[mapserver-users] High CPU

Even Rouault even.rouault at mines-paris.org
Sun Sep 7 05:30:20 EDT 2008


I would say that a CPU load at 100% when responding to WMS requests is 
perfectly normal and expected. It shows that the process is not stuck at 
waiting for I/O to be completed.

Maybe you could complain that mapserver is doing its job too slowly, but I 
don't understand why a 100% CPU load is a problem. If your server must handle 
several requests at the same time, the OS will share the CPU resource between 
all requests. If you really don't want to reach 100%, there are probably ways 
of instructing your OS to schedule mapserver a bit less agressively.

Increasing RAM would unlikely change that (it would be usefull only if you saw 
low CPU usage because of swap trashing for example). Increasing CPU speed 
neither. It would just run at 100% for a shorter time.

Le Sunday 07 September 2008 10:20:08 Steve White, vous avez écrit :
> The problem is that CPU shoots to 100% while tiles are being generated from
> a remote WMS call.
>
> The shp2img dump was taken directly on the server but the problem occurs
> when I send remote WMS requests to the server.
>
> I'm starting to think that 640MB RAM isn't enough and I should probably
> bump it up to 1GB.
>
>
> -----Original Message-----
> From: Paul Ramsey [mailto:pramsey at cleverelephant.ca]
> Sent: 07 September 2008 06:07
> To: Steve White
> Cc: mapserver-users at lists.osgeo.org
> Subject: Re: [mapserver-users] High CPU
>
> It took 0.3s to run to completion, what's the problem precisely?
>
> P.
>
> On Sat, Sep 6, 2008 at 1:35 PM, Steve White
>
> <steve at online-archaeology.co.uk> wrote:
> > Thanks Jeff -
> >
> >
> >
> > -          I upgraded to MS4w 2.2.9
> >
> > -          I ran shptree.exe and produced the index file
> >
> > -          My results of shp2img.exe are below
> >
> > -          I don't think any projections-on-the-fly are occurring
> >
> >
> >
> > Shp2img dump:
> >
> >
> >
> > msDrawMap(): Layer 0 (OA), 0.015s
> >
> > msDrawMap(): Drawing Label Cache, 0.000s
> >
> > msDrawMap() total time: 0.015s
> >
> > SaveImage() total time: 0.297s
> >
> > msFreeMap(): freeing map at 0144B498.
> >
> >
> >
> > I'm still getting very high CPU usage with just one active session, so
> > there's no way I can go into production till this is resolved.
> >
> >
> >
> > Any other things I can look at?
> >
> >
> >
> > Cheers,
> >
> >
> >
> > Steve
> >
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> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
>
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