[eGroupWare-tracker] Bugs #2700: Error loading some pages occasionally

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Ticket modified by Meelad Meelad at 2010/07/24 12:38
Tracking System: Bugs
Category: News
Version: Version 1.6.003
Status: Open
Resolution: None
Completed: 0%
Priority: 5 - medium
Created By: Meelad Meelad
Assigned to: Ralf Becker
Summary: #2700 - Error loading some pages occasionally
The problem is very strange. It happens with me at the News Admin and the Addressbook pages (News Admin more frequently), but I checked with other people and it appears that some have the exact same problem but with other pages like Project Manager. The problem occurs when I try to open the News Admin page after the first time (or sometimes even for the first time, sometimes the third time...), with internet explorer I get "IE cannot display web page", with google chrome I get "Error 324 (net::ERR_EMPTY_RESPONSE): Unknown error" (also page can't be displayed), and with Mozilla Firefox I just get a blank page (totally blank). In apache2 it produces a "child pid xxxxx exit segmentation fault (11)". The error does NOT happen ALWAYS, but it happens far more often that it doesn't.

Usually when I change some settings (like the theme) I get to open the page once, but when I try to open it another time I can't, until I do something like change a setting or something like that. Rarely I get lucky and can open it for like 5,6,7 times, but then it happens again.

And strangely sometimes only opening the database with phpmyadmin enables me to open the page one more time (not always though), but there is definitely some strange connection between those two events.

Sorry for this VERY long description, it's just that the error is very strange, and very unpredictable. I don't even have a clue about what might be the cause.. But it's a very serious problem for me.. I really hope you can solve it. Thanks. 
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> Comment by Meelad Meelad at 2010/07/24 12:38:
Well your suspicion was absolutely right (I think). It seems I had APC installed. I disabled it through commenting the only line in (/etc/php5/conf.d/apc.ini) which was (extension=apc.so). That little # before that line solved the problem dramatically after restarting apache2. I said dramatically because I have tested it for like 20 minutes, and now I only get that error like once per 10 tries, and when I click refresh I get the page instantly, so it's not THAT annoying anymore.

However to make sure that this isn't a lucky spell, I enabled APC again (through de-commented the line above), and restarted apache2 again, and I got the exact same annoying problem again; I simply could't open the news page. Now I disabled it again, and egroupware is running almost perfectly (bar that very infrequent now "can't open page" error.)

I'll also try to know what caused the problem exactly, and try to fix APC /or install an alternative caching engine, but I guess I can live without the cache in the end if I have to. (Any tips you have are very welcomed).

And by the way, I have installed egroupware (1.6.003-2) on a standard (out-of-the-box) Ubuntu 10.04 server installation, why I think this problem will be encountered more frequently in the coming days, because apparently APC is being shipped as a standard component in Ubuntu Server 10.04..

And as I didn't mention this before, THANKS A TON MAN!
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Comment by Hans-Juergen Tappe at 2010/07/24 10:59:
Could be a segmentation fault of some PHP accelerator / cache, which crashes. Try to figure out if your server has installed one (xcache, eaccelerator) and use the latest version or for debugging, try without.

linked entries:
http://www.egroupware.org/egroupware/index.php?menuaction=tracker.tracker_ui.edit&tr_id=2700&no_popup=1