Re: [squid-users] how to speed up squid

On Mon, 2005-10-10 at 16:21 +0600, Tharanga wrote:
> Greetings!
>
> I have installed a squid 2.5 and but my clients are always complaing that
> the internet access speed is very slow. iam using 1 GB RAM and i incresed
> cache siz to 340 MB. (approx 1/3 of physical memory.)
> is there any other parametes to increasse the speed of my proxy server ??
> please help me to solve this matter..

Users will _always_ complain that Internet accesso is slow. The problem
is: can they be trusted? Rarely. And the general availability of
broadband at home has, if anything, made users even less reliable as a
source of performance information.

The first step is to quantify and measure the problem, since users
almost always have a subjective (and not quantitative) view of what's
going on.

Try a simple test: on a test client system with enough network access
permissions, try accessing a test site or three of your choice, using a
test pattern such as: clear browser cache, close all browser windows,
open browser, access site without using the proxy, clear browser cache,
close all browser windows, configure proxy, access site. Is there any
noticeable performance difference?

It might not be a problem with squid, especially if there is no
performance difference.

First: check cache.log, and look if it says anything strange, such as
squid restarting unexpectedly or complaining about some resource being
unavailable.

Check your uplink congestion rate. Is it congested? Squid can help with
a congested uplink, but can't perform miracles. What about latencies? Do
a traceroute to a test site and check what is the performance on the
first two-three hops: the problem might not be with your uplink, but
with your provider's.

Check your system performance: how much CPU time it spends running
Squid, how much in the kernel, how much iowait, how much swap it is
using, pagein and pageout rates, etc. The system must be in a sane state
for squid to have a chance to perform. Increasing cache_mem can actually
be detrimental to overall squid performance if you end up using more
memory than your system can give you: parts of squid end up being
swapped in and out trashing performance..

If you found nothing so far, fire up your cachemgr and look for
performance indicators such as hit ratio (memory, object and DNS), DNS
response time, number of available filedescriptors. If you're using
authentication check the authenticators' queues congestion - all these
things add latency to a request handling, and that can generally make an
user's browsing experience much worse.

Repeat the analisys at different times in different days, check for
variations in the vital parameters.

Collect a few days' worth of logs, and run on them a statistics software
such as calamaris or webalizer, and start looking for deviations from
"reasnonable" behaviour, such as users with unreasonably high bandwidth
or request usages.

Only at this point you should have a clear enough picture to know what
knob to turn in order to fix your problem. if there really is a problem.

        Kinkie
Received on Mon Oct 10 2005 - 06:21:31 MDT