Patent ID: 7461206

Claim:
A computer-readable medium whose contents cause a computing system to perform a method for managing a cache, the method comprising: receiving a request for an object; if the cache does not contain a cached version of the object: obtaining a current version of the object from a source associated with the object; storing the obtained current version of the object in the cache; attributing a minimum lifetime and a maximum lifetime to the current version of the object based upon the time at which the current version of the object was stored in the cache; using the current version of the object to respond to the received request; if the cache contains a cached version of the object: if a minimum lifetime attributed to the cached version of the object has not expired, using the cached version of the object to respond to the received request; if the minimum lifetime attributed to the cached version of the object has expired, but a maximum lifetime attributed to the cached version of the object has not expired: determining a random or pseudorandom number within a range; if the determined number exceeds a probability threshold determined with respect to the range, using the cached version of the object to respond to the received request; if the maximum lifetime attributed to the cached version of the object has expired, or if the determined number does not exceed the probability threshold: obtaining a current version of the object from the source associated with the object; storing the current version of the object in the cache; attributing a minimum lifetime and a maximum lifetime to the current version of the object based upon the time at which the current version of the object was stored in the cache; and using the current version of the object to respond to the received request.