Hi debianers, I've contacted squid's upstream to help clarifying some details in this thread and am now forwarding Amos' reply:
> Thanks Luigi, you may have to relay this back to the list. I can't seem to > post a reply to the thread. > > > I looked at that Debian bug a while back when first looking at optimizing the > request parsing for Squid. With the thought of increasing the Squid threshold > for pipelined requests as many are suggesting. > > > There were a few factors which have so far crushed the idea of solving it in > Squid alone: > > * Replies with unknown-length need to be end-of-data signalled by closing the > client TCP link. > > * The IIS and ISA servers behaviour on POST requests with auth or such as > outlined in our bug http://bugs.squid-cache.org/show_bug.cgi?id=2176 cause > the same sort of problem as above, even if the connection could otherwise be > kept alive. > > This hits a fundamental flaw in pipelining which Robert Collins alluded to > but did not explicitly state: that closing the connection will erase any > chance of getting replies to the following pipelined requests. Apt is not > alone in failing to re-try unsatisfied requests via a new connection. > > Reliable pipelining in Squid requires evading the closing of connections. > HTTP/1.1 and chunked encoding shows a lot of promise here but still require a > lot of work to get going. > > > As noted by David Kalnischkies in > http://lists.debian.org/debian-devel/2010/05/msg00666.html the Squid > currently in Debian can be configured trivially to pipeline 2 requests > concurrently, plus a few more requests in the networking stack buffers which > will be read in by Squid once the first pipelined request is completed. > > A good solution seems to me to involve fixes on both sides. To alter the > default apt configuration down to a number where the pipeline timeouts/errors > are less likely to occur. As noted by people around the web 1-5 seems to work > better than 10; 0 or 1 works flawlessly for most. While we work on getting > Squid doing more persistent connections and faster request handling. > > Amos > Squid Proxy Project Regards, L -- Luigi Gangitano -- <lu...@debian.org> -- <gangit...@lugroma3.org> GPG: 1024D/924C0C26: 12F8 9C03 89D3 DB4A 9972 C24A F19B A618 924C 0C26 -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/bbef7628-d6e3-4312-8669-e0ada34b2...@debian.org
