On Tue, Nov 06, 2007 at 05:52:22PM +0100, Jacolin Yves wrote: > Why don't you use > "wms_exceptions_format" "application/vnd.ogc.se_inimage" ?
This is because I have a webcache in front of mapserver, which will cache requests for about twelve hours, and I need a way to tell an errormessage apart from a successful response. The way it is now, blank images sneaks into the cache occasionally, and this is what I'm trying to avoid. I need the cache, because we regularly get over 300 requests per second (highest peak I've seen so far is 604 request in a single second), and our servers can't handle this load without caching. Over the last nine and a half days, we've had almost 110 million wms requests to our cache, and only 4 million went to the backend. So basically - I desperately need the cache, but it's extremely important that it doesn't cache blank images or other error messages embedded in an image, which is why I want mapserver to return an application/vnd.ogc.se_xml error whenever any sort of error happens. > Le Tuesday 06 November 2007 17:35:17 Trond Michelsen, vous avez écrit : >> Hi. >> >> In my mapfile, I have several layers with connectiontype WMS. Once in >> a while, the WMS-servers that deliver these layers will fail, usually >> due to high load, and return an application/vnd.ogc.se_xml >> exception. In these cases, I'd like mapserver to return an exception >> as well, but instead, mapserver will just log the error message in >> MS_ERRORFILE, and continue drawing the rest of the layers. If there >> are no more layers, it will result in a blank image. >> >> (BTW: I've also noticed the same behaviour if the remote wms-server >> answers with an internal server error) >> >> Here's the layer definition that I use for testing. exception.cgi will >> always return a dummy XML exception. >> >> LAYER >> NAME "exception" >> TYPE RASTER >> STATUS ON >> CONNECTION "http://wms1.oslo.dnmi.no/cgi-bin/exception.cgi"; >> CONNECTIONTYPE WMS >> OFFSITE 255 255 254 >> METADATA >> "wms_srs" "EPSG:4326" >> "wms_name" "exception" >> "wms_server_version" "1.1.1" >> "wms_formatlist" "image/png" >> "wms_format" "image/png" >> "wms_exceptions_format" "application/vnd.ogc.se_xml" >> END #metadata >> END #layer >> >> Is there something I can do to force mapserver to fail, and return an >> exception if it fails to draw any of the wms-layers? >> >> I'm using mapserver 4.10 >> >> $ cgi-bin/mapserv -v >> MapServer version 4.10.0 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP >> OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER >> SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT >> SUPPORTS=WCS_SERVER SUPPORTS=THREADS SUPPORTS=GEOS INPUT=EPPL7 >> INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE DEBUG=MSDEBUG -- Trond Michelsen
