Re: [squid-users] Squid Scalability

On Mon, 06 Apr 2009, Amos Jeffries wrote:

> Ah, sorry I meant CPU load as reported by Squid in %:
>
> "It can be extracted from the "general runtime information" or "info"
> cachemgr page. It's the value marked "CPU Usage" "

I'll hold off until a peak time and check. If it's similar, "top"
generally shows relatively low cpu usage for the squid process.

The munin CPU usage graph also gives a guide (the blue spikes are SRG
running late at night).

http://deathcab.gcd.ie/munin/gcd.ie/watcher.gcd.ie-cpu.html

> Okay, we've reached the edge of my storage-specific performance
> knowledge. I hope someone knows a bit more and can educate us both on a
> good fix :)

Mine too. The operating system is on linux software RAID1 partitions so I
can swap out the smaller disk, pop in a second 1TB disk, sync the OS
partitions and use the remainder as a second large cache. I intend doing
that in the next week or so which should hopefully allow me to up our hit
rate a bit.

I'm not certain yet if the analysis I posted before is correct but if it
is, it would appear a single SATA disk of this sort can only manage about
12-13% with our throughput (150-200GB per day, peaking around 40Mb/sec). I
suspect if I came up with a way to improve our hit rate further (eg youtube
caching), the iowait trouble would just get worse. Hopefully a second disk
will allow this to expand further. After that, I guess I'll have to look
at a new server.

Gavin
Received on Mon Apr 06 2009 - 09:29:09 MDT