z/OS - Detect Catalog Alias Record Filling Up
Original Publication Date: 2005-May-18
Included in the Prior Art Database: 2005-May-18
REXX Exec can be used to proactively determine when z/OS catalog alias records are nearing full so that appropriate measures can be taken in order to prevent errors on future alias define activity.
z/OS - Detect Catalog Alias Record Filling Up Disclosed here is a program which allows for a proactive approach to dealing with the problem of catalog alias records filling up in the z/OS environment.
The structure of master catalogs in the z/OS environment is such that "alias" entries in the master catalog are used to connect user catalogs to the master catalog. When the operating system searches for a file (data set), the first node(s) in the data set name are indexed to an alias in the master catalog, which in turn determines which user catalog should be searched in order to locate the data set. Because there can only be one record associating a user catalog to all of its aliases, this record can fill up if too many alias entries are defined for the user catalog. When this happens, the system will simply not allow any further aliases to be defined for the user catalog. Many automated systems are in place in larger environments for defining alias entries, and alias creation failure may not be detected until a serious outage situation occurs. What is needed is a process for determining when the catalog connector record in a master catalog is approaching the full point, so that pre-emptive actions can be taken. Such actions might include using an alternate user catalog, defining a new user catalog, or cleaning up (removing unused alias entries) for the affected catalog. This publication documents a REXX EXEC which can be used to detect a possible problem, and notify the appropriate support personnel. To my k...