Re: [squid-users] url length limit

Gregori Parker wrote:
> Hi all - I am using an array of squid servers to accelerate dynamic
> content, running 2.6.22 and handling a daily average of about 400
> req/sec across the cluster. We operate diskless and enjoy a great hit
> rate (>80%) on very short-lived content.
>
> About 50+ times per day, the following appears in my cache.log:
>
> squid[735]: urlParse: URL too large (4738 bytes)
> squid[735]: urlParse: URL too large (4470 bytes)
> squid[735]: urlParse: URL too large (4765 bytes)
> ...
>
> I understand that Squid is configured at compile time to cut off URLs
> larger than 4096 bytes, as defined by MAX_URL in src/defines.h, and that
> changing this has not been tested. Nevertheless, since I am expecting
> very long URLs (all requests are long query strings, responses are
> SOAP/XML), and the ones getting cutoff are not severely over the limit,
> I would like to explore this change further.
>
> Has anyone redefined MAX_URL in their squid setups? Do these 'URL too
> large' requests get logged? If not, is there a way I could get Squid to
> tell me what the requests were so that I can verify that we have an
> operational need to increase the URL limit?

It has been tried at 8192 with no sign of trouble in Squid-3.
If your URL get much large than that, we really do need it checked up as
high as 128KB so feel free to build with larger values, just please
report back how it goes (particularly if good news).
http://www.squid-cache.org/bugs/show_bug.cgi?id=2267

I'd suggest experimenting with squid 3.1.0.1 to see if its usable in
your setup. The URL limits have been raised to 8KB already and diskless
operation is much more polished and native.

As for logging the URI, most things in squid are dropped when they are
found to overflow the buffers like that. The details may be logged to
cache.log when debug_options is set to the right section and level. I'm
not sure right now which one is relevant to 2.6 though, there are a few
available.
http://wiki.squid-cache.org/KnowledgeBase/DebugSections

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE5 or 3.0.STABLE10
   Current Beta Squid 3.1.0.1