Re: [squid-users] Performance tunning !

Henrik has told you how to test whether MTU is at fault...It appears you
have not even tried this simple test to confirm the source of the
problem. Perform the test that Henrik has suggested: Configure your
browser to use the proxy rather than using it transparently, and try to
browse the problem sites--if it works, you almost certainly have MTU
discovery problems. Personally, I make it a policy to try whatever
Henrik suggests immediately--he knows more than anybody about just about
everything (or seems to most of the time).

That said, changing the maximum MTU to work around this problem isn't an
"optimization", per se, it is simply fixing a broken aspect of your
network that is caused by the topology and implementation. No
optimization will fix something that is broken...In other words, your
Squid is not too slow, your network is broken. Making Squid or your
system faster will just make errors occur with lower latency. So stop
looking for optimizations, and performance tuning advice and start
figuring out how to fix what is broken! ;-)

Do some reading on MTU. The simplest thing is probably to enforce a
small enough MTU on the cache network interfaces to make the problem
disappear...this probably isn't going to lead to the best performance
(larger MTU leads to higher network throughput and lower load on
equipment, all other things being equal), but it can probably fix the
errors you're seeing.

To read up on the way to set MTU:

man ifconfig

Ling Hwa Hing wrote:
> Hi is there any optimization beside to disable the MTU discovery for the
> box?
>
> Thank you very much for your help!
>
> Best Regards,
> hwahing
>
> 10:34 AM 6/25/02 +0200, Henrik Nordstrom wrote:
>
>> If this is a transparent proxy then you are quite likely bitten by Path
>> MTU Discovery problems between the Squid server and your clients. Try
>> configuring the browser to use the cache. If that helps then you will
>> need to take a crash course in path MTU discovery and why most methods
>> for transparent redirection of port 80 breaks it to determine how to
>> best address it in your network.
>>
>> Regards
>> Henrik

-- 
Joe Cooper <joe@swelltech.com>
Web caching appliances and support.
http://www.swelltech.com