openUTM provides the LPAP bundle function for the OSI TP and the LU6.1 protocols.
LPAP bundles allow load distribution and the use of alternative connections to a partner application. If a UTM application has to exchange a very large number of messages with a partner application then load distribution may be improved by starting multiple instances of the partner application and distributing the messages across the individual instances. In an LPAP bundle, openUTM is responsible for distributing the messages to the partner application instances. An LPAP bundle consists of a master LPAP and multiple slave LPAPs.
The slave LPAPs are assigned to the master LPAP on generation. In normal circumstances, the physical connections (CONs) of the individual slave LPAPs address different partner applications.
Operating an application
To allow openUTM to distribute the messages to the slave LPAPs, you address the messages to the master LPAP in the program units.
openUTM distributes these messages to the slave LPAPs in sequence. The system always attempts to find a slave LPAP via which the message can also be sent, i.e. to which a connection is established and for which, for instance, the queue level has not yet been exceeded.
For more details on this, refer to the description of the APRO call on "APRO Address job-receiving service".
Administration
The "Master LPAP" and "Slave LPAP" properties are displayed via the administration interface.
All the slave LPAPs are displayed for a master LPAP and the master LPAP is displayed for a slave LPAP.
Using the administration facilities, you can set the status of master LPAPs to ON or OFF. If you change the status of a Master LPAP, this causes the status to be changed accordingly on all slave LPAPs.