Cisco Active Network Abstraction Administrator’s Guide, 3.5
Page 120 Cisco Systems, Inc.
In addition, the maximum and minimum tolerance levels can be customized
through the system registry. When a VNE is using normal polling and CPU
usage is high, Sheer DNA waits for the maximum CPU usage threshold value
(upper tolerance level) to be exceeded five times (default) and only then does
the VNE move to slow polling, as shown in the diagram below.
Normal polling Slow polling Maintenance
5 times above the
maximum threshold level
5 times below the
minimum threshold level
10 times above the
maximum threshold level
If the VNE is using slow polling after it has been checked five times, then the
VNE is checked a further 10 times (default) to see whether the CPU usage is
still high. If this is the case, the VNE is moved to maintenance mode. Once
the VNE is in maintenance mode the user must manually set the VNE back to
normal polling, (it does not automatically return to regular polling). Once the
VNE is in maintenance mode the device is not polled and no alarms are
reported.
In the example below CPU usage is polled 5 times and it is above the
maximum value, so the VNE moves to slow polling. The CPU usage is the
polled a further 10 times and it is above the maximum value, so the VNE
moves to maintenance mode.
Maximum
threshold
value
Minimum
threshold
value
Normal polling
1. CPU usage is polled 5 times
(and above the max. value)
3. CPU usage is polled
a further 10 times
(and above the max. value)
2. VNE moves to slow polling 4. VNE moves to maintenance