We are currently reviewing SLA calculation by calculating raw data from PRTG. Let us say that we want to calculate SLA from 1 to 31 January 2019 (31 days), in this interval we know this data (by analysing raw data):

  • Uptime: 25 days
  • Downtime: 3 days
  • Unknown: 3 days

My questions are:

  1. How to calculate SLA from that data? Is this correct: SLA = Uptime/(Uptime + Downtime)? So, the 'unknown' will not be used for calculation, right?
  2. What are the main cause of 'unknown' state?
  3. If 'unknown' state occurs in uptime state, can we assume than 'unknown' as uptime? Vice versa, if 'unknown' state occurs in downtime state, can we assume than 'unknown' as downtime?
  4. Is there a way to calculate/count/sum unknown time from raw data fast? By an API maybe.

Thanks a lot in advance.

Article Comments

Benidiktus,

Hello, and thanks for posting your question to our KB.

The best solution for what you're trying to accomplish is handled through our Uptime Alliance partner CORP-IT.

Check out their solution.

PRTG SLA

Note: The SLA Plugin from Corp IT has been deprecated. If you would like to explore enhanced SLA reporting options, check out the PRTG SLA Reporter, a PRTG extension. A free trial is available from the Paessler website.

Thanks!

Benjamin Day
Paessler Support


Dec, 2019 - Permalink

Thanks a lot for the reply, Benjamin. We are doing IT Audit in an institution, so we need the answer from my questions one by one, not a solution using other software. Could you please help us to answer my questions one by one? We appreciate if you can explain us clearly with some additional data/explanation like the algorithm that used by PRTG, may be. Thanks again.


Dec, 2019 - Permalink

How to calculate SLA from that data? Is this correct: SLA = Uptime/(Uptime + Downtime)? So, the 'unknown' will not be used for calculation, right?

  • Correct, Unknown isn't factored into this.

What are the main cause of 'unknown' state?

  • We use an Unknown state to clarify that we do not have enough information from the device to determine 100% that the metric is available or not available.

If 'unknown' state occurs in uptime state, can we assume than 'unknown' as uptime? Vice versa, if 'unknown' state occurs in downtime state, can we assume than 'unknown' as downtime?

  • Yes, unknown is not taken into account when figuring uptime and downtime.

Is there a way to calculate/count/sum unknown time from raw data fast? By an API maybe.

  • Not to my knowledge

Dec, 2019 - Permalink

Thanks a lot for the reply, Benjamin. I really appreciate it.

One more question, how to identifiy unknown state from raw data? Is my bellow algorithm correct?

"Calculate interval of date time from 2 row, if the result above 10 minutes (normal interval is 5 minutes) marks it as unknown"


Dec, 2019 - Permalink

Benidiktus,

No, Unknown should show up as all 0, and coverage will show as 0.

If you want to open a support ticket, and send a screenshot, I can better explain what you're seeing.

Thanks!

Benjamin Day
Paessler Support


Dec, 2019 - Permalink