High availability

High availability is a key feature of CICS® Transaction Gateway on IBM® z/OS®. With a system solution that delivers high availability, any single failure does not cause failure of the total solution and increased capacity can be provided by adding additional components. High availability is available for all types of ECI request, including SYNCONRETURN, extended logical UOW, two-phase commit XA transactions and all types of ESI request.

High availability of the Gateway daemon uses TCP/IP load balancing to spread connections across a highly available Gateway group. You can also increase the efficiency of your load balancing function by taking account of CICS server status that is provided by dynamic feedback to the IBM z/OS Workload Manager (WLM).

For deployments that use local mode IPIC connections to CICS from IBM WebSphere® Application Server, the ECI connection factory can benefit from the automatic fail over capability that is provided in IBM WebSphere Application Server. The automatic fail over and fail back capability is supported when connected to CICS TS V4.1 and later. For more information, see Configuring automatic fail over in IBM WebSphere Application Server.