I'm having some strange issues with mod_mono on my server at the moment. Sometimes while using the blog site, my apache2 server suddenly starts giving "server is down for maintenance" errors.

Checking the apache2 error log I'll find an error like this:

[error] (107)Transport endpoint is not connected: write_data failed
[alert] Failed to send initial data. Transport endpoint is not connected

 

This clearly shows that the apache2 process is no longer talking to the mod_mono process. Restart the apache2 server, and you start seeing errors like this:

Failed to destroy the '/tmp/mod_mono_dashboard_XXGLOBAL_1' shared memory dashboard
File exists: Failed to create shared memory segment for backend 'XXGLOBAL'

 

The best information for the problem I've found has been here, but unfortunately no solution as yet.

Hopefully I'll figure it out soon. This particular issue is serverely testing my patience at the moment. So if the blog is down, I appologise, we are attending to the problem :P

Comments

Max
Max
Mon, 26 Nov 2007 #

The same problem and I do not know what to do.

No solution?

Dzugaru
Dzugaru
Wed, 28 Nov 2007 #

Well, I've got the problem with mod_mono and even simple xsp freezing when it works for a while (that gives exactly the same errors as yours), and guess I've found a solution. It occurs when you use ThreadPool, or System.Thread.Timer extensively.

http://www.mono-project.com/ThreadPool_DeadLocks gives an explanation.

In my case, System.Thread.Timer was used by MySql Connector/Net.

http://bugs.mysql.com/bug.php?id=32814

Thu, 29 Nov 2007 #

Dzugaru: I'm not entirely sure that the problems I have are related to a thread pool deadlock, as I've noticed that the mod_mono process consumes up to 80% of system memory before dying. Of course, the memory consumption could be a side effect of a thread pool deadlock, so I will investigate it too. Thanks for the pointers!

Max: No solution yet, but be sure that I will post about it if I find one.

Sat, 12 Jul 2008 #

any solution now? i got the same error message:
/etc/init.d/apache2 restart
Restarting web server: apache2 ... waiting .[Sun Jul 13 16:17:44 2008] [crit] (17)File exists: Failed to create shared memory segment for backend 'XXGLOBAL'

Comments are closed

I am a software developer / architect currently interested in combining .NET technologies with open-source operating systems. 

I am a member of the open-source BlogEngine.NET development team and focus mainly on ensuring Mono compatibility for the project.

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