Queue Manager Manual

1 Introduction to Queue
Management
46517 Tandem Computers Incorporated 1-1
Queue Manager provides capabilities for holding communications between processes
in a queue so that the processes can carry on other activities while Queue Manager
handles the interaction. This queuing function can be used with any application that
needs to separate an activity into multiple stages.
Figure 1-1 illustrates how two processes might interact without the presence of Queue
Manager. Process A initiates a request to Process B, which must be ready to receive
the request. A then waits while B acquires the resources necessary to respond to the
request. Finally, B responds. In this configuration, A and B are operating in a tightly
coupled mode. Neither entity can continue processing without a response from the
other.
Figure 1-1. Process Interaction without Queue Manager
Process A Process B
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In Figure 1-2, Queue Manager allows the processes to interact without interruption to
ongoing work such as data collection. Process A initiates a request to Process B by
submitting it to Queue Manager. (Process A also asks Queue Manager to send a
notification when B responds.) B has asked to be notified when A initiates a request,
so Queue Manager notifies B that a communication is waiting. B retrieves the request,
processes it, and forwards a response to the Queue Manager. Queue Manager notifies
A that the response has arrived. Process A retrieves the response to complete the
interaction.
Figure 1-2. Process Interaction with Queue Manager
Process A
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Process BQ Manager
Request
Notification/Request
Retrieval
Notification/Response
Retrieval
Response