Are these memcached stats normal?

Question

Are these stats normal? I have problems with my PHP products, so I want to know if these data are healthy

stats
STAT pid 2312
STAT uptime 5292037
STAT time 1253692925
STAT version 1.2.8
STAT pointer_size 64
STAT rusage_user 2600.605647
STAT rusage_system 9533.168738
STAT curr_items 1153303
STAT total_items 139795434
STAT bytes 435570863
STAT curr_connections 288
STAT total_connections 135128959
STAT connection_structures 1018
STAT cmd_flush 1
STAT cmd_get 171491050
STAT cmd_set 139795434
STAT get_hits 127840250
STAT get_misses 43650800
STAT evictions 24166536
STAT bytes_read 2731502572454
STAT bytes_written 2889855000126
STAT limit_maxbytes 536870912
STAT threads 2
STAT accepting_conns 1
STAT listen_disabled_num 802
END

Answer 1

Yes, why? Is anything wrong?

STAT bytes 435570863
STAT limit_maxbytes 536870912

You may want to increase cache size as you are close full it.

Answer 2

It is impossible to say what is wrong with your application, but your memcached usage is not optimal:

STAT cmd_get 171491050
STAT cmd_set 139795434
STAT get_hits 127840250
STAT get_misses 43650800

These numbers mean that 139m items have been stored in the cache. 171m attempts to retrieve items have been performed and of those only 127m items has been found. That means that the likelihood of any item set in the cache to be retrieved is only about 91% (127/139). That is not an effective use of the cache because most of the items stored in it are never used. To me, that suggests you are caching the wrong data. You should try and figure out which data is most frequently used and only cache that instead. Especially if you are running out of cache space often.