Upgrading to 3.1.0.7 beta seems to have resolved most of the youtube timeouts I was seeing. Thanks for the suggestion, Amos.
- harv -----Original Message----- From: Amos Jeffries [mailto:[email protected]] Sent: Thursday, April 09, 2009 9:32 PM To: Harvey Dueck Cc: [email protected] Subject: Re: [squid-users] FW: timeouts when proxying youtube Harvey Dueck wrote: > I am running squid 3 on Fedora 10. > > Something is causing an unreasonable number of timeouts when clients access > high definition videos on youtube through the proxy. > > I am not trying to cache or otherwise manipulate the youtube content. > > The symptom is that the video always starts transferring OK, but sometimes it > hangs partway through. > > Wireshark initially showed that there was a problem with tcp window scaling. > Changing the linux config to reduce the max window size or even disable > scaling got rid of most of the timeouts, but the frequency of timeouts when > using the proxy still greatly exceeds the frequency of timeouts when the > proxy is not used. > > When I don't use the proxy, I see maybe one or two timeouts in fifty > downloads. Using the proxy, I see maybe 25 timeouts in 50 downloads, i.e. > half the time it doesn't work. > > I took a look at > http://inodes.org/blog/2006/09/06/tcp-window-scaling-and-kernel-2617/ for > discussion of the window scaling issue and > http://squidproxy.wordpress.com/2007/06/05/thinsg-to-look-at-if-websites-are-hanging/ > for some general hanging discussion. > > I don't think that ECN or MTU issues are the culprit here, though I will do a > bit more investigation. > > Does anyone have any other bright ideas about why youtube in particular might > present this problem? And only with HD videos; the normal definition videos > all seem to load fine (15 timeouts in 340 trials). > > Thanks in advance, > > - harv > Using 3.0 or 3.1? the flow events handling is much improved between the two. Amos -- Please be using Current Stable Squid 2.7.STABLE6 or 3.0.STABLE13 Current Beta Squid 3.1.0.6
