Dear hAkkers,

We—the Akka committers—are pleased to announce the availability of Akka 2.3.3. This is the third maintenance release of the 2.3 branch. It contains fixes for several issues and performance improvements.

Akka 2.3.3 is released for Scala 2.10.4 and 2.11.1. If you were using Akka 2.3.2 for Scala 2.11.0 you need to update immediately, because serialization was broken in Scala 2.11.0. Therefore Akka 2.3.3 for Scala 2.11.1 is not serialization backwards compatible with Akka 2.3.2 for Scala 2.11.0.

This release is backwards binary compatible with version 2.3.0, 2.3.1 and 2.3.2 which means that the new JARs are a drop-in replacement for the old one (but not the other way around) as long as your build does not enable the inliner (Scala-only restriction). Always make sure to use at least the latest version required by any of your project’s dependencies.

Migrating from Older Relases

When migrating an existing project from Akka 2.2.x please have a look at our migration guide.

2.3.3 compared to 2.3.2:

  • 41 tickets closed
  • 185 files changed, 12704 insertions(+), 482 deletions(-)
  • … and a total of 10 committers!

Full list of fixed tickets:

  • 13742 Replace the PhiAccrualDetector with a simple timeout detector
  • 13890 Activator template for Actor for Java 8
  • 13960 Optimize EndpointWriter unstashing
  • 13966 UntypedActorContext.become() defaults to keeping the old behavior
  • 13969 Update to Genjavadoc 0.7
  • 13972 Make DistributedPubSubMediator support consumer group pattern
  • 13985 Log remote disassociate from transport failure detector
  • 13989 Trigger heartbeat for transport failure detector from received payload
  • 13993 Send UnsubscribeAck in DistributedPubSubMediator to the right sender
  • 15025 Stop test actors from logging received messages
  • 15116 Update to Typesafe config 1.2.1
  • 15232 Add putByteArrayUnsafe optimization to ByteStringBuilder
  • 15234 Add new google analytics tracker


commits added removed
  33    6046    1425 Patrik Nordwall
  32    4866    1565 Roland Kuhn
   6     409       9 Björn Antonsson
   6    2051     570 Endre Sándor Varga
   2     213      23 Konrad Malawski
   2      10       1 Martynas Mickevicius
   1     223      42 Xingrun CHEN
   1       8       3 Mathias
   1     652       6 Martin Krasser
   1      15       1 Ahmed Soliman

Additional Release Details

The artifacts comprising this release have been published to and also to Maven Central. In addition, we adopted the sbt standard of encoding the Scala binary version in the artifact name, i.e. the core actor package’s artifactId is “akka-actor_2.10” and “akka-actor_2.11”.


Maven repository:

Binary distribution:


Issue tracker:

Mailing list:

Akka is released under the Apache V2 license.

Happy hAkking!




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