Microsoft Technology Licensing, LLC

Philippe Choquier

William James Griffin

Jean-Francios Peyroux

Ramon J San Andres

Jean-Francois Peyroux

Richard G Greenberg

A generic transaction replication service receives update transactions from individual application servers, and forwards the update transactions for processing to all application servers that run the same service application, thereby enabling each application server to maintain a replicated copy of service content data. Upon receiving an update transaction, the application servers perform the specified update, and asynchronously report back to the transaction replication service on the 'success' or 'failure' of the transaction. When inconsistent transaction results are reported by different application servers, the transaction replication service uses a voting scheme to decide which application servers are to be deemed 'consistent,' and takes inconsistent application servers off-line for maintenance. Each update transaction replicated by the transaction replication service is stored in a transaction log. When a new application server is brought on-line, previously-dispatched update transactions stored in the transaction log are dispatched in sequence to the new server to bring the new server's content data up-to-date.

Transaction replication system and method for supporting replicated

An on-line services network includes application servers and Gateway microcomputers that are interconnected by a LAN. The Gateway microcomputers receive service requests which are transmitted over a WAN from client microcomputers operated by end users. Upon receiving a request to open a service, the Gateway microcomputers access a periodically-updated service map to locate the replicated application servers that are currently running the corresponding service application, and then apply a load balancing method (using server load data contained within the service map) to select an application server that has a relatively low processing load. A communications protocol between the client and Gateway microcomputers enables users to access multiple services simultaneously. A hot redirection technique allows a user service session to be transferred from one application server to another (replicated) application server without termination of the service session. Various mechanisms are provided for efficiently reallocating application servers to different on-line services, and for allowing additional servers to be efficiently added to the network.

Method of redirecting a client service session to a second application

System for on-line service in which gateway computer uses service map

Growing community of inventors

Paris, France

Philippe Choquier