TS/MP Pathsend and Server Programming Manual (G06.24+, H06.03+)

Designing Your Application
NonStop TS/MP Pathsend and Server Programming Manual–132500
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Pathsend Requesters
In addition, Pathsend procedure calls that send messages to server classes must be
protected by the TMF subsystem to ensure data integrity in your Pathway application.
The Pathsend procedures and the LINKMON process do not support the checkpointing
of Guardian interprocess message synchronization IDs. This lack of checkpointing
support is an important consideration when writing fault-tolerant requester programs
that do not use the TMF subsystem. Section 3, Writing Pathsend Requesters
, provides
more information about writing fault-tolerant Pathsend programs.
The Pathsend procedures allow you to indicate a specific timeout value for each message
sent to a server class. For example, if you perform SERVERCLASS_SEND_ calls to
local and remote systems, you can specify shorter timeout values for the local sends and
longer values for the remote sends.
You can restrict access to Pathway server classes by Pathsend requesters by having the
LINKMON process perform security authorization checks on each send operation.
The Pathsend procedures and the LINKMON process log error messages in the event of
a processing failure. Your Pathsend requester can check for these errors and perform
recovery actions.
Program Structure
The example in Example 2-1 outlines a Pathsend requester program written in TAL.
This program handles data entry for the order-processing application introduced at the
beginning of this section.
Note. The program in Example 2-1 illustrates program structure only; it is not a complete
program. For an example of a complete, running Pathsend requester program, refer to
Appendix B, Examples.