web server - Borland Technical Publications

OpenJMS
Even though OpenJMS can be used in a standalone mode where it is the only service
in the partition, there are some advantages to using OpenJMS as an in-process
service:
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It helps avoid the two-phase commit (2PC), and hence the performance cost and
deployment complexity associated with it. This involves JDBC connection sharing
among different components in the partition that access the database. It can be
achieved by making OpenJMS persist messages in the same database as the one
in which application data is stored. This configuration where 2PC can be avoided is
possible only when OpenJMS is accessed through its embedded or RMI connector
inside the BES partition. See “Configuring Datasource to Achieve 2PC Optimization”
on page 232 for details.
Since all the components are centralized in a single virtual machine, you can avoid
the cost of TCP/IP. The JMS client library calls an in-process JMS service using
regular Java call and vice versa.
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Since VBJ provides local call optimizations, the application won't need to have two
types of connectors. It can use only the RMI connector irrespective of client location
with respect to the JMS server.
You can find the OpenJMS product documentation in the /jms/openjms/
docs directory.
Configuring JNDI objects for OpenJMS
Note
Since each partition in BES can host an instance of OpenJMS, there is a dedicated
configuration file, openjms.xml, for each partition. The openjms.xml file contains
information about various OpenJMS connectors and JNDI objects that the instance
hosts.
BES does not support the administration GUI in OpenJMS. You can create and delete
queues for OpenJMS by editing the openjms.xml file.
To add new Queues, Topics or Connection Factories for OpenJMS, you must modify
its configuration file, openjms.xml. To access this file:
1 Select the relevant partition in the left pane.
2 Right-click on the OpenJMS service in the left pane.
3 Select Properties from the drop-down menu.
4 Click on the openjms.xml tab in the right pane to bring it forward.
5 Edit the file to add the JNDI objects.
See the OpenJMS documentation in the /jms/openjms/docs directory
for more details on this file.
The code sample below shows you how to add a Queue and a Topic connection
factory.
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You can add any number of factories as necessary for your application.
Make sure that each object you add has a unique name so as to avoid being
overwritten in JNDI. The name has to be unique among multiple instances.
You must have at least one TopicConnectionFactory and one
QueueConnectionFactory in the embedded scheme.
If you do not specify a port for the connector, the default port will be used. Refer to
the OpenJMS documentation for details located in /jms/openjms/docs.
230 BES Developer’s Guide