MII setup for SYS1.DAELIB in Sysplex/MIMplex

Products

• MIM Resource Sharing (MIM)

Issue/Introduction

How to correctly setup MIM for SYS1.DAELIB to be shared across a MIMplex of 'n' way Parallel SYSplex

Environment

Release :  

Component : MII

Resolution

The IBM directions in this area can be found at the following link:

Using DAE in a Sysplex Z/OS 2.4

...Dump analysis and elimination (DAE) allows an installation to suppress SVC dumps and SYSMDUMP ABEND dumps that are not needed because they duplicate previously written dumps. To identify the cause of previous and requested dumps, DAE uses symptom strings, which contain data that describes a problem. DAE stores these symptom strings in a DAE data set that you provide.

You can use the DAE data set in a single-system environment, or the systems in a sysplex can share a single DAE data set. The way you use the DAE data set determines how you specify the data set to global resource serialization to avoid contention for that data set....

Using DAE in a Sysplex

The shared DAE data set, if it is not named SYS1.DAE, is already set up as a global resource. IBM suggests that you provide a name other than SYS1.DAE for the DAE data set to be shared in the sysplex because then you do not need to change the data set definition for global resource serialization.

For a sysplex, the default RNL contains the generic qname entry SYSDSN in the SYSTEM inclusion RNL. An entry is not needed in the SYSTEMS exclusion RNL for a global resource.

Note: If you intend to use SYS1.DAE as the shared DAE data set for a sysplex, you must remove the specific rname entry for the SYS1.DAE data set from the default SYSTEMS exclusion RNL.....

Based on the above and if the GDIEXMPT member contains the statement :

LOCAL    QNAME=SYSDSN,RNAME=SYS1.DAE 

then it should be removed for SYS1.DAE since the resource will be shared. This change can be done dynamically issuing the command: 

F MIM, EXEMPT GLOBAL QNAME=SYSDSN, RNAME=SYS1.DAE

This command needs to be issued on each system in the MIMPLEX as it is a local command, as reported at the following link in the documentation:

(MII) EXEMPT Command-Modify Exempt List

 

...The EXEMPT command lets you modify the exempt list, which provides GDIF with supplemental and more specific information on propagating ENQ requests and handling hardware reserves. This command is available only when you are running the GDIF of the MII component.

Scope: Local ...

The EXEMPT LOCAL statement should then be removed from the GDIEXMPT member, so that it is not re-added at the next recycle of MII.

If the statement in GDIEXMPT looks like:

LOCAL    RNAME=SYS1.DAE 

then the dynamic command to remove it is the following:

F MIM, EXEMPT GLOBAL RNAME=SYS1.DAE