Re: [squid-users] speeding up response

From: Joe Cooper <joe@dont-contact.us>
Date: Sat, 08 Jun 2002 04:06:58 -0500

Mark is quite right, but I'll add a couple of comments...

Generally, when someone says something like "Browsing with Squid feels
sluggish, why is proxying slow?" or similar, it usually is not in fact
the unavoidable proxy latency that they are seeing (which is extremely
quick in a properly configured Squid) but instead simply a
misconfiguration somewhere on their network. As Mark mentioned, the
most common problem is DNS latency--slow DNS equals high latency.

Browsing /should/ feel faster with Squid, on average, than without it.
And when properly configured browsing does feel notably quicker (because
a 0.02 second response time is nicer than a 1 second response time, and
this is even more noticeable on a local ethernet). If it does not, the
right question for the list is probably more along the lines of "How do
I track down what is causing high latency when browsing through my
Squid?" Because when everything is working right, Squid doesn't really
adversely impact misses by a noticeable amount (though it is a
measurable amount, but very small) and makes cache hits 10 or 20 times
quicker.

So, as Mark says...Look into that DNS. You can check how long lookups
are taking for Squid by checking with the cache manager general info page:

client mgr:info

Look for the "DNS Lookups" field. These should be under a tenth of a
second, or even faster, generally.

Mark Tinka wrote:

> what i have noticed, however, DNS resolution is the
> one of the most latent parts of using squid... to
> reduce the effects of this, i have done several tests
> with DNS servers, mostly BIND 8.2.4, and transparent
> caching, and discovered that it becomes a lot faster
> for u and your cache when u are both using the same
> DNS server on the same subnet/network to resolve
> domain names.... the issue is, when your client
> computer sends a request to the DNS server for say,
> www.hotmail.com, it will wait for a response from the
> DNS server with an IP address.. once that has been
> provided, the client machine will then connect to the
> squid server, and the squid will then go thru the same
> process the browser went thru.... now, if your client
> DNS server setting matches that of the squid.. squid
> will find the DNS record[s] already cached in the DNS
> server [especially if u are running NSCD - name
> service cache daemon - ] which will reduce the time it
> takes squid to resolve the same name... squid will
> immediately connect to the IP address and display the
> default or requested page....

> --- Kay Joplin <err0r@lunastraat.homeip.net> wrote: >
> hi folks,
>
>>is there any way to have the pages appear instantly
>>on the screen, the way
>>they normally would without proxying ?
>>
>>thnx,
>>
>>KJ

-- 
Joe Cooper <joe@swelltech.com>
Web caching appliances and support.
http://www.swelltech.com
Received on Sat Jun 08 2002 - 03:07:59 MDT

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