07-11-2013 дата публикации
Номер: US20130297970A1
Принадлежит:
Fault tolerant operation is disclosed for a primary instance, such as a process, thread, application, processor, etc., using an active copy-cat instance, a.k.a. backup instance, that mirrors operations in the primary instance, but only after those operations have successfully completed in the primary instance. Fault tolerant logic monitors inputs and outputs of the primary instance and gates those inputs to the backup instance once a given input has been processed. The outputs of the backup instance are then compared with the outputs of the primary instance to ensure correct operation. The disclosed embodiments further relate to fault tolerant failover mechanism allowing the backup instance to take over for the primary instance in a fault situation wherein the primary and backup instances are loosely coupled, i.e. they need not be aware that they are operating in a fault tolerant environment. 1. A computer-implemented method of providing fault tolerant operation to a primary instance , the method comprising:providing a backup instance to which a copy of a first transaction transmitted to the primary instance is forwarded, the backup instance operative to process the copy of the first transaction and generate a first backup result based thereon, the first backup result being transmitted as a response to the first transaction when it has been determined, subsequent to the transmission of the first transaction to the primary instance, that the primary instance is unlikely to transmit a first primary result based on the first transaction, and, based thereon, the primary instance has been prevented from completing an external operation upon which the transmission of the first primary result by the primary instance is dependent.2. The computer-implemented method of further comprising:forwarding, to the backup instance subsequent to the copy of the first transaction, a copy of a second transaction transmitted to the primary instance, when it has been determined that the ...
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