Very slow WMS connection through GIS application

[Rahkonen Jukka]

Hi,

Mapserver is not going through _every_ image included in tileindex, but it does do that for all images falling inside the bounding box of your request. But if you show the whole layer it means the same thing. WMS is not caching anything so for every new request everything is done from the beginning.

For sure it is not the most effective way to go through some 70 big image files just for getting a resulting WMS image with a size of 600 by 800 pixel or something. Maybe you could start with some low resolution layer first and throttle the high resolution layers by using MINSCAlE/MAXSCALE? Or do you mean that your layers act slow even when zoomed so close that rendering from just couple of image files is enough?

Regards,

-Jukka Rahkonen-


-----Original Message-----
From: UMN MapServer Users List on behalf of Ryan Ollerenshaw
Sent: Thu 6.7.2006 18:08
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] Very slow WMS connection through GIS application
 
The connection to my WMS server through a GIS application such as uDig or ArcGIS
is painfully slow, Does anyone know what could be causing this?  My dataset is
rather large about 70 high resolution tiles, it seems like whenever I do a pan
or a zoom the GIS application is reloading every tile, is there a way to keep
this from happening?

Thank you and here is my map file incase it may provide some clues as to what I
have done wrong:

NAME WMSDEMO
STATUS ON
SIZE 1000 600
EXTENT 0 -90 360 90
#UNITS METERS
SHAPEPATH "../data"
IMAGECOLOR 255 255 255

WEB
  TEMPLATE test_template.html
  IMAGEPATH "/tmp/ms_tmp/"
  IMAGEURL "/ms_tmp/"
  METADATA
    WMS_TITLE   "WMS_Mars_mapserver"
    WMS_ACCESSCONSTRAINTS "none"
    #WMS_ONLINERESOURCE "http://neuron/cgi-bin/mapserv?map=display.map&"
    WMS_SRS     "EPSG:4326" #"AUTO:42003"
  END
END

PROJECTION
  "init=epsg:4326"
END


LAYER
  NAME "themis"
  STATUS ON
  TILEINDEX "thm_dir.shp"
  TILEITEM "location"
  TYPE RASTER
  DUMP TRUE
  METADATA
    WMS_TITLE "THEMIS_Data"
  END
END
LAYER
  NAME "moc"
  STATUS ON
  TILEINDEX "moc_256.shp"
  TILEITEM "location"
  TYPE RASTER
  METADATA
    WMS_TITLE "MOC_Data"
  END
END

LAYER
  NAME "mola"
  STATUS ON
  TILEINDEX "mola_color.shp"
  TILEITEM "location"
  TYPE RASTER
  METADATA
    WMS_TITLE "MOLA_Data"
  END
END



END # of map file