Management of cluster-wide resources with shared variables

摘要

The number of concurrent systems locks supported on a Sysplex is limited. Since persistent system locks may not be released for a long time, the limit may be reached resulting in outage periods. Access to resources may be managed through shared variables across a cluster of computing systems. Processes running on the cluster can use shared variables that are either exclusive or non-exclusive. An exclusive shared variable associates a resource with a process that has exclusive control of the resource. Since each exclusive shared variable is unique across the cluster, another application cannot create a second exclusive shared variable to control the resource. There is no limit on the number of exclusive shared variables that can be created on a cluster. Using exclusive shared variables instead of persistent system locks can prevent a system from reaching the limit of concurrent system locks while allowing processes exclusive use of resources.