Special members in the history file data set

If listing the members of a history file data set with ISPF or similar, you might notice members whose names start with "$$". These are not fault entries, but instead internal control members used by Fault Analyzer:
$$INDEX
This member contains an index of all fault entries in the history file and is used for quick access to basic information for each fault. It is also the sole repository for all duplicate information against any fault in the history file.
If the $$INDEX member is missing for any reason, then it is rebuilt the next time the history file is updated. This situation might happen, for example, when real-time analysis causes a new fault entry to be created, or when user-information for an existing fault entry is updated.
Note: The rebuilt $$INDEX member does not contain any information about duplicate fault occurrences.

A sample assembler program, which can be used as the basis for user-specific reporting or statistical analysis of a history file $$INDEX member, is available as member IDIS$NDX in data set IDI.SIDISAM1.

$$BACKUP
This member contains a copy of the history file specific settings that have been set in the $$INDEX member by using the IDIUTIL batch utility SetFaultPrefix, SetMaxFaultEntries or SetMinFaultEntries control statements (for details, see Managing history files (IDIUTIL utility)), or by using the Fault Analyzer ISPF interface (for details, see Change fault history file settings). If, for any reason, the $$INDEX member information is lost, then these settings are recovered from the $$BACKUP member.