[mapserver-users] Using Fast CGI with MapServer to alleviate poor performance

[John Westwood]

Hi Paul and other MapServer Gurus,

I have discovered a huge speed increase by using OpenLayers.MapServer (native) layers instead of OpenLayers.WMS layers. It is about ten times faster, I do not exaggerate. Why is WMS so slow? I have read that MapServer is a fast WMS server, have I done something wrong for it not to be?

What do you think could be the problem?

I will give it some thought tomorrow.

John




>>> "Paul Ramsey" <pramsey at cleverelephant.ca> 17/09/08 5:15 PM >>>
John,

The idea that CGI is naturally a much slower situation than a
long-running process is a bit of a red herring in the case of
Mapserver, and I say that as someone who is anal retentive about these
things.  Unless your Mapserver installation has some naturally latent
components (database connections, primarily) you'll find that moving
from CGI to FastCGI is worth about 15ms per request.

On Wed, Sep 17, 2008 at 8:40 AM, John Westwood <John.Westwood at port.ac.uk> wrote:

> The reason I am trying to get MapServer to work with fast_cgi is because I am experiencing poor performance with OpenLayers. I believe that OpenLayers starts a new MapServer instance for each tile request, thus causing an unnecessary overhead. Am I correct?

Yes and no. If you are experiencing noticeably poor performance (you
can actually *see* it being slow) the only place that the CGI overhead
could be the cause is if you're connecting to Oracle or SDE for some
of your layers. If that's not the case, look elsewhere first, the very
small gains you will receive from moving to FastCGI will not change
your underlying problem.

Paul