The transaction recovery journal file is separate from the system journal files and acquires various types of information about transactions at each transaction branch (that is, each UAP process). A transaction recovery journal file is created as a UNIX file with the name of trfxxxxxxxx (where x indicates an integer) in the $DCDIR/spool/dctjlinf/ directory. Therefore, no transaction recovery journal file can be used in a System Switchover configuration.

In the user service definition for each service group, you can define whether to obtain a transaction recovery journal file. This file overcomes problems such as the following:

• In transaction processing that spans multiple UAP processes, one process taking a long time might cause multiple system journal files to obtain journal information for the resources updated in a transaction. If online processing stops during transaction processing, all those system journal files must be read to recover the resources. If all such files must be read, recovery will take a long time.
• A system journal file that is being used cannot be swapped so it is possible that, depending on the size and number of the system journal files, before the end of a transaction's processing there might be no system journal files that can be swapped. If no system journal files can be swapped, OpenTP1 terminates abnormally.

To avoid the above problems, you can use the user service definition to specify a special file in which OpenTP1 stores the journal (i.e., information) about a transaction that takes a long time. This special file is a transaction recovery journal file which is separate from the system journal files. By creating a transaction recovery journal file, you can reduce the number of journals that are read at recovery. Also, even when processing of a transaction takes a long time, system journal files can be swapped and checkpoint dumps can be effective. These results can reduce the time required for recovery at a restart.

Using a separate transaction recovery journal file also helps to prevent those OpenTP1-system abnormal terminations caused by long transaction processing times producing overflows of journal information. We recommend that you use a transaction recovery journal file for UAPs that have long processing times. When you use a transaction recovery journal file, however, the same journal is collected in both the system journal file and the transaction recovery journal file. This might slow down transaction processing.

When an error occurs in a transaction recovery journal file during restart processing, OpenTP1 outputs a message to report this situation. When this message is output, use the command jnlmkrf to recover the transaction recovery journal file. Use the unloaded-journals file to recover the transaction recovery journal file.