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

Introduction to Pathway Application Programming
NonStop TS/MP Pathsend and Server Programming Manual–132500
1-6
Other Tandem Fundamentals
Besides process pairs and server classes, fault tolerance in a Pathway application is
ensured by the PATHMON process, the TCP, and the TMF subsystem. Using
information stored in the PATHMON configuration file, the PATHMON process
automatically restarts processes at their initialization level after a failure, allowing these
processes to resume work immediately.
Other Tandem Fundamentals
Besides data integrity and fault tolerance, the Pathway environment also provides the
high performance and low cost, system security, scalability, and distributed processing
of Tandem NonStop systems.
High Performance and Low Cost
The more transactions your system can process (preferably without degrading response
time), the lower the cost of each transaction. The Pathway environment supports fast
response time and high system throughput by allowing:
•
Component processes in a Pathway application (for example, requester and server
processes) to reside and execute concurrently in different processors of a
multi-processor system or even a network. This is called multiprocessing.
•
More than one Pathway application to run in a Tandem NonStop system.
NonStop TS/MP also supports fast response time and high system throughput by
allowing the replication of processes and programs and the distribution of processes. For
example:
•
The PATHMON process can dynamically create additional copies of server
processes at times of peak demand and delete the additional servers when activity
slows again.
•
You can add copies of requester and server programs to your Pathway application to
maintain fast response time when the number of users or terminals increases.
•
You can distribute processes such as requesters and servers close to the resources
they manage, reducing interprocess communication time within a network.
•
You can distribute requesters and servers to less active processors if peak activity on
a particular processor is affecting throughput or response time.
System Security
The Guardian operating environment includes basic mechanisms for controlling access
to files, whether they are data files or program files. Because NonStop TS/MP runs in
the Guardian operating environment, Guardian system security parameters also apply to
Pathway users and processes. In addition, you can supplement the security features of
the Guardian environment with the Safeguard product, which provides authentication,
authorization, and auditing capabilities for Guardian files.