PromQL to merge two metrics data

[neel patel]

Hi,

How can we merge two metrics data in a prometheus query so that grafana will plot it in a single graph rather than individual data.

I am using the below query to plot the data in my dashboard.

system_total_processes{instance=~"$host"}

system_running_processes{instance=~"$host"}

I read the PromQL docs but didn't find anything regarding merging 2 metrics So how to merge both above metrics using a single query so that we can get the data with 2 rows. Any pointers will be appreciated?

Thanks in Advance

[Julien Pivotto]

On 22 Jun 14:14, neel patel wrote:
> Hi,

You are looking into adding multiple queries in Grafana. Grafana
supports up to 26 queries per panel.

Look for + Query button:
https://grafana.com/static/img/docs/queries/prometheus-query-editor-7-0.png


regards,


>
> Thanks in Advance
>
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Julien Pivotto
@roidelapluie

[neel patel]

Hi Julien,

Yes, you are right. Thanks for your input. Appreciated.

Thanks,

Neel Patel

[Harkishen Singh]

Either you can go the grafana way, or you can query something smarter like,

{__name__=~"system_.*"}

but that will give you all the queries starting with systems. So, you can add some or/and conditions there as well and make it more productive.

[Harkishen Singh]

Actually, this is the Prometheus way,

{__name__=~"system_total_processes|system_running_processes", instance=~"$host"}

for your use case!

[Brian Candler]

I'd suggest that's not the prometheus way, because it's rare to have two metrics which actually mean exactly the same thing (and if they did, they ought to have the same metric name, and different labels)

Therefore, a single query which mixes multiple metrics into one result set is usually a bad idea.

In this particular instance - total processes and running processes - it might be OK; but even then, if you had (say) 3 systems being shown, which means you get 6 metrics, having them mixed together is usually not useful.