RE: [squid-users] cache_swap_low and high waternmark

From: Jigar Rasalawala <[email protected]>
Date: Wed, 30 Apr 2003 14:30:00 -0700

Hi, Henrik

*** You still have not answered how much traffic you are trying to push
via Squid.

I am working on it. I will send u in next mail.

Just for curiosity,
Is there any way to prevent low water mark condition ? If I can check remaining
free disk space using SNMP, and before it hits 90% If I delete or drop cached objects
from cache. Than may be I never this low water mark condition.

Is there any way to delete or drop objects from cache ( not entire cache ) ? I know
about PURGE method, it will remove one object at a time. Does it support wild card ?

Any suggestion or hint or any alternative appriciated

Thank you in advance
Jigar

-----Original Message-----
From: Henrik Nordstrom [mailto:hno@squid-cache.org]
Sent: Tuesday, April 29, 2003 11:55 PM
To: Jigar Rasalawala
Cc: squid-users@squid-cache.org
Subject: Re: [squid-users] cache_swap_low and high waternmark

On Wednesday 30 April 2003 02.42, Jigar Rasalawala wrote:

> According to the docs, When squid reaches upto high watermarks, it
> will try to maintain disk space between low and high watermark.

Yes, and it does.

What it does not do is to wait for the usage to reach the high water
mark before starting to clean up. Instead the closer to the high
water mark the more aggressive it deletes objects.

> While releasing objects from squid does not serve any HTTP
> request... It hurts performance.

On the contrary, by spending time when there is no requests to delete
objects performance is increased, as Squid then do not have to delete
objects at the same time as processing a request.

> I think If low and high watermark scenerio works, then
> squid will release object frequently but on at every second..

This would seriously impair performance. Every second Squid would need
to spend a lot of time on deleting objects, seriously impairing the
performance of requests at the time.

For Suqid performance you want an even and smooth performance, not
randomly blindingly fast and crawling.

You still have not answered how much traffic you are trying to push
via Squid.

Regards
Henrik

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Received on Wed Apr 30 2003 - 15:30:39 MDT

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