| 1 | # Percentile |
| 2 | |
| 3 | The percentile is the average value of a series using only the smaller N percentile of the values. |
| 4 | (a population or a probability distribution). |
| 5 | |
| 6 | Netdata applies linear interpolation on the last point, if the percentile requested does not give a round number of |
| 7 | points. |
| 8 | |
| 9 | The following percentile aliases are defined: |
| 10 | |
| 11 | - `percentile25` |
| 12 | - `percentile50` |
| 13 | - `percentile75` |
| 14 | - `percentile80` |
| 15 | - `percentile90` |
| 16 | - `percentile95` |
| 17 | - `percentile97` |
| 18 | - `percentile98` |
| 19 | - `percentile99` |
| 20 | |
| 21 | The default `percentile` is an alias for `percentile95`. |
| 22 | Any percentile may be requested using the `group_options` query parameter. |
| 23 | |
| 24 | ## how to use |
| 25 | |
| 26 | Use it in alerts like this: |
| 27 | |
| 28 | ``` |
| 29 | alarm: my_alert |
| 30 | on: my_chart |
| 31 | lookup: percentile95 -1m unaligned of my_dimension |
| 32 | warn: $this > 1000 |
| 33 | ``` |
| 34 | |
| 35 | `percentile` does not change the units. For example, if the chart units is `requests/sec`, the result |
| 36 | will be again expressed in the same units. |
| 37 | |
| 38 | It can also be used in APIs and badges as `&group=percentile` in the URL and the additional parameter `group_options` |
| 39 | may be used to request any percentile (e.g. `&group=percentile&group_options=96`). |
| 40 | |
| 41 | ## Examples |
| 42 | |
| 43 | Examining last 1 minute `successful` web server responses: |
| 44 | |
| 45 | -  |
| 46 | -  |
| 47 | -  |
| 48 | -  |
| 49 | |
| 50 | ## References |
| 51 | |
| 52 | - <https://en.wikipedia.org/wiki/Percentile>. |