php and values not returning from memcached
Wed, 2 Jun 2004 18:34:01 -0000 (UTC)

Hi all,

Note: 1st post here so please excuse obvious stupidity but I did read
through the api docs and server docs w/o seeing anything.

I'm running memcached across 3 servers on gentoo linux, kernel 2.6.5
environment (400 megs ram, 100 megs ram, 300 megs ram).

What I'm doing is writing a cache loader to pre-populate a cache of data
pulled from a mysql table.  And what I'm finding is that caching a large
number of items is leaving a handful without values.

My code is using the php API from this:

Basically all I do is loop over my database and call $memc->set($key,
$value, $expire) and then kill the job if $memc returns false.  It never
dies so memcache seems to be accepting all my objects fine.  That works
fine and here's my internal diagnostics at the end of the job:

Total size = 10795847 (this is the sum of the string lengths I loaded)
22734 total objects loaded (this is the total # of keys I sent to memcache)

Now when I go to retrieve the content, I get this result:

err=No value found for key raw_content_47519384

But I know this was set correctly or my code would have died (and my logs
show it was set correctly).  My guess is that objects are being expired
from the cache as new objects come in but I am setting a 5 day expiration
time as measured by a time() + (5*86400) value. And this doesn't seem to
be enough data to overflow a cache of this size.

Here are my stats from the server:
STAT pid 25901
STAT uptime 503
STAT time 1086201062
STAT version 1.1.9
STAT rusage_user 0:118981
STAT rusage_system 0:190970
STAT curr_items 4395
STAT total_items 4395
STAT bytes 2498844
STAT curr_connections 1
STAT total_connections 5094
STAT connection_structures 4
STAT cmd_get 697
STAT cmd_set 4395
STAT get_hits 498
STAT get_misses 199
STAT bytes_read 2454699
STAT bytes_written 338016
STAT limit_maxbytes 524288000

Interestingly I'm finding that the flush_all command isn't working.  That
feeds very, very wrong.

Comments ?  Thanks in advance.