Why do the JMS dbms_aqadm.add_subscriber and dbms_aqadm.remove_subscriber calls sometimes hang when there are concurrent enqueues or dequeues happening on the same queue to which these calls are issued?
Answer / munnu
Add_subscriber and remove_subscriber are administrative operations on a queue. Though AQ does not prevent applications from issuing administrative and operational calls concurrently, they are executed serially. Both add_subscriber and remove_subscriber will block until pending transactions that have enqueued or dequeued messages commit and release the resources they hold. It is expected that adding and removing subscribers will not be a frequent event. It will mostly be part of the setup for the application. The behavior you observe will be acceptable in most cases. The solution is to try to isolate the calls to add_subscriber and remove_subscriber at the setup or cleanup phase when there are no other operations happening on the queue. That will make sure that they will not stay blocked waiting for operational calls to release resources.
Is This Answer Correct ? | 0 Yes | 0 No |
For JMS-enabled application, what are the core JMS-related objects required?
What is a remote jms provider?
Mention different types of messages available in JMS API?
What are Messaging Domains?
What is jms module in weblogic?
What is jms publisher?
What is jms and how it works?
How do I start wls and configure jms?
what is Java Message Service (JMS)?
What does kms mean?
What is the difference between pub/sub and Point to Point i.e. p2p. ?
What is a queued message?