How is the metric Reboots % calculated

Document ID : KB000023367
Last Modified Date : 14/02/2018
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Question:  

How is the metric Reboots % calculated

 
Answer: 
 

If you look at the Element Variable report, you will see that "reboots" is a function of the following formula: reboots/(goodPolls+missedPolls+badPolls+reboots).
So, it could be not 100% because the data is stored along with the good polls. Also note that all data isn't store until we have two contiguous good polls.
This includes the data about poll counters (reboots, missed polls, bad polls...). 

 

In the following polling scenario: 

9:15 Good poll - data saved to database
9:20 Missed poll
9:25 Missed poll
9:30 Good poll - sysuptime shows reboot occurred at 9:17
9:35 Good poll
 

The data isn't stored until 9:35. At that point it shows the following:

Total time monitored = 20 minutes - 9:15 - 9:35
Available time = 18 minutes - 9:17 - 9:35
Reachable time = 10 minutes - 9:25 - 9:35
Delta time = 5 minutes - 9:30 - 9:35


The following values are stored in the database:

Good polls = 2 (9:30 & 9:35 poll)
Missed polls 2 (9:20 & 9:25 poll)
Reboots 1

The formulas would then show;

Good Polls % = 40%
Missed Polls % = 40%
Reboots % = 20%

 
It gets more complex when devices are tracked because the good polls/missed poll count includes interfaces as well.

Additionally, the Max Reboot metric comes from the highest value seen. In the above example, that would be 20%.

 
Additional Information: 

TEC520024 - How to run an Element Variable report