What is a Counter Monitoring Metric? ie Increasing counter)

About

A counter is a metrics type that:

• increments its value by one starting from 0.
• is reset to zero when:
  • the service restarts.
  • a maximum value is reached
• is used to record occurrences of events
• is plotted with a rate function into some specific interval.

This is the same as many counters in the world such as the mileage counter in a car.

Without rate aggregation over a time window, this metric is not really useful and represents only:

• the velocity (the rapidity with which the counter is incremented)
• and the longevity of the service.

Usage / Example

They are used to measure the rate (the throughput) at which some event is occurring over a given time interval.

Example:

• the number of pages loaded
• customer arrivals
• in a queue, counters can measure things like the rate at which items are being inserted and removed.

Report

A counter reports:

• the number of observations,
• its current value
• the minimum and maximum values.

Example

Micrometer

¹⁾

Counter counter = Counter
    .builder("counter")
    .baseUnit("beans") // optional
    .description("a description of what this counter does") // optional
    .tags("region", "test") // optional
    .register(registry);