[mapserver-users] How to make MapServer WMS super fast?

[pcreso at pcreso.com]

Hi,

Some general comments, not juat related to mapserver setup...

I think your peformance is likely to be more raster limited than vector, but apart from fast-cgi you might try using jpg's or png's with world files instead of geotiffs. Much smaller image file sizes (but two files to access) so less disk access time to retrieve them, but generally more cpu overhead to process them. I can't say which will result in overall faster performance, it depends on whether you are more I/O or cpu bound. 

Also, if you have large shapefiles, and are generally just rendering a small subset of them, you may find managing yor vector data in Postgis will be faster. Shapefiles seem to be faster when you want to plot most of or the whole dataset, but if you want to select attribute or spatial based subsets, they can be significantly faster on a well indexed Postgis table.

Also, depending on your system, you can abstract your Postgis database to a separate physical database server, whereas - barring network mounts - your shapefiles need to reside on the same server as your imagery (although having your rasters & shapefiles on different physical disks & filesystems on a single server can improve I/O performance as they can be read concurrently - assuming your SCSI controllers are up to the task).


Also, I have found Linux to be faster than Windows, quite significantly in some cases, although some opinions here differ :-) With Linux I find you can choose & tune your filesystem better, and 64bit Linux makes more effective use of large memory configurations (like 8-64Mb if you can get it). Adding memory to heavily loaded servers is one of the first ways to improve overall performance, if your OS can use it effectively. 


Cheers,

  Brent Wood