TCP/IP (Parallel Library) Migration Guide

The New Socket Provider
HP NonStop TCP/IP (Parallel Library) Migration Guide—522272-003
2-3
Compatibility
Compatibility
Consider these compatibility issues when using TCPSAM:
•
Event Management Service (EMS)
•
Fault-Tolerant Behavior
•
SCF on page 2-5
•
Trace on page 2-5
Event Management Service (EMS)
TCPSAM uses the same subsystem ID (ZTCI) as conventional TCP/IP. The EMS
messages issued by TCPSAM are a subset of the ones issued by conventional
TCP/IP.
Fault-Tolerant Behavior
The difference in implementation between conventional TCP/IP and TCPSAM in terms
of where the actual socket is created and what a socket backup open does results in a
slightly different fault-tolerant behavior of TCPSAM compared to TCP/IP process of
conventional TCP/IP.
TCPSAM can be started as a continuously available process pair similar to
conventional TCP/IP. The similarities between conventional TCP/IP and TCPSAM are
listed below.
Similarities
•
When the TCPSAM primary processor fails, the backup takes over as the primary.
When the processor is reloaded, the primary creates a backup on that processor.
•
When the TCPSAM backup processor fails, the TCPSAM primary process restarts
the backup when the processor is reloaded.
Differences
Applications can be fault-tolerant, but sockets are not fault-tolerant in the Parallel
Library TCP/IP environment.
For other differences, see Table 2-1, Fault-Tolerant Behavior; Conventional TCP/IP
Process Compared to TCPSAM, on page 2-4.