Expand Management Programming Manual

SECTION 3
COMMUNICATING WITH THE EXPAND MANAGER PROCESS
This section describes how a management application sends com-
mands to and receives responses from the EXPAND subsystem.
Obtaining event messages from the EXPAND subsystem is described
in Section 8, "Event Management."
COMMUNICATING THROUGH SCP
To manage the EXPAND subsystem, an application communicates
with the EXPAND manager process. However, to communicate with
this process, an application opens and sends requests to a
process called the Subsystem Control Point (SCP). Communication
between an application and SCP is described in the Communications
Management Programming Manual , and it consists of the following
steps:
1. The application opens the SCP process.
2. The application sends an SPI-formatted request (an EXPAND
command) to SCP. A token in the command tells SCP that the
request is for the EXPAND subsystem.
3. SCP checks whether or not the EXPAND manager process is open.
If it is not, SCP opens it.
4. SCP checks whether or not the versions of the EXPAND manager
process and the application are compatible, and it performs
security validation on the request.
5. If all is well, SCP forwards the request to the EXPAND
manager process.
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