Network Deployment (Distributed operating systems), v8.0 > Reference > Developer best practices
WebSphere MQ server: Restrictions with mixed level cells and clusters
If you are using a WebSphere MQ server with cells or clusters that include more than one version of WAS, you might need to be aware of the application server versions when you deploy applications that communicate with WebSphere MQ queues.
With a WebSphere MQ server, applications reference service integration destinations that have queue points or mediation points set as WebSphere MQ queues. These service integration destinations are available to v6.1 and later versions of WAS, but are not available to v6.0 and earlier versions of WAS, which do not support them. There are some restrictions on the deployment of an application that references a service integration destination that is not available to earlier versions of WAS.
Take the following example situation:
- You define a service integration destination destination_x that has a queue point set as a WebSphere MQ queue.
- Destination_x is in bus bus_y.
- Destination_x is visible in all application servers at Version 6.1 or later, but it is not visible in application servers at Version 6.0 or earlier.
- You want to deploy an application appl_z that references destination_x.
In this example situation, the following restrictions apply:
- We must not deploy appl_z on any application server that is a member of bus_y unless that application server is at v6.1 or later.
- We must not deploy appl_z on any WAS cluster that is a member of bus_y unless every application server in that cluster is at Version 6.1 or later.
- We can deploy appl_z on any application server or cluster that is not a member of bus_y. However, if any of the application servers in that cell are at v6.0 or earlier, the following additional rules apply:
- We must define a target group containing messaging engines in bus_y that always run in application servers at v6.1 or later.
- Configure the JMS connection factory (if any) used by appl_z to select that target group with Target significance Required. Configure the JMS activation specification (if any) for appl_z to select that target group with Target significance Required