TS/MP Management Programming Manual (G06.24+, H06.03+)

TS/MP Management Programming
NonStop TS/MP Management Programming Manual—540082-001
2-6
Design Considerations
Figure 2-1 on page 2-6 illustrates the commands sent and the responses received
when configuring a Pathway subsystem.
For a more detailed description of how to build command messages and decode
responses, see Section 3, SPI Programming Considerations. Details on the SPI
procedures and their use with various languages are available in the SPI Programming
Manual.
Design Considerations
Consider these points when designing, configuring, and securing a management
application that sends commands to and receives replies from a Pathway subsystem:
•
The PATHMON process does not support multiple outstanding requests from the
same program. Only one NOWAIT I/O operation is permitted for each opener.
•
Pathway subsystems do not support cancellation of outstanding commands (that
is, an asynchronous command abort).
If an application calls the CANCEL or CANCELREQ procedure to cancel requests
to the PATHMON process, only the reply is cancelled if the PATHMON process
has already read the command message (that is, the cancellation is partial). The
PATHMON process executes the command and issues a reply, which the
operating system then discards. Cancellation of the command does take effect if
the PATHMON process has not yet read the command message. However, the
application cannot determine whether the command message has been read. If a
new request is sent to the PATHMON process before it has completed processing
a previous cancel request, error 28 is returned.
Figure 2-1. Sending Commands and Receiving Responses
Management
Application
START
PATHWAY
DEF PATHWAY
PATHMON
RESPONSE
PATHMON
Config
File
SSINIT
SSPUT
WRITEREAD
SSGET
Message Buffer
VST006.vsd