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Deciding which APPC/MVS LUs should be Members of a Generic Resource Group z/OS MVS Planning: APPC/MVS Management SA23-1388-00 |
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Although the use of generic resource names for APPC/MVS LUs can benefit your installation, the mix of transaction programs that your installation uses, and the complexity of the APPC/MVS configuration, affect how easily you achieve those benefits. For example, your installation's current set-up might include many TPs that are handled by one APPC/MVS LU on a single z/OS system in a sysplex. With generic resource support, it is relatively easy to distribute this work among additional LUs on the same z/OS system, or among additional LUs on other systems in the sysplex. To do so requires the following steps:
No changes to the TPs are necessary. For another example, suppose your installation has multiple LUs in the sysplex that process the same work. In this case, using one generic resource name for the group of LUs requires more work than the preceding example:
Your installation may define more than one generic resource group
in its APPC/MVS configuration, but not all APPC/MVS LUs have to belong
to a group. Those LUs in a group, however, must have access to all
the same resources; they should:
For the TPs running on LUs in a generic resource group, make sure that all the TPs specify the generic name of the MVS LU on the Allocate request. Otherwise, if you allow some TPs to use the generic name, and others to use the specific name, timing becomes the key to successful allocation requests, even for TPs that ran reliably before. For example, suppose your installation has set up a configuration
like the one in Figure 1, which shows two
TPs that run on the workstation:
On the host, two APPC/MVS LUs share a generic resource name: LUA and LUB are both known by the generic name MVSLU. Figure 1. APPC/MVS Configuration with
a Mix of Allocate Requests to Specific and Generic LU Names
To understand the problem with allowing the use of a mix of specific and generic LU names on Allocate requests, consider the following sequence of events:
Other timing problems might result because, with generic resource
groups, the system fails the Allocate request when both of the following
are true:
To prevent such failures because of timing, make sure you assign several LUs to the same group, and make sure all the TPs that run on LUs in the group use the generic resource name on the Allocate request. To reduce the amount of work required for the latter step, use an existing, specific LU name as the name for the generic resource group. |
Copyright IBM Corporation 1990, 2014
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