[mapserver-users] Re: performance of our installation is way off

[Brian Hill]

I figured this out.  It was misuse of tile4ms.  At 
http://mapserver.gis.umn.edu/utils.html, the documentation for tile4ms 
suggests the following:

    find . -name "*.shp" -print > metafile.txt
    tile4ms metafile.txt tileindex

For the tiger dataset, there are 10 or so .shp files for each fips code. 
 Each of them has essentially the same extent, and so the index has 10 
or so very similar entries for each fips code.

I re-ran the find as

    find . -name "cty.shp" -print > metafile.txt
    tile4ms metafile.txt tileindex

and edited all the /cty out of the locations using ArcView.  The 
resulting index has 58 entries instead of 799. I don't know what I am 
doing very well, but the proof is in the pudding:

http://skip.nextbus.com/cgi-bin/imap/mapper?wid=.03&ht=.03&lat=37&lon=-122 
<http://skip.nextbus.com/cgi-bin/imap/mapper?wid=.03&ht=.03&lat=37&lon=-122> 


now only takes a couple of seconds.  Yahoo!  --Brian

Brian Hill wrote:

> It is taking 15 to 20 seconds to render a map on a fast Linux/Intel 
> system with all binaries and data local, which is off by a factor of 5 
> or more from what I was expecting.  For example, hit:
>
> http://skip.nextbus.com/cgi-bin/imap/mapper?wid=.03&ht=.03&lat=37&lon=-122 
>
>
> I used tile4ms from a 3.5 nightly distribution to index all the Tiger 
> shape file data for California. Otherwise, the system is a 3.3.012 
> system.  The .map file has been pared pretty hard.
>
> Does anyone know of performance trouble-shooting techniques for the 
> mapserver system or common build/app/data problems that can severely 
> impact performance?
>
> In an earlier post, data thinning, pre-projection and spatial indexes 
> were mentioned, but these are just buzzwords to me.  I haven't found 
> directions for actually applying these techniques in the documentation.
>
> Thanks for any tips on how to narrow the problem down or fix it.
>
> Brian Hill
> Sr. Software Engineer
> NextBus Information Systems
> (510)420-3122
>
>