IBM GC34-5557-00 Webcam User Manual


 
Time-Independent Applications
With message queuing, the exchange of messages between the sending and
receiving programs is time independent. This means that the sending and
receiving applications are decoupled; the sender can continue processing
without having to wait for the receiver to acknowledge receipt of the message.
In fact, the target application does not even have to be running when the
message is sent. It can retrieve the message when it starts running.
Message-Driven Processing
On arrival on a queue, messages can automatically start an application by
using a technique known as triggering. If necessary, the application can be
stopped when the message or messages have been processed.
Messages and Queues
Messages and queues are the basic components of a message queuing system.
What is a Message?
A message is a string of bytes that has meaning to the applications that use it.
Messages are used to transfer information from one application to another (or
to different parts of the same application). The applications can be running on
the same platform, or on different platforms.
MQSeries messages have two parts; the application data and a message
descriptor. The content and structure of the application data are defined by the
application programs that use the data. The message descriptor identifies the
message and contains control information, such as the type of message and
the priority assigned to it by the sending application.
Message Queuing
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MQSeries for AS/400, V5.1 Quick Beginnings