File storage problem.
cosimo at streppone.it
Mon Apr 12 21:56:37 CEST 2010
In data 12 aprile 2010 alle ore 10:33:04, Sébastien FOUTREL
<sfoutrel at bcstechno.com> ha scritto:
> We use Varnish 2.0.6 in a production site that do about 100Mb/s and 1K
> Hits/s per cache.
> We found a strange phenomon when we added some 24H TTL to images.
> The file storage seems to have some garbage collection that deeply
> impact performances when freeing some large amount of cache.
> We initialy used 8Gb file storage and encountered some GC at about 80%
> usage that freed almost all file storage (monitored with cacti using
> sm_balloc,sm_bfree values).
> We tried on one of our cache to test with 32GB and 64GB files but same
> happened even worse because on the 64GB file it did the GC at 30GB and
> freed until sm_balloc reached 2GB.
> We do not understand what is that and and to control it so if someone as
> ideas around that problem ?
I'm not sure you have the same problem I experienced,
but it looks very much like the same.
Read this mail from the archives, especially the "CPU IO wait" paragraph,
it's very old as it refers to 1.1.2, but as soon as we switched to
the "malloc" storage as suggested there, all iowait/load problems
magically disappeared. See also here:
We're not using any swap, as we have servers with enough ram to keep
a useful share of the file set in memory.
I think it's worth a try.
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