Tuning GRS when using global transactions in z/OS
WebSphere® Application Server for z/OS® uses global resource serialization (GRS) to communicate information between servers in a sysplex. When there are multiple servers defined in a system or a sysplex, a request might end up on the wrong server. WebSphere Application Server for z/OS uses GRS to determine where the transaction is running.
About this task
If you are using global transactions, WebSphere Application Server for z/OS issues an enqueue for a transaction when the transaction starts and holds on to that enqueue until the transaction ends.
If you are not in a sysplex, you should configure GRS=NONE, or if you are in a sysplex, you should configure GRS=STAR.
This requires configuring GRS to use the coupling facility. All of the WebSphere Application Server enqueues are issued with RNL=NO, which prevents misconfiguring the GRSRNLxx with inappropriate values. See the GRS documentation for details on setting this up.
- Must be different from the cell name of any servers running in the sysplex
- Must be different from the cell name of any servers running in another monoplex that is attached to the sysplex
Procedure
- If you are not in a sysplex, configure GRS=NONE.
- If you are in a sysplex, configure GRS=STAR.