[Opensim-dev] Question about Threads Use in OpenSim ...

Wed Apr 9 16:03:49 UTC 2008

Hi Stefan,

Well, I'm now testing SVN.4111 and it seems to work better ...  
Sometimes the Sim freeze, but most often in Standalone mode.

For now, I can run OpenSim, with acceptable response time in 4x4  
Regions.

And I had an Idea the past night :)

I think the component that use too many CPU is the one that deal with  
port 9000 ( mean something in OpenSim.exe ).

Here is what I'm thinking that :

As I mention in Mantis #909, I'm running OpenSim in Grid mode, 4x4  
Regions, BUT, I have created 6 Virtual Servers with Xen.

Linux Debian 4.0r3 Etch, Mono 1.9 /  Xen 3.1.0.

Here is the Topology  :

Dom0 ( 256Mo ) <-- Main Host ( Nothing on it except xen ),
DomU ( osg200 / 256MB Ram ) <-- Apache + MySQL ( Maybe Squid in the  
future ),
DomU ( osg201 / 256MB Ram ) <-- OpenSim "U+G+A+I", ( Will update it to  
512MB Ram )
DomU ( osg203 / 512MB Ram ) <-- OpenSim "S" ( Region Server, 4  
Regions ),
DomU ( osg204 / 512MB Ram ) <-- OpenSim "S" ( Region Server, 4  
Regions ),
DomU ( osg205 / 512MB Ram ) <-- OpenSim "S" ( Region Server, 4  
Regions ),
DomU ( osg206 / 512MB Ram ) <-- OpenSim "S" ( Region Server, 4  
Regions ),

The startup order is : osg200 > osg201 ( UGAI ) > osg203 (S) >  
osg204 ...

While monitoring my firewall logs, I found that even if my avatar is  
located in a region that belongs to OSG204( for example ) ... There  
was Network Trafic to port 9000 ( OSG203 -- The first Region server I  
started ).
And, while monitoring RAM/CPU Usage on my Virtual Servers, I have  
noticed that OSG203 is in "High CPU usage" state ( much more that  
OSG204, 205 or 206 )

Of course I have to confirm all those points and drop you some  
metrics. And I have some more tests to prove that. But it could be a  
good start point for investigation.

I'll make tests tonight and post the results there.

Regards,

Ursula.

(( Ouch, my english turns bad :D Sorry. ))

Le 9 avr. 08 à 17:48, Stefan Andersson a écrit :

> What's the current status on the thread issues? Are we looking into  
> it? Have we identified consumers/culprits?
>
> Best,
> /Stefan
>
>
>
> > From: ursula.matova at klintcentral.net
> > To: opensim-dev at lists.berlios.de
> > Date: Sun, 17 Feb 2008 11:09:27 +0100
> > Subject: [Opensim-dev] Question about Threads Use in OpenSim ...
> >
> > Hi all,
> >
> > First, please be indulgent about my poor english :) You all know how
> > french people are bad with foreign languages ...
> > Thanks in advance.
> >
> > Well, I'm running OpenSim in StandAlone mode, 3x3 Regions ( as Grid
> > mode is so difficult to configure behind a firewall ) ...
> > Using a home made "Linux From Scratch" box with Mono 1.2.6 ( daily
> > snapshot ) ...
> > The computer is an Athlon64X2 4400+ with 4GB Ram ... ( is it large
> > enough ? )
> >
> > In the past ( before SVN.3335 or something ) when running OpenSim,
> > just after the simulator goes Up, the OpenSim.exe process use around
> > 96 threads and everything works fine,
> > But, now, I saw that this number of threads reach 118 :(
> > As I posted in the past in Mantis that Mono under Linux is really  
> bad
> > ( performances & coredump ) when you reach the limit of 170  
> threads ...
> >
> > When I connect 1 user to the sim : Thread count is now reaching :  
> 157
> > When I connect a 2nd user to the sim : Thread count reach : 200
> > ( in that case : 200 threads used, the sim doesn't crash like in the
> > past but I find everything slow ... and my CPU is now 100% use / 7%
> > Ram used )
> >
> > Then, that mean, each time a user is connecting to the Sim, it use
> > about 40 threads ...
> > So, if I like to connect 20 users, I need around 40x20 threads = 800
> > threads ...
> > And I'm not sure at all that Mono could manage that :(
> >
> > What's you're feeling on that point ?
> >
> > So, my question is : why not forking a new "OpenSim.exe" process for
> > each new connected user ?
> > Of course it's mostly for the standalone mode ( but the problem is a
> > bit the same in Grid Mode ) ...
> >
> > Maybe it's a simple/stupid idea from me, because I haven't enough
> > development skills to help all the people working hard to bring up
> > this marvelous simulator.
> >
> > Please, just let me know your position about it.
> >
> > Thanks a lot guys for all your dev,
> >
> > Regards,
> >
> > Ursula Matova
> > ( Of course this is my S/L Avatar Name :) )
> >
> >
> > _______________________________________________
> > Opensim-dev mailing list
> > Opensim-dev at lists.berlios.de
> > https://lists.berlios.de/mailman/listinfo/opensim-dev
>
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