Using the ESS Exit
Each record passed to the exit consists of a record header and an event record. DGA$NHDR, in $CD.SDGAMAC, maps the record header. Other members in $CD.SDGAMAC map the event records. See Event Services Record, to determine which member maps a particular event record.
The exit must reside in a load library accessible to the IBM Connect:Direct server (DTF). This exit accommodates systems where I/O calls must be done below the line.
To use the ESS user exit:
- Create an ESS exit program that can process the requested event records.
- Decide what event data your application requires.
- Verify that your software is correctly installed and working.
- Create an ESS registration program. Include this program
in the startup portion of your application. It is called whenever
your application initiates event record collection. This program must
accomplish the following tasks:
- Signon to IBM Connect:Direct through the CICS API, the ISPF IUI, or the batch interface.
- Issue the EVENT SERVICES CREATE command to register interest in receiving event data and specify event record filter criteria.
- Specify the EXIT parameter to identify the name of your exit program, and the ID parameter to identify a subscriber name for your application. Specify the WHERE and ORWHERE parameters for your filtering criteria. Refer to EVENT SERVICES CREATE Command Format for more information about event filter criteria.
- Issue the EVENT SERVICES START command and specify the ID parameter to initiate event reception.
Embed a call to the EVENT SERVICES STOP ID=subscriber_name parameter in your application where you want to stop collecting event data. If the user application does not process records fast enough, the internal queue, which holds asynchronous events, becomes full. When the queue is full, event processing for this request ends, and Connect:Direct writes a WTOR message. To customize the internal queue size, specify the MAXQCNT parameter.