z/OS DLA discovery detail

z/OS® DLA starts by discovering the zSeries hardware and the instance of z/OS where the discovery job runs not necessarily where it is installed. The z/OS DLA can discover the following zSeries virtualization:
  • Sysplex
  • z/VM® Guest
  • PR/SM partitioning of the CPC

This resulting discovery information is produced as output that is sent to the ZOSBASE book.

Next, z/OS DLA discovers all z/OS address spaces and examines them to see if it recognizes any subsystems. You can do the same at your z/OS keyboard by going to TSO SDSF Display Active (=SDSF.DA) to see if an application (WAS, Db2® or NetView) is running. z/OS DLA also examines TCP/IP connections to discover network connectivity and assess which subsystems might be interconnected. This discovery information is sent as output to the ZOSTASK book.

Every z/OS DLA discovery produces one ZOSBASE book and one ZOSTASK book. Depending on what is installed on the LPAR, you can get dozens of additional books for Db2, MQ, CICS®, and other subsystems.

When z/OS DLA recognizes a subsystem (ex. A Db2 subsystem) that is up and running, it creates 1 book with the name of the master or control address space for that subsystem.

In one system (one LPAR), there can be an address space named D81DMSTR. The z/OS DLA creates a D81DMSTR book to represent that instance of Db2 (v12). You might also have a D91AMSTR book for that LPAR. A Db2 instance (one book) can include several lower-level Db2 tablespaces and databases.
Note: The unmodified z/OS DLA can discover zSeries, zSeries virtualization, z/OS systems, and z/OS application subsystems (such as CICS Region C88RLB5). Discovering lower-level detail requires that you change the default filters.
Important: Do not assume that in a z/OS DLA book you will automatically see all the resources that can be discovered. You can review filter settings in the FILT directive, or look at the sample IZDCDEF customization member. If a resource is not up and running at the time the discovery job is run, it will not be discovered.
The z/OS DLA filters out lower-level detail for the following reasons:
  • One product can take much longer than another to load in all the discovered resources.
  • A slow screen-refresh at the product can cause confusion to operators.
  • A highly populated consuming product database can cause slow screen-refresh and overload operators with thousands of resources and lines interconnected on-screen.

One useful way to see zSeries resource detail without incurring the burden of loading thousands of low-level resources, is to use z/OS DLA support for CDM ZReportFiles. For example, z/OS DLA can create ZReportFiles that list all CICSTransactions, all Db2 databases and all z/OS PARMLIB definitions.

These text files contain most of the detail you might see in 2040 individual CICS Transaction objects. You can view these reports in TADDM detail, but you cannot see the individual transactions as icons in a topology layout or as rows in a detail window table. You can run TADDM or CCMDB Change Configuration against ZReportFiles to see what has changed since a prior discovery.