Re: [squid-users] Squid cutting off download of files and media issues

 On Wed, 23 Mar 2011 10:51:00 -0600, Bobby wrote:
> Hello all.
>
> I've been having trouble figuring this out so. Thought I'd ask the
> experts!
>
> Using Squid 2.7 with no ACL's configured to block media or file
> extensions for download. When users try to download a .PDF for
> example; the download will start and then hang about halfway through.
> After hanging for a minute or so the download box will disappear,
> when
> the file is checked as you might guess it is incomplete. On occasion
> I
> can just click on the file to download and it will complete
> successfully. More times than not though it will just never work and
> I
> have to bypass the proxy to download the file. I have similar issues
> with flash and other types of video content. As an example: I can go
> to CNN or Youtube and click on a video file, the file will start to
> play and then just stop.. Hanging as long as I leave the page open.
> As
> a test I've left the page up all day before and sometimes it will
> just
> start playing hours later, sometimes it never restarts..
>
> Another problem I've noticed that may be related; this hang seems to
> happen even on a regular web page such as google.com. I launch the
> browser and go to google, the page loads but the browser is
> unresponsive (progress bar sticks about ¾ of the way across) 30
> seconds to a minute later the progress bar hits 100% and the page and
> browser are responsive. I have noticed that during a page hang like
> this if I am logged into the squid box (Debian Lenny) and I issue a
> "rndc flush" command the progress bar completes to 100% and the page
> is immediately responsive.
>
> Any ideas?

 Is the request speed going through this proxy under 1 or 2 per second?
 That hanging behaviour reminds me of a scheduling issue older Squid had
 under very low traffic (ie only one client).

 The other common problem with largish files is window scaling or ECN
 problems. Where one end of the connection would work until it increased
 the TX window to a certain size, then an ICMP control message would
 disappear and everything would hang.
  http://wiki.squid-cache.org/KnowledgeBase/BrokenWindowSize

 The incomplete PDF issue is identical to one I'm struggling with myself
 for one client. It seems to be occasional (1 in 10 or so) and something
 to do with the Acrobat fetch algorithms for us though.

 HTH
 Amos
Received on Wed Mar 23 2011 - 21:49:14 MDT