Dispatch runs with an IDMS database. The journals are used for recoverability. All database updates cause database images to be written to the journals both before and after each update. These journaled images are used to "roll back" any partial modifications to the database, in the event of an abend, in order to maintain and ensure the integrity of the database records and files.
When the IDMS journal files are installed (there are 4 of them), they are installed with a user determined number of blocks that dictate the size of the journal files which in turn determines the number of journaled images that will fit on a particular file. As part of normal everyday processing, eventually a journal file is going to fill up and when it does, Dispatch is going to submit the DSEXJNL1 journal offload job to offload the journaled images to tape so that the space allocated to the journal file can be reused.
As supplied, the DSEXJNL1 jobs control parameters are designed to identify and select a journal for offloading ONLY if a particular journal file is FULL.
A U2109 abend in the DSEXJNL1 job typically means that NO journal files are FULL, so none need to be offloaded. Typically, these U2109 abends in the DSEXJNL1 job can be ignored.
You should see a message:
_ABEND_U2109.TXT: there is no full journal file and
IDMSAJNL UNABLE TO SELECT A DISK JOURNAL FOR OFFLOADING
This could be a timing issue as some clients have setup a journal offload job to be submitted through automation whenever Dispatch is brought down.
If a journal had just been offloaded as part of normal processing right before Dispatch was brought down, then a subsequent journal offload job is submitted by automation, since there are no full journal files, you can get this abend.
For additional information on journaling, please see the Appendix at the back of the Dispatch Systems Programming Guide entitled Appendix A: Troubleshooting and the section on Journal Problems and Questions.