High availability is a key feature of CICS Transaction Gateway on 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 LUW, 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 provided by dynamic feedback to the IBM® z/OS Workload Manager (WLM).