This topic describes the migration of a single-node environment
from the embedded messaging in WebSphere Application Server Version 5 to the
default messaging provider in WebSphere Application Server version 6.
Before you begin
Before migrating a WebSphere Application Server Version 5 node, you
need to stop Version 5 JMS applications using the JMS queues that are to be
migrated.
- Stop all message-producing JMS applications in the WebSphere Application
Server Version 5 environment. For example, you can use the administrative
console to stop the applications, as described in Starting and stopping applications.
- Allow all message-consuming JMS applications (including those consuming
publications as a result of durable subscriptions) to continue until all the
JMS queues are drained, then stop those applications.
Why and when to perform this task
This topic provides the main steps, which are based on the general
considerations given in General considerations for migrating from Version 5 embedded messaging.
The
main consideration is that when migrating a WebSphere Application Server version
5 node to version 6, you do not need to make any changes to JMS applications;
they can continue to use their same deployment and installation, and their
same configurations of Version 5 JMS resources (with one exception below).
Note: To
make reading easier in this topic, the abbreviation "Version 5" is sometimes
used to refer to "WebSphere Application Server Version 5" and "version
6" is used to refer to "WebSphere Application Server version 6". For
example, "Version 5 JMS resources" refers to JMS resources provided by
WebSphere Application Server Version 5.
Consider the basic single-node
scenario shown, before migration, in the following figure
Figure 1.
- The JMS application uses JNDI to look up the JMS resources in the WebSphere
Application Server name space.
- The JMS resources in this example are a JMS queue connection factory (shown
as JMS QCF) and a JMS queue (shown as JMS Q).
- WebSphere Application Server Version 5 embedded messaging uses WebSphere
MQ technology, and is implemented through a JMS server that runs as the jmsserver
service of the application server. The JMS application uses WebSphere MQ client
protocols to communicate with the JMS server.
To migrate a single-node WebSphere Application Server environment
from Version 5 embedded messaging to the version 6 default messaging provider,
complete the following steps:
Steps for this task
- Migrate the WebSphere Application Server node to Version 6. Use the procedure described in Migrating product configurations. The Version 5 embedded messaging JMS resources have been migrated
to Version 5 default messaging JMS resources.
- If any V5 default messaging JMS topic connection factory has the
Port property set to DIRECT, you must change it to QUEUED before use
with the version 6 default messaging provider. For example, after migrating
the node use the version 6 WebSphere administrative console to complete the
following steps:
- Display the Version 5 default messaging JMS topic connection
factory Click jms_tcf_name.
- For the Port field, select the QUEUED
option
- Click OK.
- Save any changes to the master configuration.
After migrating the node, the basic single-node scenario becomes
as shown in the following figure
Figure 2.
- The JMS application can continue to access the Version 5 JMS resources,
which are now managed as V5 default messaging JMS resources implemented by
the WebSphere Application Server version 6 default messaging provider.
- The JMS application communicates with the Version 5 JMS resources through
the WebSphere MQ client link and the messaging engine. This is invisible
to the JMS application.
- The JMS resources, a JMS queue connection factory, shown as JMS QCF(V5),
and a JMS queue, shown as JMS Q(V5), are managed as Version 5 default messaging
JMS resources.
- The new bus queue, shown as Bus Q, is managed as a resource of the service
integration bus. Messages for JMS Q(V5) are stored and processed by the message
point for the associated bus destination, a queue point shown as BusQ@ME.
- The WebSphere MQ client link presents itself as a queue manager
and transforms between the WebSphere MQ client protocols used by Version 5
JMS applications and the WebSphere Application Server version 6 protocols
used by messaging engines.
You should replace the Version 5 default messaging JMS resources
with equivalent version 6 default messaging provider JMS resources as soon
as is conveniently possible (after all JMS applications using those resources
have been moved onto WebSphere Application Server version 6).
You should
define any new JMS resources as version 6 resources; for example, as described
in Configuring resources for the default messaging provider.