[Mono-list] mod_mono stability problems

[Michał Ziemski]

Hi!

1,5 gb ram after 800 requests? Seems like you are not releasing your 
objects properly.
Maybe try running with HeapShot (http://www.mono-project.com/HeapShot) 
to diagnose the problem.

I have a site running mod_mono serving ~1k requests/day and have not yet 
seen it allocate more than 100mb.

I can confirm the existence of the latter problem (problem with restart 
- apache returning 503).

Best regards!
Michał Ziemski

Oscar van Tol pisze:
> Hi there and thanks for the advice,
>
>  > > For the past two months we've been hosting a webservice  
> application on
>  > > apache2 and mod_mono.
>  > > Since this week we have some real traffic, and stability issues
>  > > started. We now have about 30.000 requests a day, these make the  
> mono
>  > > process grow in memory usage to about 2gigs. and the response  
> becomes
>  > > really bad.
>  > You might want to increase the thread pool size by setting the  
> MONO_THREADS_PER_CPU
>  > environment variable to a value higher than the default 5 (the  
> formula for
>  > calculating the number of threads in the pool is 20 +  
> ($MONO_THREADS_PER_CPU *
>  > number_of_cpus)
> The application feels a bit faster now, but with a lot of traffic it  
> still sometimes does not come back after the autorestart
>  > > The memory problem is probably cause by the none compacting garbage
>  > > collector, I solved the performance issue by doing an autorestart
>  > > every 400 requests. This works great for a while but after a few  
> auto-
>  > That sounds quite often - I think 1000 would be quite enough in  
> your case.
> With about 800 requests it uses 1.5gb of ram and the performance  
> decreases..
>
>
>  > > restarts it lookes live apache failes to spawn a new mod-mono- 
> server.
>  > > Apache respondes with a 503, when I kill the (old still running)   
> mono
>  > > process and restart apache it's back.
>  > >
>  > > Suggestions?
>  > It's hard to determine what it is just from the description - it  
> might be a
>  > deadlock, might be a memory issue with shared memory. Please  
> compile mod_mono with
>  > - --enable-debug and post apache logs when the 503 happens - that  
> should make it
>  > easier to diagnose what's going on.
> I recompiled on debug, it looks like a deadlock:
> [Thu May 15 23:53:40 2008] [warn] No backend found, will start a new  
> copy.
> [Thu May 15 23:53:42 2008] [warn] Socket file name /tmp/ 
> mod_mono_server_global
> [Thu May 15 23:53:42 2008] [warn] try_connect: -1
> [Thu May 15 23:53:42 2008] [warn] After setup_socket
> [Thu May 15 23:53:42 2008] [warn] No backend found, will start a new  
> copy.
> [Thu May 15 23:53:42 2008] [warn] Acquiring the /tmp/ 
> mod_mono_dashboard_XXGLOBAL_1.lock lock for bac
> [Thu May 15 23:53:42 2008] [warn] Socket file name /tmp/ 
> mod_mono_server_global
> [Thu May 15 23:53:42 2008] [warn] try_connect: -1
> [Thu May 15 23:53:42 2008] [warn] forking XXGLOBAL
> [Thu May 15 23:53:42 2008] [warn] Applications: (null)
> [Thu May 15 23:53:42 2008] [warn] Config file: (null)
> [Thu May 15 23:53:42 2008] [warn] Config dir.: /etc/mono-server2
> [Thu May 15 23:53:42 2008] [warn] Listen port: (null)
> [Thu May 15 23:53:42 2008] [warn] Listen address: (null)
> [Thu May 15 23:53:42 2008] [warn] child started
> [Thu May 15 23:53:42 2008] [warn] PATH: /usr/local/bin:/usr/bin:/bin
> [Thu May 15 23:53:42 2008] [warn] serverdir: /opt/mono-1.9/bin
> [Thu May 15 23:53:42 2008] [warn] PATH after: /opt/mono-1.9/bin:/usr/ 
> local/bin:/usr/bin:/bin
> [Thu May 15 23:53:42 2008] [warn] Started new backend, sleeping 2s to  
> let it configure
> [Thu May 15 23:53:44 2008] [warn] Socket file name /tmp/ 
> mod_mono_server_global
> [Thu May 15 23:53:44 2008] [warn] try_connect: -1
> [Thu May 15 23:53:44 2008] [warn] After setup_socket
> [Thu May 15 23:53:44 2008] [warn] No backend found, will start a new  
> copy.
>
>
>
>
>
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