Resetting the queue manager's log
Use this topic to understand how to reset the queue manager's log.
You must not allow the queue manager log RBA to wrap around from the end of the log RBA range to 0, as this leads to a queue manager outage and all persistent data will become unrecoverable. The end of the log RBA is either a value of FFFFFFFFFFFF (if 6-byte RBAs as in use), or FFFFFFFFFFFFFFFF (if 8-byte RBAs are in use).
The queue manager issues messages CSQI045I, CSQI046E, CSQI047E, CSQJ031D, and CSQJ032E to indicate that the used log range is significant and that you should plan to take action to avoid an unplanned outage.
The queue manager terminates with reason code 00D10257 when the RBA value reaches FFF800000000 (if 6-byte log RBAs are in use) or FFFFFFC000000000 (if 8-byte log RBAs are in use).
If 6-byte log RBAs are in use, consider converting the queue manager to use 8-byte log RBAs rather than resetting the queue manager's log, following the process described in Implementing the larger log Relative Byte Address. Converting a queue manager to use 8-byte log RBAs requires a shorter outage than resetting the log, and increases the period of time before we have to reset the log.
Message CSQJ034I, issued during queue manager initialization, indicates the end of the log RBA range for the queue manager as configured, and can be used to determine whether 6-byte or 8-byte log RBAs are in use.
The procedure to follow to reset the queue manager's log is as follows:
- Resolve any unresolved units of work. The number of unresolved units of work is displayed at queue manager startup in message CSQR005I as the INDOUBT count. At each checkpoint, and at queue manager shutdown, the queue manager automatically issues the command
DISPLAY CONN(*) TYPE(CONN) ALL WHERE(UOWSTATE EQ UNRESOLVED) to provide information about unresolved units of work.
See How in-doubt units of recovery are resolved for information on resolving units of recovery. The ultimate recourse is to use the RESOLVE INDOUBT MQSC command to manually resolve indoubt units of recovery.
- Shut down the queue manager cleanly.
We can use either STOP QMGR or STOP QMGR MODE(FORCE) as both these commands flush any changed pages from bufferpools to the pagesets.
- If a queue manager is part of a queue sharing group, take CFSTRUCT backups on other queue managers for all structures in the queue sharing group. This ensures that the most recent backups are not in this queue manager's log, and that this queue manager's log is not required for CFSTRUCT recovery.
- Define new logs and BSDS using CSQJU003 (see The change log inventory utility for more information on using the change log inventory utility).
- Run CSQUTIL RESETPAGE against all the page sets for this queue manager (see Copying a page and resetting the log for more information on using this function). Note that page set RBAs can be reset independently, so multiple concurrent jobs (for example, one per page set) can be submitted to reduce the elapsed time for this step.
- Restart the queue manager