Figure 1. Syntax

The NoDup option specifies duplicate fault detection thresholds.

There are two distinctly different types of duplicate fault detection, depending on the execution environment:

  • Fast duplicate detection:

    Applicable to CICS® or IMS:

    • CICS® fast duplicate detection is controlled by the CICSFAST suboption of the NoDup option (see NoDup(CICSFAST(…))).

      The scope of duplicate detection is limited to a single CICS® region.

    • IMS fast duplicate detection is controlled by the ImageFast(IMS) suboptions of the NoDup option (see NoDup(ImageFast(…))).

      The scope of duplicate detection is across the entire MVS image.

    The purpose of fast duplicate detection is mainly to prevent multiple identical abends, which all occur within a relatively short period of time, from unnecessarily slowing down abend recovery by only permitting one fault analysis of each unique problem within the specified period. Since the detection of duplicate faults must occur prior to fault analysis, the criteria differs from that used for normal duplicate detection.

    Faults that have not been deemed duplicates based on the "fast" duplicate detection rules are subsequently subject to "normal" duplicate detection.

  • Normal duplicate detection:

    Applicable to all execution environments,

    Controlled by the NORMAL suboption of the NoDup option (see NoDup(NORMAL(…))).

    The purpose of normal duplicate detection is to prevent multiple identical faults from being recorded separately in a history file, thus assisting with DASD space preservation as well as maintaining a history file containing only entries which represent unique problems.

Regardless of the method used to designate a fault as a duplicate, the fault entry of which it is a duplicate has its duplicate count incremented accordingly.

This option applies to the real-time analysis only.

If NoDup(NORMAL(hours, …)) is in effect, with a non-zero value of hours, then this option is included in the section of the fault analysis report that shows options in effect. In addition, information about whether no duplicate fault was determined, or the fault ID of any identified duplicate, is provided. NoDup(CICSFAST) or NoDup(ImageFast) option information is not included, since no report is written if the associated duplicate criteria matched.

While the syntax for each duplicate subtype is shown separately in the following, they can be specified together in a single NoDup option if desired.