Using the Z Abend Investigator HFZS subsystem

Z Abend Investigator uses a subsystem known as HFZS for services that can otherwise not be performed or which might cause incomplete analysis if not started.

A separate HFZS subsystem is required on each MVS™ image that runs Z Abend Investigator.

Z Abend Investigator uses the HFZS subsystem to:
  • Verify that the Z Abend Investigator license is not expired and that the environment where Z Abend Investigator is running matches the environment registered in the license certificate. To ensure that Z Abend Investigator execution is not interrupted, periodically check the license status in the HFZS subsystem log.
  • Connect to DB2® subsystems to read the catalog if the connection failed from the abending address space. These connection failures cause the following message to be issued in the abending address space.
    HFZ0082E DB2 Call Level Interface error: SQL return code -1 for SQLAllocConnect
    to DB2 system system-id
  • Register SVC dumps on behalf of the HFZXTSEL post-dump exit. This registration is primarily intended for CICS® system dumps and to facilitate the capturing of Java™ faults.
  • Perform history file access management if PDSESHARING(NORMAL) is used, in order to reduce abend S213-70 cross-system sharing conflicts.
  • Optionally, manage history file $$INDEX members for improved performance. While this feature is the default for eligible history files, it can be disabled by specifying the NOUPDINDEX PARM field option for the HFZS subsystem, as described in Starting the HFZS subsystem. For details, see Caching of history file $$INDEX data.
  • Optionally, enable IMS fast duplicate fault suppression specified using the NoDup(ImageFast(minutes,IMS(…))) option. While this feature is the default, it can be disabled by specifying the NOUPDINDEX or NOIMAGEFAST PARM field option for the HFZS subsystem, as described in Starting the HFZS subsystem. For details of the NoDup(ImageFast(minutes,IMS(…))) option, see NoDup.
  • Optionally, enable fast Exclude options processing. While this feature is the default, it can be disabled by specifying the NOFASTEXCLUDE PARM field option for the HFZS subsystem, as described in Starting the HFZS subsystem. For details, see Fast Exclude options processing.
  • Provide recovery fault recording support. (For general information about recovery fault recording, see Recovery fault recording.)
  • Provide improved performance of message and abend code explanation retrieval for the Z Abend Investigator ISPF interface LOOKUP command by caching information in storage. Additionally, perform automatic updates of the VSAM KSDS message and abend code explanation repository when required. Refer to Setting up the message and abend code explanation repository for information about required access authorization.
  • Provide Java analysis support by means of the Java-supplied Diagnostic Tooling Framework for Java (DTFJ). The DTFJ process runs from the BXPAS address space, which is spawned from the HFZS subsystem when the PARM='JAVA' option is used in the HFZS subsystem startup JCL.
  • Perform reading of message and abend explanations from source data sets, as well as caching of selected explanations for improved performance.
  • Delete migrated tightly coupled dump data sets when the associated fault entry is deleted.

The HFZS subsystem should not be prioritized lower than any of the tasks for which it might be invoked. Assigning a high priority to the HFZS subsystem does not affect system performance adversely, since no resources are consumed by the HFZS subsystem when it is not in use.

The HFZS subsystem must be defined to the security system with an OMVS UID value.