Interoperation when WebSphere Application Server application server is not clustered and IBM MQ queue manager is not clustered

Application servers running on WebSphere Application Server and queue managers running on IBM MQ can connect to each other when neither of them are clustered. However, this setup can be vulnerable to failure.

In this topic "application server" refers to an application server running on WebSphere Application Server and "queue manager" refers to a queue manager running on IBM MQ.

There are two topology options:

• The application server and the queue manager run on different hosts

• The application server and the queue manager run on the same host

The application server and the queue manager run on different hosts

The IBM MQ transport type for the connection is specified as "client". A client connection is used when the application server and queue manager are running on different hosts. This is a TCP/IP network connection used to communicate with the queue manager. A client connection is also known as "socket attach".

The following figure shows an application server and a queue manager running on different hosts.

Figure 1. No clustering: client mode attachment to queue manager

This topology is vulnerable because inter-operation ceases if any of the following conditions occurs:

• The application server fails.

• The host on which the application server is running fails.

• The queue manager fails.

• The host on which the queue manager is running fails.

We can improve availability for this topology using, for example, High Availability Cluster Multi-Processing HACMP™ to restart the failed component automatically.

The application server and the queue manager run on the same host

The transport type for the connection is specified as "bindings". A bindings connection is used when the application server and the queue manager are running on the same host. This is a cross-memory connection used to communicate with a queue manager. A bindings connection is also known as "call attach".

The following figure shows a application server and a queue manager running on the same host.

Figure 2. No clustering: bindings mode attachment to queue manager

The availability constraints for this topology are similar to the previous one. However, in some configurations bindings mode is faster and more processor efficient than client mode because the amount of processing is reduced.