[mapserver-users] Slow mapfile
Steven M. Ottens
steven at minst.net
Fri Nov 30 02:16:58 PST 2012
Hi all,
I'm having troubles generating tiles with mapserver, they take up to
half an hour per tile (256x256pixels).
The data is stored as a series of 32bit float GeoTIFFs, internally tiled
with gdal and provided in four different levels (5meter, 25meter,
100meter and overview) as a series of files in separate directories
which are indexed with gdaltindex.
The data is a detailed height model of the Netherlands with a vertical
resolution of 1cm - this way the Netherlands doesn't look so flat ;). I
need to encode this data into a specially crafted PNG to be able to do
dynamic classification in the browser. This means that for the range
-12m to 350m I want each centimetre as a different colour. I end up with
36200 classes and a mapserver which is working for half an hour on 100%
on a 2.6GHZ Quad-Xeon server with 8GB RAM, Ubuntu 12.04, gdal 1.9.2 and
mapserver 6.2.0.
The tiles are created by TileCache 2.11 and a tileseed.py run on the
same server and the data is in the same projection as the tiles.
I'm aware that 36200 classes are a lot, but I do need the 36200 values
encoded in my PNG-tiles. Currently I use an include to include the
classification for the different layers, since the classification alone
is almost 3MB.
Any suggestions on how to improve the render-speed, either in data
preparation, the mapfile or a different approach all together?
Regards,
Steven
Snippet of the included class.map:
CLASSITEM "[pixel]"
CLASS EXPRESSION ( [pixel] < -11.99 ) COLOR 0 0 0 END
CLASS EXPRESSION ( [pixel] >= -11.99 AND [pixel] < -11.98 )
COLOR 0 0 1 END
###36000+ more classes###
CLASS EXPRESSION ( [pixel] >= 349.99 AND [pixel] < 350 ) COLOR
0 141 103 END
CLASS EXPRESSION ( [pixel] >= 350 ) COLOR 0 141 104 END
The main mapfile:
MAP
EXTENT 10000 305000 280000 619000
UNITS METERS
NAME "AHN hoogtes"
SHAPEPATH "/var/data/hoogte/nederland"
PROJECTION
"init=epsg:28992"
END
LEGEND
IMAGECOLOR 255 255 255
KEYSIZE 18 12
KEYSPACING 5 5
LABEL
ANTIALIAS TRUE
SIZE 9
TYPE TRUETYPE
FONT "Arial"
BUFFER 0
COLOR 0 0 89
FORCE FALSE
MINDISTANCE -1
MINFEATURESIZE -1
OFFSET 0 0
PARTIALS TRUE
END
POSITION UR
STATUS ON
TRANSPARENT TRUE
END #legend
QUERYMAP
COLOR 255 0 0
SIZE -1 -1
STATUS OFF
STYLE HILITE
END #querymap
DEBUG 0
WEB
# Path to the temporary directory fro writing temporary files and
images.
# Must be writable by the user the web server is running as.
# Must end with a / or \ depending on your platform.
IMAGEPATH "/tmp"
