Learn how to retrieve values.

Get values

Getting values runs get on the driver.

NOTE: You can work with values by using Series method as well which allows you to perform additional actions on a series of data easily.

`values(key: String, from: Time, to: Time, range: Symbol, **options)`

key - string identifier for the metrics
from - timestamp you want to get values from
to - timestamp you want to get values to
range - specific range you want to get values in
options - hash of optional arguments:
- config - optional configuration instance of Trifle::Stats::Configuration. It defaults to global configuration, otherwise uses passed in configuration.
- skip_blanks - optional argument that will instruct driver not to return empty hash in timeline when no value was being tracked.

Using from and to gives you flexibility to exactly specify what data you are interested in.

Use range to specify sensitivity of returned data (aka how many data points you want to get). For example if you're trying to get daily values for current a specific month, use range: :day. This will give you ~30 data points. If you need to increase your sensitivity for chart, you may use range: :hour which will give you ~30 * 24 data points.

The more data you're fetching, the slower the response time. Thats a trade-off you need to decide.

Here is an example how to get today values for specific key.

Trifle::Stats.values(key: 'event::logs', from: Time.now, to: Time.now, range: :day)
=> {:at=>[2021-01-25 00:00:00 +0200], :values=>[{"count"=>3, "duration"=>8, "lines"=>658}]}

And here is another how to get daily values for a last 30 days for specific key.

Trifle::Stats.values(key: 'event::logs', from: Time.now - 60 * 60 * 24 * 30, to: Time.now, range: :day)
=> {:at=>[2021-01-25 00:00:00 +0200, 2021-01-24 00:00:00 +0200, ...], values: [{"count"=>3, "duration"=>8, "lines"=>658}, {"count"=>1, "duration"=>3, "lines"=>311}, ...]}

If you're integrating with Rails, don't forget you can use things like 1.month.ago or Time.zone.now - 30.days.

Skip Blanks

Sometimes you may not have event occurence every hour or every day. Whenever you pull longer period of data, you may end up with timestamps and values where no values has been tracked. Trifle::Stats drivers by default return empty hash in these so you can perform continuous calculations (ie slicing in aggregators, etc). The disadvantage of this is that it may create lots of empty data. For example lets say you track something ~4 times a day and you wanna pull data per minute for last 30 days. By default Trifle::Stats would give you 30 (days) * 24 (hours) * 60 (minutes) ~43k of points. Good luck plotting that. But if you know you have lots of empty values in between, you may decide to skip those and then you would get back 30 (days) * 4 (times a day) ~= 120 points. Theres a big difference.

Trifle::Stats.values(key: 'events::logs', from: Time.now - 60 * 60 * 24 * 30, to: Time.now, range: :day)
=> {
  :at => [
    2021-01-20 00:00:00 +0200,
    2021-01-21 00:00:00 +0200,
    2021-01-22 00:00:00 +0200,
    2021-01-23 00:00:00 +0200,
    2021-01-24 00:00:00 +0200,
    2021-01-25 00:00:00 +0200,
    2021-01-26 00:00:00 +0200,
    2021-01-27 00:00:00 +0200,
    ...
  ],
  values: [
    {"count"=>3, "duration"=>8, "lines"=>658},
    {},
    {"count"=>1, "duration"=>3, "lines"=>311},
    {},
    {},
    {"count"=>2, "duration"=>4, "lines"=>541},
    {},
    {},
    ...
  ]
}

And heres how that looks with skip_blanks: true enabled.

Trifle::Stats.values(key: 'events::logs', from: Time.now - 60 * 60 * 24 * 30, to: Time.now, range: :day, skip_blanks: true)
=> {
  :at => [
    2021-01-20 00:00:00 +0200,
    2021-01-22 00:00:00 +0200,
    2021-01-25 00:00:00 +0200,
    ...
  ],
  values: [
    {"count"=>3, "duration"=>8, "lines"=>658},
    {"count"=>1, "duration"=>3, "lines"=>311},
    {"count"=>2, "duration"=>4, "lines"=>541},
    ...
  ]
}