[ka-Map-users] Mapserver Throtteling
azza at lisasoft.com
Mon Nov 13 20:18:23 EST 2006
I will most likely do this myself and attempt to contribute back, but
first with the explaination.
It is nice to see that in KA-Map that a Lock file is written to prevent
simultaneous identical* tile requests (*or same meta tile). The
principal of a simple lock file could also be used to throttle
concurrent non-unique tile requests. I have experienced problems
(particularly cascading to another server) where flooding the server
trashes the cache and the client experience because of excessive load.
Throttling the mapserver access to say X many concurrent requests would
ensure quality of service to at least some users and would protect the
cache integrity. Users that find themselves on an overloaded server
could be given a tile with a polite message (and the browser told not to
cache the image).
I also modified the "tile.php" to be a "readonly" server that provides a
polite message... something that was very easy. This is much the same as
above (without the throttle).
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