2 Dist: > 4: 42 594 351733 9527982 > 8: 1551101 7451 7103 1330 > > cmd_get: 5723671 > cmd_set: 5723681 > get_misses: 0 > written_bytes: 394933167 > read_bytes: 343419948 > object_bytes: 183157792 > > Run time: 60.0s Ops: 11447352 TPS: 190765 Net_rate: 11.7M/s > > Thread count = 2 > > Total Statistics (30888799 events) > Min: 12 > Max: 2011 > Avg: 30 > Geo: 29.68 > Std: 15.32 > Log2 Dist: > 4: 170225 25862674 4766668 66398 > 8: 154 5017 17493 170 > > cmd_get: 15444404 > cmd_set: 15444411 > get_misses: 0 > written_bytes: 1065663678 > read_bytes: 926663772 > object_bytes: 494221152 > > Run time: 60.0s Ops: 30888815 TPS: 514751 Net_rate: 31.7M/s > > -- > > --- > 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/cd593815-c27b-4995-bb7f-21859d9a3187%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/alpine.DEB.2.21.1910071005340.21578%40dskull.
