Journal receiver management - assure_mimix - 10.0

Assure MIMIX Administrator Reference

Product type
Product family
Assure MIMIX™ Software
Product name
Assure MIMIX
Assure MIMIX Administrator Reference
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Parameters in journal definition commands determine how change management and delete management are performed on the journal receivers used by the replication process. Shipped default values allow MIMIX to perform change management and delete management.

Change management - The Receiver change management (CHGMGT) parameter controls how the journal receivers are changed. The shipped default value *TIMESIZE results in MIMIX changing the journal receiver by both threshold size and time of day.

Additional parameters in the journal definition control the size at which to change (THRESHOLD), the time of day to change (TIME), and when to reset the receiver sequence number (RESETTHLD2 or RESETTHLD). The conditions specified in these parameters must be met before change management can occur. For additional information, see Tips for journal definition parameters.

If you do not use the default value *TIMESIZE for CHGMGT, consider the following:

  • When you specify *TIMESYS, the system manages the receiver by size and during IPLs and MIMIX manages changing the receiver at a specified time.

Note: The value *TIME can be specified with *SIZE or *SYSTEM to achieve the same results as *TIMESIZE or *TIMESYS, respectively.
  • When you specify *NONE, MIMIX does not handle changing the journal receivers. You must ensure that the system or another application performs change management to prevent the journal receivers from overflowing.

  • When you allow the system to perform change management (*SYSTEM) and the attached journal receiver reaches its threshold, the system detaches the journal receiver and creates and attaches a new journal receiver. During an initial program load (IPL) or the vary on of an independent ASP, the system performs a CHGJRN command to create and attach a new journal receiver and to reset the journal sequence number of journals that are not needed for commitment control recovery for that IPL or vary on, unless the receiver size option (RCVSIZOPT) is *MAXOPT3. When the RCVSIZOPT is *MAXOPT3, the sequence number will not be reset and a new journal receiver will not be attached unless the sequence number exceeds the sequence number threshold.

In a remote journaling configuration, MIMIX recognizes remote journals and ignores change management for the remote journals. The remote journal receiver is changed automatically by the IBM i remote journal function when the receiver on the source system is changed. You can specify in the source journal definition whether to have receiver change management performed by the system or by MIMIX. Any change management values you specify for the target journal definition are ignored.

You can also customize how MIMIX performs journal receiver change management through the use of exit programs. For more information, see Working with journal receiver management user exit points.

Delete management - The Receiver delete management (DLTMGT) parameter controls how the journal receivers used for replication are deleted. It is strongly recommended that you use the value *YES to allow MIMIX to perform delete management.

When MIMIX performs delete management, the journal receivers are only deleted after MIMIX is finished with them and all other criteria specified on the journal definition are met. The criteria includes how long to retain unsaved journal receivers (KEEPUNSAV), how many detached journal receivers to keep (KEEPRCVCNT), and how long to keep detached journal receivers (KEEPJRNRCV).

Regardless of how receiver delete management is configured, MIMIX reports that extra receivers eligible for deletion exist on the Receivers view of the Work with Journal Definitions display.

Also regardless of how receiver delete management is configured, MIMIX warns when a system has receivers eligible for deletion and the system auxiliary storage pool (ASP 1) is storage-constrained. When the storage used by ASP 1 exceeds the system ASP threshold warning policy for delete-eligible receivers, MIMIX sets the journal manager status on that system to *JRNRCVCNT. Users who are subscribed to events within the Assure UI portal will receive an email when this condition exists.

In configurations that use the Assure MIMIX IBM MQ feature, the value *YES also allows MIMIX to determine whether IBM MQ for IBM i has finished using receivers for the AMQAJRN journal before performing delete management.

Note: If more than one MIMIX installation uses the same journal, the journal manager for each installation can delete the journal regardless of whether the other installations are finished with it. If you have this scenario, you need to use the journal receiver delete management exit points to control deleting the journal receiver. For more information, see Working with journal receiver management user exit points.

Delete management of the source and target receivers occur independently from each other. MIMIX operations can be affected if you allow the system to handle delete management. The system may delete a journal receiver before MIMIX has completed its use. It is highly recommended that you configure the journal definitions to have MIMIX perform journal delete management. By default, the IBM i remote journal function does not allow a receiver to be deleted until it is sent from the local journal (source) to the remote journal (target). When MIMIX manages deletion, a remote journal receiver on the target system, and the corresponding local journal receiver on the source system, cannot be deleted until it is processed by the database reader (DBRDR) and the database apply (DBAPY) processes and it meets the other criteria defined in the journal definition.

Attention: If you need to delete journal receivers manually and MIMIX is managing receiver deletion, contact Support.