Wednesday Dec 12, 2012

JMS Step 6 - How to Set Up an AQ JMS (Advanced Queueing JMS) for SOA Purposes

JMS Step 6 - How to Set Up an AQ JMS (Advanced Queueing JMS) for SOA Purposes

This post continues the series of JMS articles which demonstrate how to use JMS queues in a SOA context. The previous posts were:

  1. JMS Step 1 - How to Create a Simple JMS Queue in Weblogic Server 11g
  2. JMS Step 2 - Using the QueueSend.java Sample Program to Send a Message to a JMS Queue
  3. JMS Step 3 - Using the QueueReceive.java Sample Program to Read a Message from a JMS Queue
  4. JMS Step 4 - How to Create an 11g BPEL Process Which Writes a Message Based on an XML Schema to a JMS Queue
  5. JMS Step 5 - How to Create an 11g BPEL Process Which Reads a Message Based on an XML Schema from a JMS Queue

This example leads you through the creation of an Oracle database Advanced Queue and the related WebLogic server objects in order to use AQ JMS in connection with a SOA composite. If you have not already done so, I recommend you look at the previous posts in this series, as they include steps which this example builds upon.

The following examples will demonstrate how to write and read from the queue from a SOA process.

1. Recap and Prerequisites

In the previous examples, we created a JMS Queue, a Connection Factory and a Connection Pool in the WebLogic Server Console. Then we wrote and deployed BPEL composites, which enqueued and dequeued a simple XML payload.

AQ JMS allows you to interoperate with database Advanced Queueing via JMS in WebLogic server and therefore take advantage of database features, while maintaining compliance with the JMS architecture. AQ JMS uses the WebLogic JMS Foreign Server framework. A full description of this functionality can be found in the following Oracle documentation

Oracle® Fusion Middleware Configuring and Managing JMS for Oracle WebLogic Server
11g Release 1 (10.3.6)
Part Number E13738-06
7. Interoperating with Oracle AQ JMS
http://docs.oracle.com/cd/E23943_01/web.1111/e13738/aq_jms.htm#CJACBCEJ

For easier reference, this sample will use the same names for the objects as in the above document, except for the name of the database user, as it is possible that this user already exists in your database. We will create the following objects

Database Objects

Name

Type

AQJMSUSER

Database User

MyQueueTable

Advanced Queue (AQ) Table

UserQueue

Advanced Queue

WebLogic Server Objects

Object Name

Type

JNDI Name

aqjmsuserDataSource

Data Source

jdbc/aqjmsuserDataSource

AqJmsModule

JMS System Module

AqJmsForeignServer

JMS Foreign Server

AqJmsForeignServerConnectionFactory

JMS Foreign Server Connection Factory

AqJmsForeignServerConnectionFactory

AqJmsForeignDestination

AQ JMS Foreign Destination

queue/USERQUEUE

eis/aqjms/UserQueue

Connection Pool

eis/aqjms/UserQueue

2. Create a Database User and Advanced Queue

The following steps can be executed in the database client of your choice, e.g. JDeveloper or SQL Developer. The examples below use SQL*Plus.

Log in to the database as a DBA user, for example SYSTEM or SYS. Create the AQJMSUSER user and grant privileges to enable the user to create AQ objects.

Create Database User and Grant AQ Privileges

sqlplus system/password as SYSDBA
	      
GRANT connect, resource TO aqjmsuser IDENTIFIED BY aqjmsuser;
GRANT aq_user_role TO aqjmsuser;
GRANT execute ON sys.dbms_aqadm TO aqjmsuser;
GRANT execute ON sys.dbms_aq TO aqjmsuser;
GRANT execute ON sys.dbms_aqin TO aqjmsuser;
GRANT execute ON sys.dbms_aqjms TO aqjmsuser;

Create the Queue Table and Advanced Queue and Start the AQ

The following commands are executed as the aqjmsuser database user.

Create the Queue Table

connect aqjmsuser/aqjmsuser;
BEGIN
dbms_aqadm.create_queue_table (
queue_table => 'myQueueTable',
queue_payload_type => 'sys.aq$_jms_text_message',
multiple_consumers => false
);
END;
/

Create the AQ

BEGIN
dbms_aqadm.create_queue (
queue_name => 'userQueue',
queue_table => 'myQueueTable'
);
END;
/

Start the AQ

BEGIN
dbms_aqadm.start_queue (
queue_name => 'userQueue');
END;
/

The above commands can be executed in a single PL/SQL block, but are shown as separate blocks in this example for ease of reference.

