Akka 2.6.0-M7 released

Dear hakkers,

The seventh development milestone for Akka 2.6 is out.

It would be excellent if you can try the milestones out and give us feedback. Akka 2.6 is binary backwards compatible with 2.5 with the ordinary exceptions listed in the documentation. Some configuration changes may be needed, please read the migration guide as a first step.

Some notable changes in 2.6.0-M7:

  • Simplify running of Akka Streams with an ActorSystem without creating a Materializer, #25559
  • Deprecate ActorMaterializer in favor of just Materializer or ActorSystem, #25559
  • Propagate stream cancellation causes #27472
  • Don’t run Scheduled task when ActorSystem is shutting down, #16495
  • Fix race when binding to port 0 in Artery TCP, #27525
  • Fix issue that may cause multiple active Cluster Singleton actors when several nodes leave at the same time (backported to 2.5.25), #27527
  • Changed variable substitution in config library, #27249
  • Deprecate persistent mode of Cluster Sharding in favor of ddata mode, #27528
  • Deprecate Cluster Client in favor of Akka gRPC, see migration guide,
  • SLF4J logging API in Typed #26537
  • Utility for testing logging events, LoggingEventFilter in Typed TestKit #24348
  • Change “Untyped” to “Classic” in documentation and adapter methods, #27627
  • New guide for learning Akka Typed from Classic, #25624
  • Many improvements to the Akka Typed reference documentation, and this effort will continue.

A total of 44 issues were closed since 2.6.0-M6. The complete list can be found on the 2.6.0-M7 milestone on github.


For this release we had the help of 11 committers – thank you all very much!

commits  added  removed
     34  10722     7856 Patrik Nordwall
     16   4684     4956 Johan Andrén
     10   1067     1024 Arnout Engelen
      7   1190     1291 Helena Edelson
      2     34       16 Johannes Rudolph
      1   1178     1648 franciscolopezsancho
      1     34      679 Christopher Batey
      1      8       31 Tim Moore
      1     11       11 heraklos
      1     11        1 Renato Cavalcanti
      1      5        2 Enno

Thanks to Lightbend for their continued sponsorship of the Akka core team’s efforts. Lightbend offers commercial support for Akka.

Happy hakking!

– The Akka Team

Is there a matching release for the akka-management, alpakka, alpakka-* and split brain resolver released as well ?

All those should work with 2.6.0-M7 if you override the dependencies, because it is binary backwards compatible with 2.5.x.

If you find any problem using those with 2.6.0-M7 we would like to know.

There might be a problem with one of the Alpakka modules, Alpakka mqtt, but I’m not sure.

Alpakka’s mqtt-streaming is now 2.6 compatible given that it now avoids 2.5’s StashBuffer.

On the subject of binary compatibility though, was the change to StashBuffer the only break 2.6 makes?

The Typed modules are marked ApiMayChange and not binary backwards compatible yet. They will be from 2.6.0.

The list of changes from 2.5.25 is in the migration guide.


It breaks for me. Shall I file issues on github, or mention them here ?


Please create an issue in akka/akka and we will look into it tomorrow.