OSI/MHS Configuration and Management Manual

Sizing and Tuning Your OSI/MHS Subsystem
OSI/MHS Configuration and Management Manual—424827-003
8-7
Configuring Supporting Software
the same MTA; in this case, by listing the links in a different order in each MTA object
definition, you can use multiple links to an adjacent MTA simultaneously.
Startup Files
It is common to use command files to start up an OSI/MHS subsystem, but using one
large command file to start all the objects can compromise performance. Two factors
most affect startup performance:
•
Overhead for starting many processes simultaneously
•
Contention for the OSI/MHS configuration files
Splitting the startup command file into several smaller files and running them
separately often results in faster startup. Running the files in parallel might result in
slower startup than running them in sequence because of contention problems.
Another practice recommended for system startup is to define a process that various
OSI/MHS processes can use as their home terminal. In general, a large number of
system processes—not just the processes of OSI/MHS—attempt to open the home
terminal immediately upon startup. If that terminal is, in fact, a physical device, the
maximum number of openers allowed by the operating system can be exceeded. By
assigning a process as a virtual home terminal, you can avoid this problem.
Configuring Supporting Software
Satisfactory performance of OSI/MHS depends on an appropriate configuration of
several other products.
OSI/AS, OSI/TS, and X25AM
Just as parallel processing can improve the performance of OSI/MHS, it can increase
the efficiency of underlying subsystems. You can use multiple instances of OSI/AS
and OSI/TS to distribute the communications workload over multiple connections and
addresses. (Multiple TSP processes can run over the same X.25 connection but not
over the same LAN.)
Note. SCF reports an error if you give any two links exactly the same set of addresses. To
avoid this error in a configuration in which multiple MTA objects point to the same MTA, assign
a different PSEL to each of the matching links.
Note. Do not use a dynamic device as the home terminal. Use a permanently configured
logical device or a process whose name will not vary from one execution to the next. Some
options for virtual home terminal are a static Telnet window, an asynchronous terminal
configured as a logical device, or an HP NonStop
™ Virtual Hometerm Subsystem (VHS).
If the home terminal (or virtual home terminal) becomes unavailable, problems arise during
restart or recovery of a group. OSI/MHS reports event message 3 with PROCESS_CREATE_
error 8, 14. To remedy the problem, restart the home terminal device or process and use the
same name previously assigned to it.