Patent attributes
A CDN that employs a load balancer that uses probabilistic filters to estimate sizes of requested data objects and that balances incoming request loads according to the estimated sizes is provided herein. For example, the load balancer stores probabilistic filters. Each probabilistic filter is associated with a size range. When the CDN receives a data object request, the load balancer generates a cache key and tests whether the cache key is a member of any probabilistic filter. If the cache key is a member of a probabilistic filter, then the load balancer estimates a size of the requested data object based on the probabilistic filter of which the cache key is a member. The load balancer then uses the estimated size to estimate the added load on one or more cache servers. Based on the estimated added load, the load balancer selects a cache server to handle the request.