Re: [Pound Mailing List] Gradual slowdown

We did a bit of coding recently on the 2.7c source for internal use.  In
the process we found out things get a bit odd when the browser sends a
keep-alive directive.  By odd I simply mean it was kept alive on subsequent
requests several seconds later than I would have expected.  You might want
to review your load test and see if it using the same keep-alive
information that your normal clients are and if your load test framework
matches browser behavior for keep-alive.  That doesn't answer your question
for Pound but it might give you insight into the difference in results.


On Fri, Aug 29, 2014 at 3:02 AM, Jonathan Roberts <jonrob.one-gM/[email protected]
> wrote:

> Hello,
>
> We are in the process of moving to Pound as our load balancer, and while
> it passed functional testing and worked fine in front of internal users,
> when putting it in front of external users, we had to roll back due to a
> gradual slow down in our site's response times. After approximately half an
> hour, the site became unusable. We're struggling to identify the cause.
>
> Our first thought was that the slow down came as we use cookie based
> sessions to one of our backend pools. In the half hour it was in front of
> customers, we generated a lot of sessions. We ruled this out by load
> testing it, creating a similar number of sessions, and the site remained
> responsive.
>
> In the course of load testing, we ran in to issues with ulimit and max
> number of open files, as indicated by the Pound log. Reviewing the logs
> from the external deployment, however, we don't see any corresponding log
> messages, so we don't think this is the cause.
>
> We don't think it can be volume of traffic related. Our current load
> balancer handles our traffic fine, memory and cpu utilisation of the Pound
> server throughout the half hour look fine, and we're only serving in the
> region of 2 - 300 TCP requests per second.
>
> We have Pound doing SSL decryption, and have recompiled it using
> --with-maxbuf=16384 to overcome an issue with some users having extremely
> large HTTP headers (large cookies from Google analytics).
>
> It looks like the problem manifested as failed connections, with no http
> response being returned.
>
> At a bit of a loss as to where to go next. Any advice would be warmly
> received.
>
> Jon
>



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David Martineau
CTO
ContractPal, Inc.
801.494.1861 x120
david.martineau-A5OpC/[email protected] <e.david.martineau-A5OpC/[email protected]>