Preventing bottlenecks

You can avert performance-related problems by regular examination of information that can identify potential problems. Consider performing these tasks as regular intervals:

• Examination of the IBM Tivoli Workload Scheduler for z/OS statistics generated when the STATMSG keyword is defined in the OPCOPTS initialization statement.
• Regular reorganizations of the VSAM clusters: EQQADDS, EQQRDDS, EQQSIDS, and EQQOIDS.
• Monitor IDCAMS LISTCAT output of the VSAM clusters to ensure optimum allocation. Increase the free space allocation if CI and CA splits are frequently occurring. Reallocate the cluster with a large primary allocation if it has extents.
• Review the message log (EQQMLOG) to identify how often and when the CP and JS backups are occurring.
• Educate the user community on how they can avoid long-running dialog requests:
  • Encourage the use of FASTPATH options where available.
  • Use generic search characters only when required. Specify as much information as possible to limit the search.
  • Familiarize users with the key structure of the VSAM clusters. Try to build dialog selection criteria with consideration of the key to prevent sequential searches of the clusters.