MapServer performance

[Travis Kirstine]

Antti,
I will think you will find that if you create a mapserver spatial index
files (.qix) for all shapefiles using the shptree utility performance will
improve.  Also  if you have large shp files you may consider 1. chopping up
the files into smaller tiles and referencing the files with a tiles with a
index (use tile4ms) and/or 2. extracting classes from the shapefile based on
attributes eg separating a roads layer to major, highways, local etc...
Increasing performance of raster data has been written about quite a bit on
the list but the basic idea is to create a series of rasters of varying
resolutions and sizes that will be turned on and off using the MINSCALE
MAXSCALE in you mapfile.  For example if you have high resolution imagery
(1m pixel resolution) you could create a reduced resolution tile or merge
together a group of tiles with a resolution of 10m that would be viewed when
the user is zoomed out.  You may also consider chopping some of your large
files to smaller tiles.  The rasters should have overviews (created with
gdaladdo) have internal tiles and referenced with a tile index (created with
gdaltindex).
See:
http://mapserver.gis.umn.edu/docs/howto/raster_data/#raster-display-performa
nce-tips

Travis

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]On
Behalf Of antti siukola
Sent: Friday, March 23, 2007 5:11 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] MapServer performance


Hi!

Thanks for the reply!

My tiff's are from 15M to 10G tiff tiles (about 500M each tile) and
depending on the map theres the one 15M tiff or from 2 to 3 of the
500M tiles displayed (I have couple of map apps running on the
server). It doesn't seem to matter how big the tiff's are since the
performance is the quite the same. I also have the .shx files for my
shape's.

The server doesn't get very much hit's since it's not an open for
public application. I believe the average usage is about 1-10 users at
the same time.

Hope this helps!

Antti S

On 3/21/07, Romolo Manfredini <romoloman at hotmail.com> wrote:
> From: "antti siukola" :
>
> > Oh, yes. I'm on linux with mapserver 4.8.4 and php mapscript. The
> > server is quite new and powerful with dual xeon and 1024M of memory.
> > Data sources are mostly SHP-files and few TABs for vector data and
> > labels. The actual maps are .tif images. I'm using tiled tiff's and
> > low-res images on upper scales.
> >
>
> SHP and tiff files are typically bad beast to manage expecially if they
are
> big shape and big tiff, also dependig on file system type you may have
some
> performance issues related to locking and caching. (1 GB ram with large
> files is not so much)
> Also, do you have spatial index on your files (.shx) ?
> Spatial index improve performances a lot.
> May you tell me the size of your files and how many of them are involved
in
> a single map ?
>
> Best Regards,
> Romolo
>
>