Abstract:
An object caching system (100) serving an Intranet (102) includes a cache name server (106) and a plurality of web cache servers (108A-108D). Each of the plurality of web cache servers (108A-108D) couples to an Intranet (104) and to the Internet (102) and stores a respective plurality of Internet objects that have been previously retrieved from the Internet (102). The cache name server (106) couples to the Intranet (104), receives a request for an Internet object from a web client (110A) coupled to the Intranet (104), and directs the web client (110A) to a serving web cache server (108A) of the plurality of web cache servers (108A-108D) based upon the request. If the serving web cache server (108A) possesses a copy of the Internet object, it returns a copy of the Internet object to the web client (110A). However, if the serving web cache (108A) server does not possess a copy of the Internet object, it retrieves a copy of the Internet object from the Internet (102) and returns a copy of the Internet object to the web client (110A). The cache name server (106) includes a database that stores an identifier and a serving web cache server ID for each Internet object stored by the plurality of web cache servers (108A-108D). The cache name server database may also store a time stamp for each Internet object. Each web cache server (108A-108D) also includes a database that stores Internet objects and respective time stamps.
Abstract:
A system and method for supporting concurrent message streams. The state machine is used for modeling a digital system having several states. The states represent messages in the digital system. Added to the state machine is a regressive state. The regressive state is connected to each of the states and all transitions between the states go through the regressive state. Also, queues are provided with the state machine to facilitate the concurrent message streams. A queue may be provided with each state so that if multiple message streams are at a single state, they may be stored in the queue provided with the state. Alternatively, a queue may be provided with each message stream so that each queue can keep track of the state at which the corresponding message stream is located.