Settings Overview

You're blind without metrics. Metrics should also be easy to add to you application and have little performance impact. This module allows you to define metrics with ease and see inside your application.

Instruments has the following types of metrics that closely mirror statsd.

• Counters: Allow you to increment or decrement a value.
• Gauges: Allow you to report a single value that changes over time
• Histograms: Values are grouped into percentiles
• Timings: Report a timed value in milliseconds
• Measurements: Measure the execution time of a function
• Sets: Add a value to a statsd set
• Events: Report an event like a deploy using arbitrary keys and values

basic-usage

Basic Usage

Reporting a metric is extremely simple; just use the Instruments module and call the appropriate function:

defmodule ModuleThatNeedsMetrics do
   use Instruments

  def other_function() do
    Process.sleep(150)
  end

  def metrics_function() do
    Instruments.increment("my.counter", 3)
	Instruments.measure("metrics_function.other_fn_call", &other_function/0)
  end
end

custom-namespaces

Custom Namespaces

Often, all metrics inside a module have namespaced metrics. This is easy to accomplish using CustomFunctions

defmodule RpcHandler do
  use Instruments.CustomFunctions, prefix: "my_service.rpc"

  def handle(:get, "/foo/bar") do
    increment("foo.bar")
  end
end

The above example will increment the my_service.rpc.foo.bar metric by one.