RE: [squid-users] tune up

If you're referring to my postings about a month ago, I've been doing some
further tests after getting some pointers from different people, and the
results are different.

We have a number of sets of proxies in different locations, each set being
load-balanced using wccp and layer 3 switch. My results were different when
comapring caches with lower loads (Avg 39 req/sec, peak 70 req/sec) than
when I was comparing caches with higher loads (170 req/sec avg, peak
>300req/sec).

I was using the aufs cache_dir type, as I have found this to be
significantly faster than diskd when running on linux. The different
paramaters that I was comparing were the load average (with aufs, as disk
i/o increases, there will be more threads waiting on disk i/o, which will
push the load average up), the disk utilisation (% time each disk had active
operations) and cpu utilisation.

I found that under low loads, ext3 mounted with data=writeback (the same
level of data protection as other journalled filesystems) gave the best
numbers (ie lower CPU, lower disk utilisation and lower load average.

I found that on our more loaded systems, reiserfs had lower disk utilisation
and a lower load average, at a slight cost of CPU time.

So, if the disk i/o is going to be a bottleneck (as it is in our case),
reiserfs is probably a better choice. If CPU is the main bottleneck, then
ext2/3 may be the best choice.

It also looks like reiserfs may use more resources under low load, but
scales better at the higher loads. This confirms the results of previous
benchmarks that show reiserfs to provide the highest throughput for a squid
proxy server (using the Web Polygraph program).

Steven

> -----Original Message-----
> From: Wennie V. Lagmay [mailto:wlagmay@yanbulink.net]
> Sent: Monday, May 30, 2005 12:49 PM
> To: Henrik Nordstrom
> Cc: Henrik Nordstrom; azeem ahmad; squid-users@squid-cache.org
> Subject: Re: [squid-users] tune up
>
> Another question, regarding file system, Im using reisersfs
> for my cache
> partition and I've read that ext3 is faster than reiserfs, If
> it so, is
> there a way or an option to make reiserfs as fast as ext3?
> what are the
> parameters to be used for fstab to make reiserfs fast?
>
> In your experience which is the best file system for squid?
>
> Thank you very much,
>
> wennie
> ----- Original Message -----
> From: "Henrik Nordstrom" <hno@squid-cache.org>
> To: "Wennie V. Lagmay" <wlagmay@yanbulink.net>
> Cc: "Henrik Nordstrom" <hno@squid-cache.org>; "azeem ahmad"
> <azeem81@msn.com>; <squid-users@squid-cache.org>
> Sent: Saturday, May 28, 2005 6:41 PM
> Subject: Re: [squid-users] tune up
>
>
> > On Sat, 28 May 2005, Wennie V. Lagmay wrote:
> >
> >> Its only now that I knew this cache_dir issue, Im using
> FC2 64 bit and
> >> using diskd for my cache_dir. Is ther a way to migrate my
> cache_dir to
> >> aufs without harming my cache server.
> >
> > Yes. Modify squid.conf and restart your Squid.
> >
> >> cache_dir aufs /cache1/spool/squid 25000 16 256
> >> cache_dir aufs /cache2/spool/squid 25000 16 256
> >> cache_dir aufs /cache3/spool/squid 25000 16 256
> >
> > Regards
> > Henrik
>
>
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