tileindexed layer crashing...

[Ed McNierney]

Jeff -
 
Thanks for the confirmation.  And thank you for adding that very
valuable information you didn't mention the first time <g>.  If your map
worked fine the first time, ignore my entire previous email - your index
and shapefiles seem to be working fine.  If you have no MINSCALE or
MAXSCALE settings on your layers, is your attempt to view "the entire
area" really a map request to draw every single road in the United
States?  You should not be surprised if that effort is a little
overwhelming for your server.  If you can scroll around at your original
zoom level and see streets correctly, then your setup should be fine and
you need to move on to wisely classifying and selecting your data so
each map draw uses a reasonable and appropriate subset of your data.
 
You're misunderstanding my comments about your TILEINDEX.  Each of your
individual TIGER files is a shapefile.  A TILEINDEX file is ANOTHER
shapefile made up of rectangular polygons, each describing the extent of
one of your TIGER files.  The index is used to quickly determine which
source TIGER files overlap the requested output map area at all - those
are the only ones that need to be opened to try to draw the final map.

        - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396
ed at topozone.com

________________________________

From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Jeff Portwine
Sent: Friday, March 18, 2005 11:25 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: Re: [UMN_MAPSERVER-USERS] tileindexed layer crashing...


First, some nit-picking.  I presume you did something first to create a
"data_dir.in" file, right?  And there's a space between xargs and "-n",
correct?  The latter shouldn't make much difference.
 
Yea, there is a space between xargs and -n, i mistyped in the email.
The data_dir.in file was just a listing of all the tiger data files,
created with  "find /homedir/tiger -name "*.shp" > data_dir.in".
 
Does your tiger-roads shapefile look OK?  Do the filesizes look
plausible?  Can you view it in a GIS application (it's just a regular
shapefile)?
 
The file sizes looked reasonable to me... but I don't really know how
big they should be.   I don't have any other GIS applications atm, but I
could try to download something to try to view the shapefile.    

        As a diagnostic step, I'd suggest changing TILEINDEX to DATA in
your LAYER definition, and the TYPE to POLYGON.  The tile index is a
polygon shapefile with a bunch of rectangles, each describing the
bounding box of one input file.  Use this technique to see if the tile
index file itself looks reasonable.  If it does, then your problem's
likely to be with your TIGER data - otherwise, the TILEINDEX file needs
fixing.

 I am not entirely sure what you mean here ... how to diagnose the tile
index.   I actually thought I had to use TILEINDEX to view a shapefile
created with this method.    If I can just use it like any other
shapefile I probably don't even need to tile it... i'm not trying to do
roads for the entire country or anything, though in theory the tiling is
probably better.

 

When I first added the layer, my map was in a zoomed in state and it
seemed ok... it was when I hit the "recenter" button and it tried to go
back to view the entire area that it blew up.   Perhaps tiling isn't so
good for that situation since i'm looking at the whole area anyway...

 

-Jeff