Patent ID: 7222344

Claim:
A method of maintaining session data in a server system serving a network, said server system including at least one network server and at least one database server, said method comprising the steps of: (1) storing in a memory that is local to said at least one network server, session data for a plurality of sessions serviced by said at least one network server; (2) storing in a database that is local to said at least one database server, copies of said session data for a plurality of sessions serviced by said at least one network server; (3) performing contemporaneous time out testing of particular session data stored in said memory local to said at least one network server for one of said plurality of sessions every time a request is received for said particular session data prior to utilizing said particular session data, and not invalidating a copy of said particular session data in said database even if said contemporaneous testing has indicated that the corresponding session has timed out; (4) performing an invalidation procedure on all said copies of said session data in said database when a load on said at least one database server is below a threshold and at a particular time that is independent of when said contemporaneous testing is performed, wherein said invalidation procedure comprises setting a one-bit flag to indicate that said session data is invalid; wherein said invalidation procedure comprises the steps of: (4.1) for each copy of said session data in said database, determining if said session has timed out; (4.2) for each session that has timed out, invalidating the corresponding copy of session data in said database; and (5) periodically determining a load on said database; and wherein said particular time is a function of said determined load and a predetermined interval.