SNAX/HLS Configuration and Control Manual

Step 4. Planning the Application Environment
Planning the SNAX/HLS Environment
104705 Tandem Computers Incorporated 2–15
PS Usage
The PS usage field is not interpreted by SNAX/HLS. In the BIND message, the PS
usage field is indicated in bytes 15-25. In HLSRDT, this attribute is specified by the
BIND attribute, PS-USAGE.
Primary LU Network Name This field is critical when the SNAX/HLS application is the primary session partner.
Many controller installation and customization processes cause the controller to accept
a BIND from only an appropriately named PLU. You can define the name of the PLU
in the BIND record of the RDT (resource definition table) to communicate successfully
with a session partner running in such a situation. Alternately, the PLU name can be
supplied by the application when the session is established.
If the SNAX/HLS application is a secondary session partner, the network name of the
PLU is returned in the APPLICATION-NAME field of the OPEN-SESSION and
HLS-OPEN reply. This name can be interrogated by the SNAX/HLS application for
security and other purposes.
In the BIND message, the primary LU network name is indicated after the
cryptography field. In HLSRDT, this attribute is specified by the BIND attribute,
PLU-NAME.
User Data This field provides arbitrary text. Its use is application-dependent. In SNAX/HLS
application, this field can be specified when the BIND is defined (in HLSRDT), or can
be overridden by run-time data in the HLS-OPEN verb.
In the BIND message, the user data field follows the primary LU network name field.
In HLSRDT, this attribute is specified by the BIND attribute, USER-DATA.
Step 4. Planning the
Application
Environment
This subsection discusses the planning of the application environment. The goal is to
promote efficient use of resources and to define the environment and applications
such that changes in the environment do not require major coding changes in the
application programs. The discussion covers (1) the key issue of handling session-
establishment parameters (such as the run-time binding of the SNAX/HLS process
name and LU names) using the HLS-ALLOCATE and HLS-OPEN verbs, and (2) the
planning of the Pathway environment for the case where the SNAX/HLS process is
defined as a server to the Pathway system.
Run-Time LU and PROFILE
Naming
If an application can derive most of the information required for session establishment
at run time, it can adapt to changes in the environment. This adaptability allows you
to change network configuration and session profiles without recompiling the
application programs. To attain adaptability in your application, you may for
example, specify the SNAX/HLS process PROFILE and LU names at run time as
follows:
Specify the PROFILE name as the file-name part of the IN file.
Specify the SNAX/HLS process and LU names as the OUT file-name of the
standard startup message.