You can verify the queue by executing the SQL command

SELECT object_name, object_type FROM user_objects;

which should display the following objects:

OBJECT_NAME                        OBJECT_TYPE
------------------------------ ------------------- 
SYS_C0056513                       INDEX 
SYS_LOB0000170822C00041$$          LOB 
SYS_LOB0000170822C00040$$          LOB 
SYS_LOB0000170822C00037$$          LOB 
AQ$_MYQUEUETABLE_T                 INDEX 
AQ$_MYQUEUETABLE_I                 INDEX 
AQ$_MYQUEUETABLE_E                 QUEUE 
AQ$_MYQUEUETABLE_F                 VIEW 
AQ$MYQUEUETABLE                    VIEW 
MYQUEUETABLE                       TABLE 
USERQUEUE                          QUEUE

Similarly, you can view the objects in JDeveloper via a Database Connection to the AQJMSUSER.

3. Configure WebLogic Server and Add JMS Objects

All these steps are executed from the WebLogic Server Administration Console. Log in as the webLogic user.

Configure a WebLogic Data Source

The data source is required for the database connection to the AQ created above.

Navigate to domain > Services > Data Sources and press New then Generic Data Source.

Use the values:
Name:
aqjmsuserDataSource
JNDI Name:
jdbc/aqjmsuserDataSource

Database type: Oracle

Database Driver: *Oracle’ Driver (Thin XA) for Instance connections; Versions:9.0.1 and later

Connection Properties: Enter the connection information to the database containing the AQ created above and enter aqjmsuser for the User Name and Password.

Press Test Configuration to verify the connection details and press Next.

Target the data source to the soa server.

The data source will be displayed in the list.

It is a good idea to test the data source at this stage. Click on aqjmsuserDataSource, select Monitoring > Testing > soa_server1 and press Test Data Source. The result is displayed at the top of the page.

Configure a JMS System Module

The JMS system module is required to host the JMS foreign server for AQ resources.

Navigate to Services > Messaging > JMS Modules and select New.

Use the values:

Name: AqJmsModule

(Leave Descriptor File Name and Location in Domain empty.)
Target: soa_server1

Click Finish. The other resources will be created in separate steps.

The module will be displayed in the list.

 

Configure a JMS Foreign Server

A foreign server is required in order to reference a 3rd-party JMS provider, in this case the database AQ, within a local WebLogic server JNDI tree.

Navigate to Services > Messaging > JMS Modules and select (click on) AqJmsModule to configure it.

Under Summary of Resources, select New then Foreign Server.

Name: AqJmsForeignServer
Targets: The foreign server is targeted automatically to soa_server1, based on the JMS module’s target.

Press Finish to create the foreign server.

The foreign server resource will be listed in the Summary of Resources for the AqJmsModule, but needs additional configuration steps.

Click on AqJmsForeignServer and select Configuration > General to complete the configuration:

JNDI Initial Context Factory: oracle.jms.AQjmsInitialContextFactory
JNDI Connection URL: <empty>
JNDI Properties Credential:<empty>
Confirm JNDI Properties Credential: <empty>
JNDI Properties:
datasource=jdbc/aqjmsuserDataSource
This is an important property. It is the JNDI name of the data source created above, which points to the AQ schema in the database and must be entered as a name=value pair, as in this example, e.g. datasource=jdbc/aqjmsuserDataSource, including the “datasource=” property name.
Default Targeting Enabled: Leave this value checked.

Press Save to save the configuration.

At this point it is a good idea to verify that the data source was written correctly to the config file. In a terminal window, navigate to $MIDDLEWARE_HOME/user_projects/domains/soa_domain/config/jms  and open the file aqjmsmodule-jms.xml . The foreign server configuration should contain the datasource name-value pair, as follows:

 
<foreign-server name="AqJmsForeignServer">
        <default-targeting-enabled>true</default-targeting-enabled>
        <initial-context-factory>oracle.jms.AQjmsInitialContextFactory</initial-context-factory>
        <jndi-property>
          <key> datasource </key>
          <value> jdbc/aqjmsuserDataSource </value>
        </jndi-property>
  </foreign-server>
</weblogic-jms>

Configure a JMS Foreign Server Connection Factory

When creating the foreign server connection factory, you enter local and remote JNDI names. The name of the connection factory itself and the local JNDI name are arbitrary, but the remote JNDI name must match a specific format, depending on the type of queue or topic to be accessed in the database. This is very important and if the incorrect value is used, the connection to the queue will not be established and the error messages you get will not immediately reflect the cause of the error. The formats required (Remote JNDI names for AQ JMS Connection Factories) are described in the section Configure AQ Destinations  of the Oracle® Fusion Middleware Configuring and Managing JMS for Oracle WebLogic Server document mentioned earlier.

