Simply running your workload applications in a parallel sysplex does not ensure that your workloads become continuously available. The z/OS Parallel Sysplex technology is an enabling technology, only. In order for workloads to take full advantage of the highly available properties of a parallel sysplex, their applications need to be able to run instances in parallel on any z/OS system in the cluster and access data in a data sharing environment.

Applications that have affinities may not be eligible to leverage the availability features of a parallel sysplex. A typical example of an affinity is a workload application that has a dependency on non-shared data that is only available locally on one z/OS system. Another case of an application affinity to a single z/OS system is application access to non-shared resources such as an external feed from another company.

IBM Multi-site Workload Lifeline (Lifeline) takes Z Resiliency even further by helping with a continuous availability solution. Lifeline supports a variety of workload types that run on z/OS systems. TCP applications, such as transaction management systems like CICS or IMS, are monitored. Lifeline provides routing recommendations to external load balancers on how to distribute workload connections to these applications.

Lifeline preserves investment in legacy SNA workloads. These SNA applications are monitored for health and availability. Lifeline directs external load balancers to connect to a subset of gateways, such as TN3270, in order to create sessions to specific SNA applications.

For workloads that use messaging services provided by an MQ cluster, the MQ queue managers and cluster queues are monitored. Lifeline controls how MQ messages are delivered to only the eligible MQ queue managers in the MQ cluster.

For customers that have a parallel sysplex and have not or cannot enable data sharing for their workload applications, a good choice for enhancing your resilience is utilizing IBM Multi-site Workload Lifeline along with an appropriate software replication product such as IBM InfoSphere Data Replication (IIDR) for Db2, and possibly an external load balancer. For more information, see IBM Multi-site Workload Lifeline product page.