# Base URL for IMAGEPATH. This is the URL that will take the web
browser to
# IMAGEPATH to get the images.
IMAGEURL "/tmp/"
MAXSCALE 30000000
MINSCALE 1000
METADATA
WMS_TITLE "Algemeen Hoogtebestand Nederland"
WMS_ABSTRACT "Algemeen Hoogtebestand Nederland"
WMS_ONLINERESOURCE
"http://localhost/cgi-bin/mapserv?map=maps/hoogte.map"
WMS_SRS "EPSG:28992"
WMS_ENABLE_REQUEST "*"
END
END # web
OUTPUTFORMAT
NAME png
DRIVER "GD/PNG"
MIMETYPE "image/png"
IMAGEMODE PC256
EXTENSION "png"
END # outputformat
LAYER
GROUP "ahn2"
NAME "ahn2_max"
METADATA
WMS_TITLE "Hoogte Max Res"
WMS_ABSTRACT "Hoogte Max Res"
WMS_NAME "Hoogte Max Res"
WMS_SRS "EPSG:28992"
WFS_TITLE "Hoogte Max Res"
WMS_GROUP_TITLE "hoogte"
END
PROJECTION
"init=epsg:28992"
END
DATA "ahn2-2012/overview.tif"
STATUS ON
DEBUG 0
TEMPLATE "blank.html"
TYPE RASTER
UNITS METERS
PROCESSING "SCALE=-12,350"
PROCESSING "SCALE_BUCKETS=36200"
MINSCALE 500000
MAXSCALE 30000000
INCLUDE "class.map"
END # layer ahn2
LAYER
GROUP "ahn2"
NAME "ahn2_100m"
METADATA
WMS_TITLE "Hoogte 100m"
WMS_ABSTRACT "Hoogte 100m"
WMS_NAME "Hoogte 100m"
WMS_SRS "EPSG:28992"
WFS_TITLE "Hoogte 100m"
gml_include_items "value_0"
gml_value_0_alias "hoogte"
WMS_GROUP_TITLE "hoogte"
"wcs_label" "Hoogte 100m" ### required
"wcs_rangeset_name" "Hoogte 100m (rangeset name)"
### required to support DescribeCoverage request
"wcs_rangeset_label" "Hoogte 100m (rangeset label)"
### required to support DescribeCoverage request
END
PROJECTION
"init=epsg:28992"
END
TILEINDEX iahn2_raster100_index
TILEITEM "location"
STATUS ON
DEBUG 0
TEMPLATE "blank.html"
TYPE RASTER
UNITS METERS
PROCESSING "SCALE=-12,350"
PROCESSING "SCALE_BUCKETS=36200"
MINSCALE 150000
MAXSCALE 500000
INCLUDE "class.map"
END # layer ahn2
LAYER
GROUP "ahn2"
NAME "ahn2_25m"
METADATA
WMS_TITLE "Hoogte 25m"
WMS_ABSTRACT "Hoogte 25m"
WMS_NAME "Hoogte 25m"
WMS_SRS "EPSG:28992"
WFS_TITLE "Hoogte 25m"
gml_include_items "value_0"
gml_value_0_alias "hoogte"
WMS_GROUP_TITLE "hoogte"
"wcs_label" "Hoogte 25m" ### required
"wcs_rangeset_name" "Hoogte 25m (rangeset name)"
### required to support DescribeCoverage request
"wcs_rangeset_label" "Hoogte 25m (rangeset label)"
### required to support DescribeCoverage request
END
PROJECTION
"init=epsg:28992"
END
TILEINDEX iahn2_raster25_index
TILEITEM "location"
STATUS ON
DEBUG 0
TEMPLATE "blank.html"
TYPE RASTER
UNITS METERS
PROCESSING "SCALE=-12,350"
PROCESSING "SCALE_BUCKETS=36200"
MINSCALE 30000
MAXSCALE 150000
INCLUDE "class.map"
END # layer ahn2
LAYER
GROUP "ahn2"
NAME "ahn2_5m"
METADATA
WMS_TITLE "Hoogte 5m"
WMS_GROUP_TITLE "hoogte"
WMS_NAME "Hoogte 5m"
WMS_ABSTRACT "Hoogte 5m"
WMS_SRS "EPSG:28992"
WFS_TITLE "Hoogte 5m"
gml_include_items "value_0"
gml_value_0_alias "hoogte"
"ows_srs" "EPSG:28992"
END
PROJECTION
"init=epsg:28992"
END
TILEINDEX iahn2_raster5_index
TILEITEM "Location"
STATUS ON
DEBUG 0
TEMPLATE "blank.html"
TYPE RASTER
UNITS METERS
PROCESSING "SCALE=-12,350"
PROCESSING "SCALE_BUCKETS=36200"
MINSCALE 1000
MAXSCALE 30000
INCLUDE "class.map"
END # layer ahn2
END #map
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