Re: [squid-users] Heavy load

From: Henrik Nordstrom <hno@dont-contact.us>
Date: 21 Feb 2003 14:28:13 +0100

fre 2003-02-21 klockan 14.00 skrev kris:

> no raid level, only the controller each disk separatelly

Good.

> 3, one system and two adre cache disks

2 cache disks is not sufficient for the load you are trying to push I
think. At least not unless these drives are solid state drives with no
moving parts which takes time to move.. seek time is a big issue for
Squid performance.

Having a raid controller with onboard cache memory may help a little,
but only marginally. The OS also caches aggressively in memory.

> > And when did your cache become filled? There is a significant
> > difference in performance between an empty cache being filled and a
> > cache which is full and being recycled..
>
> just after start, after validation procedure, and all the time,

This does not answer the question.

The question I am asking is how long have you been running Squid, and at
what point in time did your cache_dirs get fully populated with cached
objects?

When you first installed Squid the cache was empty. Then as Squid is
used more and more objects is cached. When the size of your cache_dirs
have been used Squid needs to start recycle space in your cache dir
which makes a significant negative impact on disk I/O performance.

-- 
Henrik Nordstrom <hno@squid-cache.org>
MARA Systems AB, Sweden
Received on Fri Feb 21 2003 - 06:28:27 MST

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