Connectivity for high availability

Both the requests to invoke APIs and services in IBM z/OS Connect servers, or RESTful API requests from z/OS applications, are made by using the HTTP protocol, which means that an HA environment can use known TCP/IP load balancing technologies to distribute connections from clients across multiple servers.

• Sysplex Distributor can be used to distribute requests across multiple IBM z/OS Connect servers in a Parallel Sysplex®, with TCP/IP port sharing within each LPAR.

• TCP/IP port sharing can be used to load balance requests across multiple IBM z/OS Connect servers in the same z/OS LPAR.

• WLM classification can be used to classify HTTP traffic in a IBM z/OS Connect server so that it can be managed by z/OS workload management (WLM) along with other work in the system.

By configuring the httpEndpoint in the server configuration file of multiple IBM z/OS Connect servers to listen on the same shared TCP/IP port, clients can send requests to a single hostname and port and allow the TCP/IP load balancing technologies to distribute the request to one of the available servers. IBM z/OS Connect APIs, services, or API requesters have no persistent state and do not use HTTP sessions, so no affinities exist between client applications and IBM z/OS Connect servers, simplifying both workload distribution and the retry of failed requests.