[squid-users] HTTP 503 Meaning

[Amos Jeffries]

On 2/09/2016 11:37 a.m., vze2k3sa wrote:
> Hi,
> 
>  
> 
> I'm looking for a little help. The Squid access log line below show an http
> 503 error. Does this mean that Squid received a 503 from the server it
> connecting to or does it mean Squid itself is too busy at the moment to
> service the request?
> 
>  
> 
> 01/Sep/2016:17:20:24 -0400  21044 192.168.59.196 TAG_NONE/503 0 CONNECT
> www.website.com:443 <http://www.website.com:443>  - HIER_NONE/- -
> 

The HIER_NONE means that no server was involved with that transaction.

So therefore the 503 was generated by the Squid logging that entry.

Given that it waited for 21.044 seconds before generating the failure
response. I interpret that as either DNS lookups taking too long, or TCP
timeouts when sending the initial TCP SYN packets.


> 
> Also, does anyone know of a better more preferred log pattern than the one
> shown above? Maybe one that might supply even more details for any/all cases
> not just the one above?

The Squid native format is better. It gives you millisecond time
resolution for tracking transactions.

Otherwise you need to decide what details you want to record and build a
custom log format. The available options are fairly comprehensive
(though there are some holes depending on your Squid version).

Amos