The WebSphere MQ Everyplace queue manager allows WebSphere MQ Everyplace to support a variety of network configurations. It provides:
In WebSphere MQ Everyplace, you can only have one queue manager active on a single Java virtual machine (JVM), or in a single native application process at any one time. To have multiple queue managers on a machine, you require either multiple JVM or multiple native application processes.
Queue managers are identified by a globally unique name and an ASCII
character string of unlimited length, excluding any of the following
characters:
{ } [ ] # ( ) : ; , ' " =
This restriction is not enforced by WebSphere MQ Everyplace or WebSphere MQ,
but duplicate queue manager names may cause messages to be delivered to the
wrong queue manager. For interoperability, we recommend that you limit
the maximum name length to 48 characters. The file system that you are
using may also restrict the name length.
You can configure queue managers with or without local queueing. All queue managers support synchronous messaging operations. A queue manager with local queueing also supports asynchronous message delivery. Asynchronous message delivery and synchronous message delivery have very different characteristics and consequences:
Chapter 6, Message delivery, of the WebSphere MQ Everyplace Application Programming Guide provides detailed information on synchronous and asynchronous messaging.
The queue manager runs in an environment established by WebSphere MQ Everyplace, before the queue manager is loaded. The queue manager stores its configuration information in its registry. The registry provides more information on this. The queues themselves (containing messages) are stored in queue stores.
You can configure the WebSphere MQ Everyplace environment using the API, utilities shipped with WebSphere MQ Everyplace, or management tools such as MQe_Explorer. These methods can capture the environment parameters in an initialization file, but this is optional. Chapter 5, Queue manager operations, of the WebSphere MQ Everyplace Application Programming Guide provides information on how to configure queue managers. The WebSphere MQ Everyplace Configuration Guide provides information on configuring queue managers using the MQe_Explorer tool.
You can configure a queue manager with WebSphere MQ bridge capabilities. This is called a gateway and, in Java, it exchanges messages with WebSphere MQ host and distributed products. The C codebase uses a device queue manager only. Chapter 7, Interoperability with other messaging systems of the WebSphere MQ Everyplace Application Programming Guide provides detailed information on how to configure the bridge.
Queue managers support messaging operations and manage queues. Applications access messages through the services of the queue manager using methods such as:
Many of these operations take a filter as one of their parameters. A filter matches an element for equality and any parts of the message can be used for selective retrieval. Most method calls also include an attribute to be used in the encoding or decoding of a message. Chapter 4, Messaging, of the WebSphere MQ Everyplace Application Programming Guide provides detailed information on messaging operations.