In the case of service-controlled queues, the subsequent processing of messages sent by a program unit to a service-controlled queue is dealt with by the services of the application. openUTM merely ensures that the messages in the queues are saved. The application programs must themselves read the messages saved in these queues; if there are no messages in a queue, an application program unit can also wait for a message to arrive in a queue.
openUTM distinguishes between USER queues, TAC queues and temporary queues. The properties of these queues are described in sections "USER queues" to "Temporary queues". The associated MQ calls are listed in section "MQ calls ofthe KDCS interface". For more information on the lifetime of queues and messages in queues, refer to section "Lifetime of queues and queue messages".
Service-controlled queues offer new communication opportunities in a large number of cases; it is possible, for example, to use message queues to implement the following scenarios:
communication between independent services in an application
“pseudo dialogs” with remote transport system applications
parallel processing of database accesses in (read) transactions
sending of messages to UTM users (mailbox functionality)
sending of asynchronous messages to UPIC clients
sending of messages to queues in other applications (remote queues: see section "Service-controlled queues in distributed processing")
outputting of UTM messages at the UTM administration workstation WinAdmin or WebAdmin
implementation of user-controlled processing of asynchronous messages
serialization of program units (running in the dialog and asynchronously)
output of the data of other TLS blocks to the data station in the dialog
as global storage areas of unlimited size
The queues can be administered with the DADM call.