HP T9576G06, Management Manual

Page: 240 / 778

TCP/IP Subagent
SNMP Configuration and Management Manual — 424777-006
8- 10
Initiating Backup Process Takeover
The Statistics Cache Refresh Timer
The statistics cache or “stats cache” timer controls the rate at which the TCP/IP
Subagent updates values of objects that it retrieves by issuing a SPI STATISTICS
command. Statistical data is relatively volatile. The stats cache timer is initially set with
the -stats startup parameter and can be managed through SNMP by setting the
ztsaStatsCache object.
You can disable the stats cache timer by setting the ztsaStatsCache object to 0. A
value of 0 indicates that the cache is refreshed only when the ztsaRefreshNow object
is set to 1 (forceDynamicRefresh).
Dynamic Refresh
Setting the TCP/IP Subagent private ztsaRefreshNow object to 1 forces a refresh of
the MIB-II irrespective of the refresh timer settings. Once the MIB-II values have been
updated, the value of ztsaRefreshNow returns to 0 (autoDynamicRefresh), and the
values in the refresh timer objects (ztsaInfoCache, ztsaStatusCache, and
ztsaStatsCache) once again determine the rate at which MIB-II values are refreshed.
These objects are described in detail in Table 8-3, Private (ZTSA) MIB Objects
Supported by the TCP/IP Subagent, on page 8-21.
Initiating Backup Process Takeover
The TCP/IP Subagent can be run as a process pair to achieve basic fault tolerance.
The support includes a persistent subagent process and checkpointing of the startup
parameters.
To run the TCP/IP Subagent as a process pair and have the backup process take over
in case the primary process fails, include the -b startup parameter when you start the
subagent. For example:
RUN TCPIPSA /NAME $ZTSA, NOWAIT/ -b 6
You can force the backup process to take over and a new backup process to be
created by setting the value of the ztsaSwitchToBackupNow object to 1
(forceBackupTakeover) from an SNMP manager.
Note. You must specify a backup CPU. Otherwise the TCP/IP Subagent does not run as a
process pair.