Negative Valuues For Metric Average Age Of Messages Per Persistent Queue (Doc ID 3052150.1)

Last updated on FEBRUARY 13, 2025

Applies to:

Symptoms

Negative valuues for Metric Average age of messages per persistent queue

Clarification from below explanation from RDBMS team

For weighted_avg_msg_age : It is negative only in one condition if enqueued_msgs is less than dequeued_msgs and avg_msg_age is also 0. Therefore, SUM (avg_msg_age * (enqueued_msgs - dequeued_msgs)) is +ve and DECODE(SUM(enqueued_msgs - dequeued_msgs), 0, -1, (SUM(enqueued_msgs - dequeued_msgs)) is -ve and there division also comes negative. So if we add a condition like enqueued_msgs must be greater or equals to dequeued_msgs than the above query should work fine.

For first_message_age : It is negative because oldest_msg_enqtm column value is null. Not sure from where oldest_msg_enqtm is getting populated.
Kindly asked DB team about enqueued_msgs, dequeued_msgs, avg_msg_age in GV$PERSISTENT_QUEUES, how it is calculated and why dequeued_msgs is greater than enqueued_msgs if it is expected then why avg_msg_age is coming as 0 for such case.

Cause

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