Real-life accounts of successful and failed SOA projects discussed first-hand by those that experienced the project lifecycles and have a story to tell. These veteran practitioners will provide advice and insights regarding challenges, pitfalls, proven practices, and general project information that demonstrates the intricacies of implementing and governing service-oriented solutions in the real world.

I will be presenting the first session in this track on Using a Service Bus to Connect the Supply Chain. If you have any topics or questions in advance that you think I should address, please post them in the comments. Hope to meet you in Berlin.

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SELECT aq.name
,      aq.queue_table
,      aq.queue_type
,      v$aq.* 
FROM   v$aq
,      all_queues aq
WHERE  aq.qid = v$aq.qid
-- use if looking for ESB AQ: and    aq.queue_table = 'ESB_JAVA_DEFERRED';
;

The query will result in something like:

It contains the following metrics:

• Waiting – Number of waiting message;
• Ready – Number of messages with status ready;
• Expired – Number of expired messages;
• Total Wait – Total waiting time per queue;
• Average Wait – Average waiting time per queue.

A describtion of the AQ and Streams views can be found here.

Queue compatibility

When creating the ORAESB schema (in version 10.1.3.3) using the script $ORACLE_HOME/integration/esb/sql/oracle/create_esb_topics.sql, the queues are created with 8.1 compatibility. This is solved in 10.1.3.4. To alter this find the statement

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dbms_aqadm.create_queue_table
    ( Queue_table => qtablename
    , Queue_payload_type => 'SYS.AQ$_JMS_TEXT_MESSAGE'
    , multiple_consumers => true
    , compatible => '8.1'
    );

and change this to:

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dbms_aqadm.create_queue_table
    ( Queue_table => qtablename
    , Queue_payload_type => 'SYS.AQ$_JMS_TEXT_MESSAGE'
    , multiple_consumers => true
    , compatible => '10.2'
    );

if you already created the queues, use this statement:

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dbms_aqadm.migrate_queue_table
    ( queue_table => 'ESB_JAVA_DEFERRED'
    , compatible => '10.2'
    );

If you’re not sure check the compatibility with this query:

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SELECT queue_table
,      compatible
,      recipients
FROM   dba_QUEUE_tables
WHERE  owner = 'ORAESB'
;

Streams pool size

Verify the current stream_pool_size using the following query:

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SELECT component
,      current_size/1024/1024 "CURRENT_SIZE"
,      min_size/1024/1024 "MIN_SIZE"
,      user_specified_size/1024/1024 "USER_SPECIFIED_SIZE"
,      last_oper_type "TYPE" 
FROM   v$sga_dynamic_components
;

look for the streams pool. There are several Metalink notes on this setting (including 316889.1, 102926.1 and 335516.1). The latter has a general recommandetion per RDBMS version:

• 11g: set STREAMS_POOL_SIZE to be greater or equal to 100 MB;
• 10gR2: set SGA_TARGET > 0 and STREAMS_POOL_SIZE=0 to enable autotuning of the Streams pool;
• 10gR1: use the STREAMS_POOL_SIZE init.ora parameter to configure the Streams memory allocation;

And of course you could use V$STREAMS_POOL_ADVICE to get advice for your specific situation.

Upgrade the JDK

A described here upgrading the JDK can also give a performance boost.

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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

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

Find the queue you want to monitor.

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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