In this example, the remote JNDI name used is   XAQueueConnectionFactory  because it matches the AQ and data source created earlier, i.e. thin with AQ.

Navigate to JMS Modules > AqJmsModule > AqJmsForeignServer > Connection Factories then New.
Name:
AqJmsForeignServerConnectionFactory

Local JNDI Name: AqJmsForeignServerConnectionFactory

Note: this local JNDI name is the JNDI name which your client application, e.g. a later BPEL process, will use to access this connection factory.

Remote JNDI Name: XAQueueConnectionFactory
Press OK to save the configuration.

Configure an AQ JMS Foreign Server Destination

A foreign server destination maps the JNDI name on the foreign JNDI provider to the respective local JNDI name, allowing the foreign JNDI name to be accessed via the local server. As with the foreign server connection factory, the local JNDI name is arbitrary (but must be unique), but the remote JNDI name must conform to a specific format defined in the section Configure AQ Destinations  of the Oracle® Fusion Middleware Configuring and Managing JMS for Oracle WebLogic Server document mentioned earlier.

In our example, the remote JNDI name is Queues/USERQUEUE , because it references a queue (as opposed to a topic) with the name USERQUEUE. We will name the local JNDI name queue/USERQUEUE, which is a little confusing (note the missing “s” in “queue), but conforms better to the JNDI nomenclature in our SOA server and also allows us to differentiate between the local and remote names for demonstration purposes.

Navigate to JMS Modules > AqJmsModule > AqJmsForeignServer > Destinations and select New.
Name:
AqJmsForeignDestination

Local JNDI Name: queue/USERQUEUE

Remote JNDI Name:Queues/USERQUEUE

After saving the foreign destination configuration, this completes the JMS part of the configuration. We still need to configure the JMS adapter in order to be able to access the queue from a BPEL processt.

4. Create a JMS Adapter Connection Pool in Weblogic Server

Create the Connection Pool

Access to the AQ JMS queue from a BPEL or other SOA process in our example is done via a JMS adapter. To enable this, the JmsAdapter in WebLogic server needs to be configured to have a connection pool which points to the local connection factory JNDI name which was created earlier.

Navigate to Deployments > Next and select (click on) the JmsAdapter.


Select Configuration > Outbound Connection Pools and
New.

Check the radio button for oracle.tip.adapter.jms.IJmsConnectionFactory and press Next.

JNDI Name: eis/aqjms/UserQueue

Press Finish

Expand oracle.tip.adapter.jms.IJmsConnectionFactory and click on eis/aqjms/UserQueue to configure it.


The ConnectionFactoryLocation must point to the foreign server’s local connection factory name created earlier. In our example, this is
AqJmsForeignServerConnectionFactory . As a reminder, this connection factory is located under JMS Modules > AqJmsModule > AqJmsForeignServer > Connection Factories and the value needed here is under Local JNDI Name.

Enter AqJmsForeignServerConnectionFactory  into the Property Value field for ConnectionFactoryLocation. You must then press Return/Enter then Save for the value to be accepted.


If your WebLogic server is running in Development mode, you should see the message that the changes have been activated and the deployment plan successfully updated. If not, then you will manually need to activate the changes in the WebLogic server console.

Although the changes have been activated, the JmsAdapter needs to be redeployed in order for the changes to become effective. This should be confirmed by the message
Remember to update your deployment to reflect the new plan when you are finished with your changes.

Redeploy the JmsAdapter

Navigate back to the Deployments screen, either by selecting it in the left-hand navigation tree or by selecting the “Summary of Deployments” link in the breadcrumbs list at the top of the screen. Then select the checkbox next to JmsAdapter and press the Update button.

On the Update Application Assistant page, select “Redeploy this application using the following deployment files” and press Finish.

After a few seconds you should get the message that the selected deployments were updated.

The JMS adapter configuration is complete and it can now be used to access the AQ JMS queue. You can verify that the JNDI name was created correctly, by navigating to Environment > Servers > soa_server1 and View JNDI Tree. Then scroll down in the JNDI Tree Structure to eis and select aqjms.


This concludes the sample.

In the following post, I will show you how to create a BPEL process which sends a message to this advanced queue via JMS.

Best regards
John-Brown Evans
Oracle Technology Proactive Support Delivery

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This is the official blog of the SOA Proactive Support Team. Here we will provide information on our activities, publications, product related information and more. Additionally we look forward to your feedback to improve what we do.

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