Patent ID: 8793216
Filing Date: 2014-07-29
Classification: G06F

Abstract:
1. A fault-tolerant node for synchronous heterogenous database replication whereby the fault-tolerant node is adapted to carry out a series of database transactions generated by a processor executing a computer program at the fault-tolerant node, wherein the fault-tolerant node comprises at least three relational database management systems, the systems being instances of different relational database management system products which provide snapshot isolation between concurrent transactions and each system comprising a database and a database management component, wherein for each database transaction, operation instructions are provided concurrently to each of the systems to carry out operations on their respective databases and to provide respective responses; wherein the responses generated by the systems comprise either an operation result or an exception, and where only one of the systems is configured with a NOWAIT exception function enabled which returns an exception when it is detected that two or more concurrent transactions are attempting to modify a same data item and all other systems are configured with the NOWAIT exception function disabled, whereby the fault-tolerant node is adapted to detect that two or more concurrent transactions are attempting to modify the same data item and to block one or more of the transactions to ensure that all systems apply a same order of modification of the data item by the concurrent transactions.