SNMP Subagent Programmer's Guide

Fault-Tolerant Hello World Program
2-26 119728—SNMP Subagent Programmer’s Guide
Programming Tutorials
Fault-Tolerant Hello World Program
The NonStop agent provides fault tolerance on a particular host, because it runs as a
NonStop process pair. If the primary agent process fails, a backup agent process having
the same name takes over. In addition, you can configure the NonStop agent to receive
requests simultaneously from multiple controllers. Refer to the SNMP Configuration
and Management Manual for complete information on NonStop agent behavior and
configuration options.
In scenarios such as the following, however, the NonStop agent’s node or
telecommunications lines between the node and manager stations may become
unavailable, making any subagent using that NonStop agent unavailable.
The Fault-Tolerant Hello World subagent demonstrates a technique for providing
subagent tolerance to host and network faults. This subagent accepts a list of NonStop
agent process names at invocation. For each agent with which successful connections
can be established, the subagent simultaneously performs the same functions as
Nowaited Hello World.
These files are related to Fault-Tolerant Hello World:
Functions
Invoke Fault-Tolerant Hello World by specifying the executable subagent name and one
or more NonStop agent process names:
RUN HELLOFT /NAME $FTOL/ \NODE1.$ZSNMP \NODE3.$ZSNMP
helloftc C source code
hellosmi MIB definition
helloftm TACL routine
222
Manager Station
Local Area Network 1
NonStop Agent
Node 1
Subagent
Node 2
NonStop Agent
Node 3
Local Area Network 2