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Can the WebSphere MQ AMQAJRN Receiver size options attribute be set to MAXOPT3

Technote (FAQ)


Question

You want to know if the WebSphere MQ AMQAJRN Receiver size options attribute can be set to *MAXOPT3?

Answer

For MQ versions v8.0.0.4 and v7.1.0.7 and later(APAR SE61936):
If you specified RCVSIZOPT(*MAXOPT3), the system sends the warning message when the journal sequence number exceeds 18 446 644 000 000 000 000. If you use system change-journal management support (MNGRCV(*SYSTEM)) for the journal, the system attempts to change the journal and reset the sequence number one time. The message is sent only if the attempt is not successful.

Hence, if the CPI70E7 message is written to the journal message queue, then MQ will attempt to perform a CHGJRN JRNRCV(*GEN) SEQOPT(*RESET)

However, users should be aware of warning messages in QSYSOPR, such as CPF7019, which are indicative of the journal approaching maximum sequence numbers, and take appropriate measures.

Actions that will reset the journal sequence number include:
- CHGJRN JRNRCV(*GEN) SEQOPT(*RESET)
- An IPL of the system
- Vary on of the independent disk pool containing the AMQARN journal, if applicable.

Additionally, this APAR changes the default for the Queue Manager Journal Receiver size options (RCVSIZOPT) from MAXOPT2 to MAXOPT3 at IBM MQ V8. This will automatically be applied to
all queue managers created after this APAR has been applied.
Existing queue managers can also be modified to use MAXOPT3, if needed.

Previous versions of MQ will continue to utilize MAXOPT2.

MAXOPT3 will not be supported at pre-V8.0.0.4 and 7.1.0.7 releases.


MAXOPT3 provides a maximum sequence number of 18 446 744 073 709 551 600 vs 9 999 999 999 for MAXOPT2.

See APAR SE61936 for more information: http://www-01.ibm.com/support/docview.wss?uid=swg1SE61936

For MQ versions before 8.0.0.4 and 7.1.0.7:

WebSphere MQ Support does not recommend setting the Receiver Size options attribute to a value of *MAXOPT3. The current default setting is *MAXOPT2, which will cause the journal sequence number to be reset to a value of 1 after an IPL of the system. *MAXOPT3 is not recommended, since the product does not support sequence numbers greater than 9 999 999 999.

Excerpt from IBM i Information Center:
IBM i 7.1 Information Center > Systems management > Journal management > Local journal management > Managing journals > Swapping, deleting, and saving journals and receivers

"If you use system journal-receiver management for a journal and RCVSIZOPT(*MAXOPT3) is not specified, the sequence number for the journal is reset to 1 whenever you restart the system or vary on the independent disk pool containing the journal. When you restart the system or vary on an independent disk pool, the system performs the change journal operation for every journal on the system or disk pool that specifies system journal-receiver management. The operation that the system performs is equivalent to CHGJRN JRN(xxx) JRNRCV(*GEN) SEQOPT(*RESET). "


If you specify RCVSIZOPT(*MAXOPT1), RCVSIZOPT(*MAXOPT2), or RCVSIZOPT(*SYSDFT) for the journal to which you attached the receiver, the maximum sequence number is 9 999 999 999.

If you specify RCVSIZOPT(*MAXOPT3), the maximum sequence number is 18 446 744 073 709 551 600.

Related information

IBM i: Resetting the sequence number of journal entries

Product Alias/Synonym

IBMMQ WMQ MQ

Document information

More support for: WebSphere MQ
Usability

Software version: 7.0.1, 7.1, 8.0, 9.0

Operating system(s): IBM i

Software edition: Advanced

Reference #: 1625286

Modified date: 14 February 2017