Parallel Sysplex, multiple LPAR configuration

The Parallel Sysplex® configuration is composed of multiple ARSSOCKD combined library and object servers modules. This type of installation is unique to z/OS® systems and is based on Parallel Sysplex technology.

Although each combined library and object server is installed in a separate LPAR, the Parallel Sysplex technology enables the servers to share the same configuration files, database, JES, HFS, and archive. For performance reasons, all HFS read/write directories that are used for temporary storage of data are configured as being unique to each ARSSOCKD server.

This setup has the advantages of vertical scalability within the parallel sysplex as well as high availability because the failure of any single LPAR only affects the current transactions and a retry sent by the client is automatically routed to one of the active LPARs. The clients connect to the system using a single IP address and port that are associated with a device or program that routes the request to an appropriate ARSSOCKD server. Some systems can route the request according to the z/OS Work Load Manager suggestions, while other devices simply route the requests following a round robin routine.