[squid-users] Re: RPS

Hi Liley,

The only tool I used was AB (Apache Bench), you can use it to generate a lot
of traffic; albeit from a single source IP. So basically you run AB with the
desired number of connections (concurrency) and the maximum number of
requests to send. Take note of the AB output as well as monitor your Linux
system (SAR stats would be useful, and possibly ntop), then tweak your Linux
kernel settings, and run the test again. Compare the output and if after
tweaking there is room for improvement (i.e. memory & cpu utilisation as
well as response time remain stable) then tweak and test again.

The final tests that were run on my box (in which it achieved ~2000 conns
per second) was done so using an enterprise grade test solution, the tests
were left to run, continually ramping up traffic (i.e. simulating more user
connections). The test aimed to total up millions of page views over the
course of 3 hours. I think the server actually out-performed these test
results when it was put into production, I recollect it handling upwards of
60,000 established connections (and remaining stable).

There is no best way to determine what settings to use, other than trial and
error, do the testing, tweak and test again and see if the results are
moving forward.

Also, just on a side note when handling a large amount of traffic like this
you need to ensure collapsed_forwarding is enabled, when your content goes
stale and you have thousands of users all trying to get it at once you can
flood your back end, collapsed_forwarding will ensure only a single request
is sent to the back end server.

Another side note, you should consider using 'stale-while-revalidate=120' on
your refresh_patterns, this means that Squid will serve stale content for 2
minutes; very useful if your back end has come under heavy load.

Hope that helps
Gareth

-----
Follow me on...

My Blog
Twitter
LinkedIn
Facebook

--
View this message in context: http://squid-web-proxy-cache.1019090.n4.nabble.com/RPS-tp4480226p4503459.html
Sent from the Squid - Users mailing list archive at Nabble.com.