pjfanning / micrometer-akka   0.13.3

Apache License 2.0 GitHub

A library for monitoring Akka that uses Micrometer metrics

Scala versions: 3.x 2.13 2.12

Build Status Maven Central


⚠️ This project is being ramped down due to Akka's move away from Open Source. It is not expected that the previous iterations of this library (listed below) will continue to be maintained either.

Development has switched to micrometer-pekko instead.

This project is a fork of an early version of Kamon-Akka. The Kamon team have done a great job and if you are just experimenting with metrics collection, then their tools and documentation are a great starting point. This fork produces metrics in Micrometer format.

These are 2 previous iterations of this library:

Differences from Kamon-Akka:

  • we do not support Kamon TraceContexts, as we currently have no use case for them
  • we only support Akka 2.6
  • records time in seconds as opposed to nanoseconds (the data is still a double)
"com.github.pjfanning" %% "micrometer-akka" % "0.13.3"

There is a sample project at https://github.com/pjfanning/micrometer-akka-sample


To enable monitoring, include the appropriate jar as a dependency and include the following Java runtime flag in your Java startup command (aspectjweaver is a transitive dependency of micrometer-akka):


You will also need to set up the Micrometer Meter Registry.

com.github.pjfanning.micrometer.akka.AkkaMetricRegistry#setRegistry (example)


The metrics are configured using application.conf files. There is a default reference.conf that enables only some metrics.



  • differs a little between ForkJoin dispatchers and ThreadPool dispatchers
  • ForkJoin: parallelism, activeThreadCount, runningThreadCount, queuedSubmissionCount, queuedTaskCountGauge stealCount
  • ThreadPool: activeThreadCount, corePoolSize, currentPoolSize, largestPoolSize, maxPoolSize, completedTaskCount, totalTaskCount

Actor System

  • Actor Count
  • Unhandled Message Count
  • Dead Letter Count


  • One metric per actor instance
  • mailboxSize (current size), processingTime, timeInMailbox, message count, error count

Actor Router

  • One metric per router instance, summed across all routee actors
  • routingTime, timeInMailbox, message count, error count

Actor Group

  • Each actor group has its own include/exclude rules and you can define many groups with individual actors being allowed to be included in many groups - the metrics are summed across all actors in the group
  • actorCount (current active actors), mailboxSize (current size), processingTime, timeInMailbox, message count, error count


Copyright © 2017,2018 Workday, Inc.
Copyright © 2013-2017 the kamon project <http://kamon.io/>

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
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