Re: [squid-users] Load

25-Mar-02 at 15:21, General Manager - Keyworld Ltd (mailing@keyworld.net) wrote :
> It is a P3 1 Ghz with 512 Mb RAM and a single 40Mb 5400 rpm IDE Hard drive.
>
> Over the past three days, the box died twice without any apparent reason
> being recorded on the logs. It stopped responding to a ping and obviously
> browsing was down for all the network. Then the service came back up of its
> own accord and the machine starting answering pings once more.

Well, if it is not responding to pings, we can reasonably assume that it
is not the Squid process dying, but TCP/IP I/O which is going down. This
could be a network card issue, especially if it is auto-sensing and
switching between 10/100 all the time. I have had this issue on boxes
before.

However, this could be an overload problem. On IDE there could be
something crashing as well, if you have a high amount of requests/sec and
the IDE is somehow not keeping up.

What other pertinent information can you dig up from system logs at the
time of failures? I can't think of anything immediately without more
evidence.

For the high load question, here are a couple of nuggets from January's
archives:

On Wed, Jan 16, 2002 at 09:17:11AM +0100, Chemolli Francesco (USI) wrote:
> My box (single P2/450) with 6 9GB 7.2Krpm U2SCSI drives does 30 Gb/day,
> with the CPU constantly over 85% during peak hours.

<robin.stevens@COMPUTING-SERVICES.OXFORD.AC.UK>
> On our systems (PIII-1000, 1.5GB RAM, 7x18GB 10krpm U160 drives), I've
> pushed 10 million requests and 60GB per day through them at peak request
> rates of around 220/sec, though this was close to the limit. I suspect we
> might do a little better if most requests were not sent to a parent cache,
> and that our newer systems with faster CPU, 15krpm disk and more RAM could
> do a little better. I believe around 300 requests/sec is about the
> fastest any single instance of a stable squid release has been pushed.

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