Dear users, Kamon 0.5.1 is out! This is a minor update containing just a few changes, probably the most important being that we reverted a dependency upgrade that made us Java 8 only. Now we are back on Java 6+ land.

When we released 0.5.0 some dependencies were upgraded and made Kamon only work with Java 8, but that upgrade wasn’t really necessary for us. Some of our users are still trapped using Java 6+ and since we have no particular reason to force the upgrade on our side, we reverted a couple changes and made this release compatible with Java 6+ again. That being said, come on! Please folks, upgrade!

We also have a community contribution in this release: thanks to Ferenc Tóth our kamon-system-metrics module can now report metrics on all JVM memory pools.

Finally, we introduced a auto-start feature that sort of helps Kamon to be more test-friendly, as described on issue #202. The gist of it is that you can add to your JVM startup parameters and if some Kamon API is used before Kamon being started, it will start itself using the default configuration sources. Why? Well, you won’t have to add calls to Kamon.start() everywhere in your tests to avoid getting the not so pleasant Kamon has not been started yet. error. This solution is far from ideal, but we think that we got the right idea for solving this problem: what if all of Kamon APIs could be used without you having to start Kamon? more on that later this week :).

Here is a little excerpt from our changelog for this release:

  • kamon:
    • Revert the need to run on Java 8.
  • kamon-core:
    • Make Kamon test-friendly. (see issue #202).
    • Pull the basics of dispatcher metrics for Akka into a more general ThreadPoolExecutor metrics.
  • kamon-akka-remote:
    • Avoid breaking kryo serialization on remote messages. (see issue #160).
  • kamon-play-24:
    • Use the URI’s authority instead of the full URL when naming WS Client request segments.
  • kamon-system-metrics:
    • Report metrics for all JVM memory pools. (see pull #244).

That’s all for this release, more cool stuff is in the oven!