Re: [squid-users] TCP_MISS/502 Issue

On 18/02/11 08:03, Gabriel Marais wrote:
> hi guys
>
> i am trying to understand the TCP_MISS/502 issue. I have many proxy
> servers in production, all running ubuntu server 8.x to 10.x
>
> in particular, i have one proxy server that has come up with the
> TCP_MISS/502 POST error. Internet Explorer just comes up with "Internet
> Explorer cannot display the web page" and the only error in Squid is the
> _MISS/502 POST error.
>
> on my other proxy servers, the web site displays without any problems
> and their network setup is the same in terms of iptable rules. initially
> i thought it could be a squid version problem, but i have loaded the
> exact same version of squid on the server giving the error as another
> squid server that is working.
>
> can anyone make heads or tails from the cache log below and possibly
> guide me with the other things to possibly check ?
>
>
> thanks in advance, gabriel
>

There are several GET and POST being handled in parallel for the same
URL. Its a little hard to tell them apart. Just to confuse matters there
are some earlier existing requests for POST and GET of the same URL
finishing during the trace.

The first identifiable POST is FD 16, being sent out to the server.

<snip>
> 2011/02/17 20:27:02| fwdConnectDone: FD 17:
'http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:27:02| fwdDispatch: FD 16: Fetching 'POST
> http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:27:02| httpStart: "POST
> http://www.sarsefiling.co.za/Default.aspx"
> 2011/02/17 20:27:02| httpBuildRequestHeader: Referer:
> http://www.sarsefiling.co.za/Default.aspx
> 2011/02/17 20:27:02| created entry 0x8405200: 'Referer:
> http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:27:02| httpBuildRequestHeader: Host: www.sarsefiling.co.za
> 2011/02/17 20:27:02| created entry 0x8422480: 'Host: www.sarsefiling.co.za'
> 2011/02/17 20:27:02| getMaxAge: 'http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:27:02| destroying entry 0x8405200: 'Referer:
> http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:27:02| destroying entry 0x8422480: 'Host:
> www.sarsefiling.co.za'
> Referer: http://www.sarsefiling.co.za/Default.aspx
> Host: www.sarsefiling.co.za

<snip...>

> 2011/02/17 20:29:08| fwdServerClosed: FD 17 http://www.sarsefiling.co.za/Default.aspx
> 2011/02/17 20:29:08| errorConvert: %U --> 'http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:29:08| errorConvert: %U --> 'http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:29:08| clientSendHeaders: FD 16 'http://www.sarsefiling.co.za/Default.aspx'
> 2011/02/17 20:29:08| The reply for POST http://www.sarsefiling.co.za/Default.aspx is ALLOWED, because it matched 'all'
> 2011/02/17 20:29:08| storeSwapOut: http://www.sarsefiling.co.za/Default.aspx
> 2011/02/17 20:29:08| storeSwapOut: http://www.sarsefiling.co.za/Default.aspx
> 2011/02/17 20:29:08| fd_close FD 17 http://www.sarsefiling.co.za/Default.aspx

It appears to be that FD 16 is the client FD and FD 17 is the server FD
setup for one of the POST.

  Assuming that is correct I come to the conclusion that Squid is
accepting a POST, locating a server to handle it and passing it on. The
server then actively closes the TCP link. There is no information about
data received back.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.11
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