An internet user visits a web site and requests to see imagery from a
specified one of a plurality of video cameras. At a system associated
with the web site, a load distribution server assigns the user's request
to one of a plurality of image servers. The assigned image server first
checks its local image cache to see whether a recent image from the
specified camera is stored there. If so, the image from that local image
cache is sent to the user. If the local image cache does not have a
recent image from the requested camera, the assigned image server then
checks its local request cache to see whether an earlier process has
recently requested the same imagery. If so, then the assigned image
server simply waits for the earlier process to compete instead of
initiating its own new image retrieval request. If no earlier process has
recently requested the same imagery, the assigned image server issues its
own image retrieval request. Information in image and the request caches
of each image server is replicated across all the image servers.