WebSphere® Application Server for z/OS® uses Resource Recovery Services (RRS) to support two-phase transaction commit.
Normally, all systems in a sysplex share a common set of RRS logs for syncpoint processing. If you want to associate specific systems in a sysplex for syncpoint processing, you can specify a log group name when you start RRS. The default log group name is the sysplex name. If you specify a different log group name when you start RRS, it will coordinate syncpoint processing with all systems in the sysplex that use the same RRS log group name.
Resource recovery services log streams
If using coupling facility log streams, the RRS images on different systems in a sysplex run independently but share log streams to keep track of the work. If a system fails, an instance of RRS on a different system in the sysplex can use the shared logs to take over the failed system's work.
Use DASD-only log streams only in either single system sysplexes with one RRS image or a sysplex in which information should not be shared among RRS images.
In a multiple-system sysplex, RRS log streams should normally reside in a coupling facility.
All RRS transaction logging for WebSphere Application Server for z/OS will occur solely in the DELAYED.UR log stream. You can still configure your MAIN.UR log stream so that it can handle a production workload in case you deploy a new container or the WebSphere Application Server for z/OS infrastructure changes. WebSphere Application Server for z/OS has no significant impact on the RM.DATA or RESTART logs.
Use the following steps to configure RRS.