Question

After upgrading to 20040902 version, several users have reported saves and attachment uploads taking forever. Several of these users are remote, connecting to the corporate LAN via VPN, but one "internal" user has also experienced the slow saves. These users had no trouble saving before the upgrade. One puzzling thing is that most users are not experiencing slow saves.

The only new plugin added to the new install was the XpTrackerPlugin (and its supporting plugins).

I have done some debugging, watching both the Apache log and the output of tcpdump during a slow save. The tcpdump shows activity, but not the Apache log.

The server does not seem to report any spike in CPU activity, nor any Apache or TWiki process taking a lot of system resources.

The machine is a 2.8 GHz, 1-CPU, with 1 Gig of Ram - plenty of power for the traffic on this server. There are aprox. 150 registered users, and less than 20 concurrent users.

I have reviewed topics SaveForever, IncreasinglyPoorPerformance, and XpTrackerPluginProblems. None of the suggestions have helped our situation. I've also seen other posts around the web, but no help there either.

Suggestions for debugging or resolving the issue would be great.

Thanks, DonSmith

Environment

-- DonSmith - 09 Feb 2005

Answer

is it browser specific? I have a problem, which nobody else seems to have, with some particular configurations, not yet identified, of Internet Explorer. While Firefox, Mozilla and Opera users have no problem at all. Read WhatsWrongIE for much confusion and no answers.

One thing which seems to help IE users is to turn off HTTP 1.1 (under Advanced Options).

-- MattWilkie - 09 Feb 2005

The problem occurs with both IE and FireFox. Our version of Apache may have something to do with it (2.0.48), see TWikiOnApache2dot0Hangs.

We upgraded to Apache 2.0.53, on a much more powerful server, and things seem better. But I experienced a browser hang after the upgrade. One work-around is to hit the stop button, then try again.

-- DonSmith - 14 Feb 2005

Just got a report from a user of browser hanging during upload of an attachment. So it looks like the upgrade of Apache didn't do us much good after all. Bother...

-- DonSmith - 14 Feb 2005

Several users who connect via VPN are having trouble uploading attachments. No reports from internal users yet.

• Possible answer in AttachmentProblems

-- DonSmith - 16 Feb 2005

Looks like the same issue as UploadAndSaveHangingForever, although that issue was reported in the 20041024 beta, not the 20040902 release.

-- DonSmith - 23 Feb 2005

Don, I may be seeing the same thing on Cairo. I've looked at UploadAndSaveHangingForever, and my Prefs.pm doesn't look like the one mentioned around line 412. Did you get this problem fixed on Cairo, and if so, can you share it ?

-- SteveJonesST - 20 May 2005

I met the same problem too. Anybody already fix it???

-- KarlLiu - 04 Apr 2006

I had a similar problem and the fix posted on Apr 20 by Doug Caar at this site seemed to have fixed the problem. (http://twiki.org/cgi-bin/view/Codev/TWikiOnApache2dot0Hangs)

-- AndreCharbonneau - 24 Apr 2006

I am still having the problem on Apache 2.2.3 as well as 2.0.48. The problem only started occurring after upgrading to 4.0.4 from 9/2004 version.

The problem is similar to what's described above but not browser specific. tcpdump shows constant retransmission of packet 1 during the delay, but I don't know how to read tcpdump output so I can't tell what's really going on. (If anyone wants to see the output I'll send it to you)

-- BillKayser - 14 Sep 2006

I did find a workaround for 4.0.4. Lowering the network timeout in Apache from a default of 300s to something less annoying like 20 seconds alleviated the problem a great deal. I don't know whether that's a good idea in all cases but we only access the site locally and it did not seem to have any ill effects.

The directive is TimeOut.

-- BillKayser - 07 Oct 2006