I'm seeing the same result. This is making it very difficult to provide accurate numbers to upper management.
Hi pflanz, good morning.
Actually I'm checking the same thing and I find this, maybe it could help you understand how the availability works.
Maybe it have some changes with the version of NPM, but I think this is the basic.
This article provides information on how the Availability table works.
By default, we poll every 120 seconds for availability.
This is done with ICMP (Ping).
If the node responds
- It is marked as 100% available and the response time is stored.
If the node does not respond, a fast ping is sent.
- This repeats according to the Response Time Retry Count value for your polling engine.
- This setting designates the number of times Orion retries ICMP pings on a monitored device before packet loss is reported.
- If the node responds to the fast ping, it is marked as 100% available and 100% packet loss to represent that it responded, but not to the main ICMP poll. The response time is not stored.
If the node does not respond to any of the above:
- It will be marked as 100% loss and 0% available for that poll.
As such it is possible to have 100% packet loss and 100% availability.
As ICMP is a low priority packet, the node may be too busy to respond to the poll but the node appears to be operating fine.