AUGMENTED ADVISORY LOCK MECHANISM FOR TIGHTLY-COUPLED CLUSTERS

摘要

An inter-machine locking mechanism coordinates the access of shared resources in a tightly-coupled cluster that includes a number of processing systems. When a requesting processing system acquires a lock to access a resource, a comparison is made between values of a global counter and a local counter. The global counter indicates the number of times the lock is acquired exclusively by any of the processing systems. Based on the comparison result, the requesting processing system determines whether the resource has been modified since the last time it held the lock.