Flapping occurs when a service or host changes state too frequently, this causes lot of problem and recovery notifications.
Once you have defined Flapping explain how Nagios detects Flapping.
- Whenever Nagios checks the status of a host or service, it will check to see if it has started or stopped flapping. Nagios follow the below procedure to do that:
- Storing the results of the last 21 checks of the host or service analyzing the historical check results and determine where state changes/transitions occur.
- Using the state transitions to determine a percent state change value (a measure of change) for the host or service.
- Comparing the percent state change value against low and high flapping thresholds
- A host or service is determined to have started flapping when its percent state change first exceeds a high flapping threshold.
- A host or service is determined to have stopped flapping when its percent state goes below a low flapping threshold.