Re: [squid-users] 502 Bad gateway

On 13/10/2012 2:18 a.m., Leonardo wrote:
> Hi,
>
> I'm getting "502 bad gateway" while attempting to access the site
> ibs.it. This happens with squid 3.2.2 and 3.2.0.19 at least. It does not
> happen with squid 2.7.x series (not tested with all minor revisions
> though).
>
> Anyone else getting the same error?

Beyond the generic HTTP status code what else do you have? Squid logs
and the content of that 503 response would be helpful.

>
> I've dumped the traffic with squid and without squid (it works without
> proxy), and as far I could tell, there's no reverse proxy doing bad
> stuff.

It's not about a reverse proxy. It's about something somewhere in the
relay chain not being available. The error page itself will tell more.

> The answer from the site appears to be same in both cases. With
> squid, I see that after the second response packet, after the GET
> request, my proxy closes the connection with FIN,ACK, and all subsequent
> response packets get an RST.

Sounds perfectly normal behaviour for TCP shutting down a connection.

But are you saing the proxy sends FIN or FIN+ACK ? which one determines
which end is doing the closure.

>
> What could it be the issue?

One of the services needed by Squid to provide a response is not
working. Upstream HTTP server, DNS server, ICAP server, helper problem,
TCP errors, URL scheme unknown, .... could be any one of those or
something else entirely.

Amos
Received on Sat Oct 13 2012 - 05:05:26 MDT