Stratus Computer, Inc.

John D Service

Bradford B Glade

Kenneth P Birman

Fred B Schneider

John E Ahern

Robert C Cooper

Thomas C Bressoud

Arthur James Beaverson

Charles J Horvath

Richard Urmston

Walter A Jones, Jr

Jeffrey D Carter

John T Vachon

Matthew A Trask

In a fault-tolerant computer system, a primary replica supervisor is interposed between an operating system and a primary replica of an application program being executed by a primary processor. An object-code editor locates calls to the operating system and loops in the application program and inserts instruction sequences that enable the replica supervisor to intercept the calls to the operating system, results returned by the operating system as a result of the calls and asynchronous events delivered by the operating system to the replica. A backup replica supervisor is similarly interposed between an operating system and a backup replica of the application program being executed by a backup processor. The primary replica interacts with an environment. The replica supervisors ensure that the backup replica undergoes state transformations, as a result of the calls to the operating system and asynchronous events, that are equivalent to state transformations that the primary replica undergoes as a result of corresponding calls and asynchronous events. Thus, after a failure in the primary processor, the backup replica can interact with the environment in a manner consistent with interactions between the primary replica and the environment prior to the failure.

Transparent fault tolerant computer system

A console terminal arrangement is disclosed for use in connection with a fault-tolerant computer system including a plurality of processing modules, at least some of the processing modules including an operator input/output interface for receiving operator input from an operator input device and operator display output on an operator display device. The console terminal arrangement facilitates management of all of the processing modules by a single operator from a single location. The arrangement includes a console terminal and a plurality of processing module interfaces interconnected by a network. The console terminal includes an operator input device and an operator display device, and generates operator input messages including processing module management information generated by the operator input device in response to inputs provided by an operator and an address identifying one of the processing modules to be managed by the console terminal. The console terminal further generates and displays video images in response to video image data received in messages from the processing modules. Each processing module interface receives operator input messages generated by the console terminal which include an address identifying the processing module connected to the processing module interface and provide the processing module management information to the operator input/output interface to control the processing module. In addition, each processing module interface receives video information from the associated processing module's operator input output device and generates a message including the video information and an address identifying the console terminal. The network carries messages generated by the console terminal and the processing module interfaces in accordance with the addresses contained in the respective messages.

System console terminal for fault tolerant computer system

Growing community of inventors

Chelmsford, MA, United States of America

John D Service