MapGuide RFC 64 - Enabling strict exception handling for tile generation
This page contains an change request (RFC) for the MapGuide Open Source project. More MapGuide RFCs can be found on the RFCs page.
|RFC Template Version||(1.0)|
|Last Modified||(UV Wildner) Timestamp|
|Implementation Status||(discussion needed)|
|Assigned PSC guide(s)||(when determined)|
|Voting History||(vote date)|
Currently an exception thrown during the stylization code for a tile is caught and ignored. This can lead to partially incomplete tiles which are hard to detect as no error information is passed via the API. Even worse the tile is kept in the tilecache!
Originally, the mapguide server has been designed as an interactive map generation system. For the important use case of rendering tiles and filling the tile cache incomplete tiles are undesirable. in particular keeping the faulty tile in the cache seems the wrong way to go.
A switch in serverconfig.ini should be introduced which can change this behaviour on demand. e.g. HandleRenderingErrors = STRICT
which leaves us room for additional ways to deal with this:
render a tile with an error message could be
HandleRenderingErrors = SHOW
HandleRenderingErrors = IGNORE
HandleRenderingErrors = DEFAULT
and ommitting the parameter would change nothing
However I think letting the tile into the cache should be generally prohibited in an exception situation.
Render tiles on a low memory virtual machine which causes memory errors and compare TileCache with different settings
Does anyone wants to have faulty tiles in the tile cache?