Tag Archives: JMS

Will AQ enqueue and dequeue messages

Whether or not your Oracle Advanced Queue (AQ) will enqueue and dequeue messages can be determined with a simple query:

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SELECT name
,      queue_table
,      enqueue_enabled
,      dequeue_enabled
,      max_retries
,      retry_delay
FROM   user_queues
;

The query example is based on user_queues and in that case it has to be performed as the owner of the queue. The result wil be something like:

AQ enqueu dequeue

AQ enqueu dequeue

What is in the (Oracle Advanced) queue? – Monitoring AQ

As a quick follow up on the previous post… If you are using a JMS queue with Oracle´s Advanced Queueing or Streams (as they have been extended to) the previously described tool can´t help you out. You need something else for monitoring AQ.

For this case a blog by a former colleague helps us out. This approach to monitoring AQ boils down to…

Find the queue you want to monitor AQ.

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SELECT owner
,      queue_table
,      TYPE
,      user_comment
FROM   all_queue_tables

Perform a query.

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SELECT msgid
,      enq_time
,      enq_uid
,      qt.user_data.text_vc
FROM   my_queue_table qt  --alter the table name
WHERE  q_name = 'MY_QUEUE' --alter the queue name

What is in the queue?

Async queue

Async queue

One of our customers asked me exactly this question. They have an  Oracle ESB and it seemed that it could not handle all incoming requests. With the queues being a decoupling point between the incoming requests and the related transactions to the back office systems, its size can be an indication of just how busy the system is.

As I couldn’t find the answer using the Oracle Enterprise Manager Oracle Enterprise Manager and its MBeans, I started to look on the web for a tool. The tool I found and started to use was HermesJMS. This helps you interact with JMS providers making it easy to browse or search queues and topics, copy messages around and delete them.

HermesJMS screenshot

HermesJMS screenshot

The HermesJMS requires Java 1.6. It has a clear installation guide installation guide and it is tested for multiple JMS providers. Besides the guide we needed for the Oracle AS there is also another blog describing the install and use of HermesJMS.

Using HermesJMS we were able to answer this customers question.