RSC/MP 7.2 Programming Manual

RSC/MP Sessions
HP NonStop Remote Server Call (RSC/MP) Programming Manual—522360-004
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The IDS Session Type
Select the Pathsend delivery mechanism by calling RscWrite or RscWriteRead with a
Servername whose first character is NOT a dollar sign ($) or backslash (\).
TMF Transactions
Each RSC/MP Interprocess session provides the context to support a TMF transaction.
Applications can use this feature when the effects of several server I/O operations
must be committed all together or not at all. When engaged, the transaction
encompasses all RscWrite and RscWriteRead calls within the session; a session does
not support multiple concurrent transactions. The RSC/MP application controls the
transaction explicitly by using RscBeginTransaction, RscEndTransaction, and
RscAbortTransaction, or implicitly by using various option settings (see Generating
Transactions Automatically (Implicitly) on page 6-8).
The IDS Session Type
The Intelligent Device Support (IDS) session type is used to communicate with
Pathway servers through the Pathway/TS TCP.
An IDS session provides the following features:
•
Communicates and manages routing of messages to Pathway servers.
•
Sends up to 8192 bytes per message.
•
Allows one outstanding nowaited I/O.
•
Uses a SCREEN COBOL requester to define TMF transaction boundaries.
•
Can be automatically started and stopped by the TDP (RSC/MP uses the
Subsystem Programmatic Interface to Pathway/TS).
The IDS session type requires an IDS requester written in SCREEN COBOL. The IDS
requester forwards messages from the RSC/MP Host to Pathway servers through
SCREEN COBOL TCPs. An IDS requester is provided as part of the RSC/MP product
on NonStop; a customized requester can be substituted.
For IDS sessions, set the TCLPROG_NAME and INITIAL_NAME options before using
the RscBeginSession function call. The TCP_NAME option can also be set to define
the name of the TCP that the IDS session is to use. See Appendix D, API Option
Definitions, for more information about these options.
An application uses the RscWriteRead function call to send messages, in the format
defined by the application, to an application-specific IDS requester on the Nonstop
system. The RscWrite function is not supported for IDS sessions.
The workstation application does not specify the name of the Pathway server it is to
communicate with; instead the IDS requester determines the server. The IDS requester
does not communicate the server class names to the client application.
For IDS sessions, the workstation application cannot use the RSC/MP API functions
RscBeginTransaction, RscEndTransaction, or RscAbortTransaction. Instead, the IDS