InfluxDB Docs

monitor.check() function

The monitor.check() function function checks input data and assigns a level (ok, info, warn, or crit) to each row based on predicate functions.

Function type: Transformation

import "influxdata/influxdb/monitor"

monitor.check(
  crit: (r) => r._value > 90.0,
  warn: (r) => r._value > 80.0,
  info: (r) => r._value > 60.0,
  ok:   (r) => r._value <= 20.0,
  messageFn: (r) => "The current level is ${r._level}",
  data: {}
)

monitor.check() stores statuses in the _level column and writes results to the statuses measurement in the _monitoring bucket.

Parameters

crit

Predicate function that determines crit status. Default is (r) => false.

Data type: Function

warn

Predicate function that determines warn status. Default is (r) => false.

Data type: Function

info

Predicate function that determines info status. Default is (r) => false.

Data type: Function

ok

Predicate function that determines ok status. Default is (r) => true.

Data type: Function

messageFn

A function that constructs a message to append to each row. The message is stored in the _message column.

Data type: Function

data

Data to append to the output. InfluxDB populates check data.

Data type: Object

Examples

Monitor disk usage

import "influxdata/influxdb/monitor"

from(bucket: "telegraf")
  |> range(start: -1h)
  |> filter(fn: (r) =>
      r._measurement == "disk" and
      r._field = "used_percent"
  )
  |> monitor.check(
    crit: (r) => r._value > 90.0,
    warn: (r) => r._value > 80.0,
    info: (r) => r._value > 70.0,
    ok:   (r) => r._value <= 60.0,
    messageFn: (r) =>
      if r._level == "crit" then "Critical alert!! Disk usage is at ${r._value}%!"
      else if r._level == "warn" then "Warning! Disk usage is at ${r._value}%."
      else if r._level == "info" then "Disk usage is at ${r._value}%."
      else "Things are looking good."
  )