Ability to convert a count to a rate - getting a simple RPS

[agirbal]

Describe the feature:

Kibana's basic visualizations, or Lens, should have a way to convert your data count to a rate per unit of time, e.g. (request per second). This is the usual way of thinking of metrics ("each of my instances can do 500 RPS") and it should be made easily available.

Describe a specific use case for the feature:

As mentioned to @AlonaNadler, many metrics we look at and compare with other systems is typically expressed as a rate, e.g. "requests per second" or "clients per hour". Usually data in ES is of discrete form, you get 1 document per event (e.g. logs). How do you plot your "logs per second"?

There are some answers out there in Discuss but most of them are wrong:

• use Derivative agg: this only works if your data is a counter that tallies up a value over time, which is not often the case.
• use moving avg or bucket agg: the parameter is a fixed number of entries or time unit to average over. It just does smoothing, so you need to have a rate in the first place, it does not convert your count to a rate.
• adjust kibana's time window: yea, you can get lucky and pick a window so that kibana decides to precisely split your count by that unit of time. Not workable :)
• change the time interval in TSVB: this seems to work but is actually unusable because it makes data granularity extremely small. Looking at more than 30min will actually return an error.
• the only way I found was to use scale_interval in Timelion.
  Thanks!

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[wylieconlon]

We are tracking a request to add Rate already, it would be helpful to only keep one of these issues open. Your comment is adding detail in a way that we aren't tracking yet, could you add it to the other issue? #46627

[agirbal]

Closing as dup of #46627
But I think it'd be very beneficial to also have that feature available in the basic visualization interface, assuming it may take some time for Lens to mature @wylieconlon @AlonaNadler ? Thx!