On 13 Apr 11:56, Shubham Choudhary wrote:
> I am using the Prometheus recording rule to capture the CPU usage over 5
> mins and later want to use it to get maximum CPU used for 5 mins in the
> last 30 days.
>
> Recording Rule
>
> - expr: 1 - avg by (instance)
> > (rate(node_cpu_seconds_total{mode="idle"}[5m]))
> > record: instance:node_cpu_usage:rate5m
>
>
> Max. CPU used in last 30 days over 5 mins
>
> max_over_time(instance:node_cpu_usage:rate5m[30d])
>
>
> Now, let's imagine a situation where Prometheus starts to pull data with an
> interval of 15sec which started at 00:00:00 so
>
> 1. 1st pull was at 00:00:00. Here, the instance:node_cpu_usage:rate5m is
> not calculated since the rate function needs a minimum of 2 data points.
> 2. 2nd pull was at 00:00:15. *Here, the instance:node_cpu_usage:rate5m
> is calculated as the difference of 2nd pull - 1st pull data divided by 300
> seconds. Now, this is the issue of why rate function dividing by 300
> instead of 15.*
> 3. 3rd pull was at 00:00:45. Again, the same scenario occurs.
> 4. The wrong data is being saved in instance:node_cpu_usage:rate5m till
> 5th minute.
Please provide the raw data:
node_cpu_seconds_total{mode="idle"}[1h] in the "table" view.
Thanks.
>
> [image: prometheus_rate_less_data.png]
>
>
> *So, doing a max_over_time(instance:node_cpu_usage:rate5m[30d]) will for
> sure give me the first value which is wrong.*
> Also if there are server crashes or network issue then the rate gives wrong
> data.
>
> How can I overcome this outlier?
>
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--
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//\ Open-Source Consultant
V_/_ Inuits - https://www.inuits.eu
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