Marathon Technologies Corporation

Jerry Melnick

Thomas D Bissett

Paul A Leveille

Glenn A Tremblay

Satoshi Watanabe

Ted M Lin

Angel L Pagan

Keiichi Koyama

Stephen S Corbin

A computer system configured to provide fault tolerance includes a first host system and a second host system. The first host system is programmed to monitor a number of portions of memory of the first host system that have been modified by a guest running on the first host system and, upon determining that the number of portions exceeds a threshold level, determine that a checkpoint needs to be created. Upon determining that the checkpoint needs to be created, operation of the guest is paused and checkpoint data is generated. After generating the checkpoint data, operation of the guest is resumed while the checkpoint data is transmitted to the second host system.

Fault tolerant computing systems using checkpoints

A symmetric multiprocessing fault-tolerant computer system controls memory access in a symmetric multiprocessing computer system. To do so, virtual page structures are created, where the virtual page structures reflect physical page access privileges to shared memory for processors in a symmetric multiprocessing computer system. Access to shared memory is controlled based on physical page access privileges reflected in the virtual paging structures to coordinate deterministic shared memory access between processors in the symmetric multiprocessing computer system. A symmetric multiprocessing fault-tolerant computer system may use duplication or continuous replay.

Symmetric multiprocessor fault tolerant computer system

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Wayland, MA, United States of America

Jerry Melnick