MapServer Performance Tips

[Paul Ramsey]

Tim,

You're getting some good advice on mapfile layout, which can be 
summarized as "don't draw features that you cannot see, or don't need to 
see". So don't draw 500K roads into a 1000x1000 image, because each road 
will barely take up a pixel, it's a waste of CPU time.

Since you're using Oracle, if you want performance, you *MUST* do the 
following:

* Run Mapserver as a fastcgi process
* Use CLOSE_CONNECTION=DEFER as a processing instruction at the end of 
your Oracle layers

Otherwise the connection overhead will kill you.

Also watch out for using "init=epsg:xxxx" PROJECTION strings, as 
Mapserver opens and reads the epsg file for each one of them.  Better to 
just spell out the whole projection.  This can be a huge win on maps 
with piles of layers.

Paul

Timothy J Nolte wrote:
> Now that I finally have MapServer talking to our Oracle database my next big
> issue is performance. Does anyone have any tips on MapServer performance?
> 
> We're running MapServer on:
> 	Sun e450
> 	4 x 400MHz Sparc II Processors
> 	4GB ram
> 
> I have around 42GB of map data I'm trying to serve up. I'm not seeing the
> greatest performance. Are there any key things I need to remember with the
> setup of my Shapefile data? Are there certain things I should do with my
> .map file to help performance? Anyone using the DM Solutions US Streets
> data, any issues with performance there? What kind of hardware are others
> running on? Thanks.


-- 

   Paul Ramsey
   Refractions Research
   http://www.refractions.net
   pramsey at refractions.net
   Phone: 250-383-3022
   Cell: 250-885-0632