SNMP Configuration and Management Manual

TCP/IP Subagent
SNMP Configuration and Management Manual—424777-006
8-9
Refreshing MIB Values
Refreshing MIB Values
The TCP/IP Subagent does not access TCP/IP data on demand. At startup time and at
regular intervals, data is refreshed, stored in a cache, and returned to the manager
through the SNMP agent when MIB values are requested.
Cache Refresh Timers
The TCP/IP Subagent supports three configurable timers for refreshing cached MIB
values:
•
The information cache refresh timer
•
The status cache refresh timer
•
The statistics cache refresh timer
You set these refresh timer values with the -info, -status, and -stats startup parameters
respectively when you start the subagent, as described in Starting the TCP/IP
Subagent on page 8-12.
After the subagent is running, you can refresh values on demand by setting the TCP/IP
Subagent private ztsaInfoCache, ztsaStatusCache, and ztsaStatsCache objects from
an SNMP manager. These objects are described in detail in Table 8-3, Private (ZTSA)
MIB Objects Supported by the TCP/IP Subagent, on page 8-21.
The Information Cache Refresh Timer
The information cache or “info cache” timer controls the rate at which the TCP/IP
Subagent updates values of objects that it retrieves by issuing a SPI INFO command.
This information is relatively static. The info cache timer is initially set with the -info
startup parameter and can be managed through SNMP by setting the ztsaInfoCache
object.
You can disable the info cache timer by setting the ztsaInfoCache object to 0. A value
of 0 indicates that the info cache is refreshed only when the ztsaRefreshNow object is
set to 1 (forceDynamicRefresh).
The Status Cache Refresh Timer
The status cache timer controls the rate at which the TCP/IP Subagent updates values
of objects that it retrieves by issuing a SPI STATUS command. The status cache timer
is initially set with the -status startup parameter and can be managed through SNMP
by setting the ztsaStatusCache object.
You can disable the status cache timer by setting the ztsaStatusCache object to 0. A
value of 0 indicates that the cache is refreshed only when the ztsaRefreshNow object
is set to 1 (forceDynamicRefresh).
Note. HP does not recommend disabling cache timers (by setting their values to 0). If one
timer is set to 0, set all timers to 0 for consistency.