Forum Discussion

Anton639_262757's avatar
Anton639_262757
Icon for Nimbostratus rankNimbostratus
Jul 27, 2016

False alerts being generated

Once or twice a day My F5 Big IP device would generate email alerts saying that either a that either a monitor was triggered or some network device (server/ firewall) state has been changed from green to red when we know for a fact that the devices are fine and functional. Within less than a minute we would be notified that the issue has been resolved. The system we are monitoring is critical and it would cause a lot of problems if we continue getting these false alerts. I understand that the cause would be that the F5 in not receiving some response within a timeout period and that generates the alerts. Is there a way to fix this? Can I eliminate or at least try to minimize as much these false alerts being generated by F5?

 

alerts
application delivery
BIG-IP
devops
false
false positive
LTM
state change
timeout

1 Reply

Sort By
  • Vijay_E's avatar
    Vijay_E
    Icon for Cirrus rankCirrus
    Jul 27, 2016

    Such alerts usually show up when the pool member fails to respond to health monitors. You can confirm this by checking the logs. There are times when the pool member may not respond to a health check because it is busy processing other traffic. In that case, changing the default timeout and interval on the health-check monitors would help.

     

    You can increase the timeout & interval within the monitor if you want to reduce such alerts. Timeout is usually 16s and Interval is 5s. You can change it to 10s Interval and 31s Timeout. Timeout needs to be [(3*Interval) + 1] as a recommended best practice.