Journal object limit

 

The journal object limit (JRNOBJLMT) parameter allows you to set the maximum number of objects that will be allowed to be journaled to the journal.

The journaled object limit is the maximum number of objects that can be journaled to one journal. You can set the journal object limit to either 250 000 or 10 00 000. Use the Journal Object Limit (JRNOBJLMT) parameter on the Create Journal (CRTJRN) or Change Journal (CHGJRN) command to set the maximum number of journaled objects.

The value *MAX10M can only be specified for the Journal Object Limit (JRNOBJLMT) parameter if the Receiver Size Option (RCVSIZOPT) parameter has one of the receiver maximum values specified, or if RCVSIZOPT is *SYSDFT.

Some factors to consider in determining the journal object limit are:

• Number of objects that would be actively changing at any given time

• The impact journaling has on the performance of your system

• Importance in being able to get some parallelism at IPL, run-time, hot-site apply, and high-availability (HA) replay time

• Complexity of managing your journal environment with multiple journals

• Complexity of your hot-site recovery procedures if you have dependencies between objects journaled to different journals

• Number of objects you may need to journal in the future

• Increasing the quantity of objects associated with a single journal may increase your IPL time, independent ASP vary on time, or disaster recovery time. As a general rule, if the number of actively changing objects is likely to be greater than 5 000, consider journaling some of these objects to a separate journal. The larger the number of actively changing objects for a given journal at system termination, the longer it will take to recover the journal at IPL or vary on of an independent ASP.

*MAX250K

The maximum number of objects that can be journaled to one journal is 250 000. This is the default value.

*MAX10M

The maximum number of objects that can be journaled to a single journal is 10 000 000. A journal employing this attribute cannot be saved and restored to any releases prior to V5R4 nor can it be replicated to any remote journals on any systems prior to V5R4.

Once you have chosen the *MAX10M option, you cannot switch back to the *MAX250K value.

If the number of currently journaled objects is greater than the maximum number of journaled objects, a start journal request will fail.

A new receiver must be attached at the same time as this value is changed.

 

Parent topic:

Planning setup for journals