TS/MP Pathsend and Server Programming Manual (H06.05+, J06.03+)

The Pathsend procedures and the LINKMON process or the ACS subsystem processes, however,
do not provide multithreading, fault tolerance, device configuration, or operations management
for requesters. Therefore, if you need these capabilities in a Pathsend requester, you must provide
the programming for them.
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 or the ACS subsystem processes 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” (page 51), 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 or the ACS subsystem processes perform security authorization checks on each send
operation.
The Pathsend procedures and the LINKMON process or the ACS subsystem processes 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 1 (page 39) 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 1 (page 39) 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” (page 129).
38 Designing Your Application