[OpenLayers-Users] Occasionally getting hundreds of requests in a short time

[Scott Lewis]

I'm working on an application using OpenLayers that has a Tilecache/WMS
backend to serve the map images.  For the most part, it runs pretty
smoothly without too much load on the mapserver.  However, every once in
awhile, maybe once a week or so, something happens where several hundred
requests are sent to the backend in a very short amount of time, causing
the server to crash or grind to a halt because of it.

While I'm sure this is due, in part, to some action by a user, I'm not
quite sure what it could be.  Even though I'm using Tilecache, the
requests that are eventually causing this are going to the WMS server
itself, indicating that the cache does not currently have the requested
images.

I'm not sure if this is a "problem" with OpenLayers itself, but it is
becoming a problem for our server.  Has anyone experienced this in their
applications?  If so, what may be the cause?  About the only thing I can
think of is maybe a user using the scroll wheel to rapidly zoom in (and
out?) of an area that hasn't been cached, or perhaps many users trying
to hit the cache at nearly the same time (which could be from some kind
of lab or class or something).

Thanks in advance,

Scott Lewis
National Snow and Ice Data Center
Boulder, CO, USA