Last Modified: Sep 13, 2023
Affected Product(s):
BIG-IP GTM
Known Affected Versions:
12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1
Fixed In:
14.1.0, 14.0.0, 13.1.1.2, 12.1.3.7
Opened: May 07, 2018 Severity: 2-Critical Related Article:
K25348242
When sufficient resources are configured with the same monitor interval, and the monitor timeout value is no more than two times the monitor interval, the monitored resource may be marked as unavailable (due to a timeout) then immediately changed to available.
Monitor probes are not consistently performed at the configured interval.
Monitor interval is lower than the number of resources configured with the same monitor interval.
Set the monitor interval to a value greater than the number of resources monitored using that same interval value. The key to this workaround is to ensure that the sum of the resources monitored at a given interval is not greater than the interval. That can be accomplished several ways depending on your configuration and requirements. For example, if the monitoring interval is 30 seconds and there are 40 different monitors with a 30-second interval and each monitor is assigned to exactly one resource, there are at least two options: -- Change the interval for 10 of the monitors to a different value. -- Set the monitor interval to 40. Note: If you change the monitor interval, make sure to also change the timeout value to follow best practices: timeout value = (3 x interval) + 1.
Monitoring is now consistently performed at the configured interval regardless of the number of resources with the same monitor interval.