Re: [squid-users] Is Squid Resilient?

mån 2006-03-20 klockan 16:30 +0000 skrev Neil Mc Lysaght:
> Hi all,
>
> Slight Problem here..
>
> I have installed and configured squid hoping that it would provide a
> level of resillience in the event a destination server 'goes down'.
>
> Currently I have 2 squid proxies running each configured to recognise
> the other as a peer sibling.
> Each of the quid proxies is configured to use the same destination
> host configured as httpd_accel host port etc
> The Content being serverd by the destintation server sends a
> max-age/expires header in its response.

For best results you should try to also send a Last-Modified, and even
better if you server can make use of this in If-Modified-Since...

> My problem is that I would like the Squid proxy to continue to serve
> content even if the destination server is not available.
> Is this possible.

It is supposed to do so if the content is refreshable, i.e. haves a
Last-Modified header.

> but If the destiantion is not available, everything hangs and
> eventually times out.

See connect_timeout and forward_timeout. You want to tune both down in
an accelerator setup.

Also better results is most likely seen if you use cache_peer based
request routing, using the web server as a peer. This allows Squid's
built-in peer monitoring to more gracefully handle the situation where
the host is down.

Regards
Henrik