OSI/MHS Management Programming Manual

OSI/MHS Management Programming Manual—424824-001
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Communicating with the OSI/MHS
Processes
A management application communicates with OSI/MHS through the Subsystem
Programmatic Interface (SPI). It retrieves event messages from OSI/MHS through the
Event Management Service (EMS). This section covers the following topics:
•
Communicating through SCP
•
SPI segmentation
•
Running the OSI/MHS subsystem processes
•
Running an EMS consumer distributor
Communicating Through SCP
To manage the OSI/MHS subsystem, your application sends commands to be performed
by the MHS manager. To communicate with this process, the application opens a
process called the Subsystem Control Point (SCP) and sends the OSI/MHS commands
to it. SCP acts as an intermediary between management applications and subsystems
such as OSI/MHS. It forwards some commands to the subsystem processes and
performs a few commands itself.
The SPI Common Extensions Manual describes how to run the SCP process and
describes, in detail, communication through SCP. In brief, this communication consists
of the following steps:
1. The application opens the SCP process.
2. The application sends an SPI-formatted request (an OSI/MHS command) to SCP. A
token in the command indicates to SCP that the request is for the OSI/MHS
subsystem.
3. SCP checks whether the MHS manager that is to receive the command is open. If it
is not, SCP opens it and, if this is the first command sent to this MHS manager, it
gets the version of the process.
4. SCP performs security validation on the request, and checks whether the version of
the OSI/MHS subsystem’s DSM interface is compatible with the application.
5. If all is well, SCP forwards the request to the appropriate MHS manager.
6. The MHS manager then performs the requested action, formats a response, and
sends the response to SCP.
7. SCP forwards the response to the application.
8. Before terminating, the application closes the SCP process.