Memcached slow queries | 易学教程

问题

I am actually expecting slow response times for certain requests on memcached. I am running a nodeJS server, the client is node-memcached. From the log files, I extracted the response times distribution which looks like this:

Count   Response time (ms)

6204    00001
4627    00002
1465    00003
 414    00004
 141    00005
  69    00006
  23    00007
  17    00008
  11    00009
   2    00010
   2    00011
   2    00012
   1    00015
   1    00016
   1    00020
   1    00023
   1    00024
   1    00026
   1    00076
   1    00212
   1    00213
   1    00214
   1    00215
   1    00217
   1    00219
   1    00220
   1    03004
   1    03010

What's really strange is those outlier requests, which consume around 215 and 3000 ms. The object stored are basically the same, memcached version is 1.4.5. Here's the statistics from one of the (8) servers:

STAT pid 2359
STAT uptime 12131402
STAT time 1355303458
STAT version 1.4.5
STAT pointer_size 64
STAT rusage_user 161954.749539
STAT rusage_system 423668.017596
STAT curr_connections 930
STAT total_connections 12097997
STAT connection_structures 1254
STAT cmd_get 46838365743
STAT cmd_set 1560759291
STAT cmd_flush 0
STAT get_hits 40796019120
STAT get_misses 6042346623
STAT delete_misses 237357218
STAT delete_hits 49942676
STAT incr_misses 0
STAT incr_hits 0
STAT decr_misses 0
STAT decr_hits 0
STAT cas_misses 0
STAT cas_hits 0
STAT cas_badval 0
STAT auth_cmds 0
STAT auth_errors 0
STAT bytes_read 4178933811835
STAT bytes_written 64248216431317
STAT limit_maxbytes 24062722048
STAT accepting_conns 1
STAT listen_disabled_num 0
STAT threads 8
STAT conn_yields 3956
STAT bytes 21362090264
STAT curr_items 14583102
STAT total_items 1560759290
STAT evictions 712640376
STAT reclaimed 131709403

来源：https://stackoverflow.com/questions/13841493/memcached-slow-queries

标签

performance

memcached