Playback utility overview

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By using the IMS online log data sets (OLDS) and system log data sets (SLDS) as input, the Playback utility formats the transaction log into transaction screen images.

The IMS OLDS and SLDS traditionally are used to maintain IMS system integrity, but users have often found many other uses for the data on the logs.

Transaction queue-related data is contained on the IMS log as '01'x records (INPUT MESSAGE QUEUED) and '03'x records (OUTPUT MESSAGE QUEUED). These records contain, among other things, information that identifies the user who initiated the transaction, the terminal from which it originated, and the target to where the data is being sent. The data that will be processed by the application program or displayed on a terminal is also contained on these records.

One of the functions of IMS Batch Terminal Simulator is to simulate transaction processing in batch mode. To accomplish this, IMS Batch Terminal Simulator uses the MFS format library to format the transaction data into a screen display. As part of its function, IMS Batch Terminal Simulator processes the ISRT calls that are issued by an application program to the message queue.

The Playback utility uses these functions of IMS Batch Terminal Simulator to create its report.

Functions

The function of the Playback utility is to create a file of screen images that correspond to the transaction activities captured in an IMS OLDS or SLDS.

The Playback utility provides the following functions:

  • Queries RECON data sets to find log data set names.
  • Finds and extracts the data part of an IMS log record.
  • Finds the MOD name in the IMS log record, and extracts it.
  • Finds and extracts the data that identifies the user ID, the logical terminal (LTERM) name, the transaction code, and the logged time in the IMS log record.
  • Issues DLI ISRT calls to drive IMS Batch Terminal Simulator through its normal functions, which include formatting a screen based on the information in the data.
  • Edits the screen that results from IMS Batch Terminal Simulator and appends the previously extracted data related to user identification.

Because the application programs that initially generated the messages are never called, and the associated databases are never accessed, the application programs or the databases are not needed by Playback processing.

Features and benefits

The Playback utility is designed to provide users with an easy-to-use, flexible tool to translate the queue log records into a readable format. Although the default processing mode is set to select and process all records, the utility can selectively process a subset of the records based upon the selection criteria that is driven by the control statement.

The Playback utility uses standard IMS DL/I calls to ensure that it functions correctly with all levels of IMS.

The reports and files that are generated by the Playback utility can be used to:
  • Monitor IMS transaction activity
  • Create an audit trail of transactions
  • Track activity of specific users or transactions
  • Create a history of IMS transaction activity
  • Determine which MODs are active in a system in order to discover unused format blocks
  • Provide a tool for technical support personnel and application administrators

You can use the Playback utility to create the following output:

  • A list of the transaction codes that have executed within an IMS log
  • A list of the user IDs that have executed transactions within an IMS log
  • A list of the MFS MOD names that have been involved with transactions within an IMS log
  • A list of the transaction codes that have been executed, cross referenced by the user IDs that scheduled them, within an IMS log
  • Screen images that are associated with the transactions within an IMS log

With the Playback utility, you can:

  • Specify which user IDs you are interested in tracking
  • Specify which transactions you are interested in tracking
  • Specify which transactions you are not interested in tracking
  • Specify which terminals you are interested in tracking
  • Specify which terminals you are not interested in tracking
  • Specify which MFS MODs you are interested in tracking
  • Specify which MFS MODs you are not interested in tracking
  • Specify which log type you are not interested in tracking
  • Narrow your search to specific time intervals in the log
  • Skip records in the IMS log or extraction files before beginning your search
  • Process a subset of the records in the IMS log or extraction files
  • Restart the process after errors have prematurely terminated the process
  • Run IMS Batch Terminal Simulator as a batch program (DLI/DBB)
  • Process data from any source that has been converted to match formats used by the Playback utility