Dear hakkers,

Today we are excited to announce the availability of the Akka 23.05 release. It consists of the following modules:

• Akka (core) 2.8.2
• Akka HTTP 10.5.2
• Akka gRPC 2.3.2
• Akka Management 1.4.0
• Alpakka Kafka 4.0.2
• Alpakka 6.0.1
• Akka Persistence R2DBC 1.1.0
• Akka Persistence JDBC 5.2.1
• Akka Persistence Cassandra 1.1.1
• Akka Projections 1.4.0
• Akka Diagnostics 2.0.0

New features

For deeper insight into some of these new features, please visit the Lightbend blog, which will be featuring a new feature weekly for the next month.

The noteworthy features are:

• Akka Distributed Cluster is a set of features that will help you with stretching an Akka Cluster over geographically distributed locations, and provides asynchronous communication between different Akka Microservices without using a message broker. It comes with new features such as:
  • Projections over gRPC - asynchronous brokerless service-to-service communication.
  • Replicated Event Sourcing over gRPC - active-active entities.
  • Dynamic event filters that can be defined on both the producer and on the consumer side, and they can be changed at runtime.

• Improved rolling updates in Kubernetes by defining Pod deletion cost corresponding to Akka Cluster member age and Akka Cluster app-version from Kubernetes revision.

• Dynamic scaling of number of Sharded Daemon Processes, e.g. Projection instances.

• Storing a query representation of Durable State without using asynchronous Projection processing.

• Store event, snapshot and durable state payloads as JSON in PostgreSQL with Akka Persistence R2DBC.

• Database cleanup tool in Akka Persistence R2DBC.

• mapAsyncPartitioned Streams operator

• Using Akka Cluster with mTLS and rotated certificates in Kubernetes.

• Scala 3 support in:
  • Akka HTTP
  • Akka gRPC
  • Akka Management
  • Akka Persistence R2DBC
  • Akka Persistence Cassandra
  • Akka Projections (some modules)
  • Alpakka Kafka
  • Alpakka (some modules)
  • Akka Diagnostics

• Akka Diagnostics with Thread Starvation Detector and Config Checker.

• Automatic expiry of Distributed Data entries and subscribe to entries with wildcard naming. This is useful for building cache like data structures with Distributed Data.

Security Updates

We run automated security vulnerability and license policy scanning of dependencies. Several dependencies have been updated to fix security vulnerabilities and keep up with latest improvements. Security scans with several other tools have also been performed without detecting any vulnerabilities.

The following CVE’s are addressed in this build.

• CVE-2023-29471
• CVE-2023-31442
• CVE-2023-33251
• CVE-2022-41915
• CVE-2022-3509
• CVE-2022-3510
• CVE-2022-3171

Bug fixes

• Concurrency issues in Event Sourced Behavior retention process, akka #31785
• Integer overflow in Event Sourced Behavior retention, akka #31717
• State consistency issue when deleting Durable State, akka #31752
• Release of Kubernetes lease when used with Cluster Sharding, akka #31715
• Rolling update problem with ClusterShardingHealthCheck, akka #31271
• Missing event in Projection R2DBC, akka-persistence-r2dbc #371
• Sharding with separate Coordinator role, akka #31637
• NullPointerException in Streams shutdown, akka #30201
• Race condition in Streams BroadcastHub initialization, akka #31530
• Streams groupBy incorrectly failing for element on closed substream, #30205
• TLS session is updated too late for TLS 1.3, akka #31419
• Fix Content-Length when HTTP entity is unallowed, akka-http #4214
• HTTP/2 error when parsing percent-encoded query string, akka-http #4226
• HTTP/2 exception from handler, akka-http #4241
• gRPC client with TLS and a custom SslContext, akka-grpc #1728

Other improvements

• Kubernetes Deployment descriptors in the Akka Guide samples
• gRPC mutual authentication with TLS
• Recommendation to use CooperativeStickyAssignor Consumer Assignment Strategy in Alpakka Kafka
• Optimizations of spawning typed actor behaviors, and typed actor memory footprint.
• Sharding entity-recovery-constant-rate-strategy rate per entity type, akka #31836

Dependency updates

• Jackson 2.13.5
• Scala versions have been updated to 2.12.17, 2.13.17 and 3.2.2
• Scala-xml 2.1.0 in builds
• r2dbc-postgresql 1.0.1, including Netty 4.1.89 (CVE-2022-41915)
• protobuf-java 3.21.9 (CVE-2022-3509, CVE-2022-3510, CVE-2022-3171)
• kafka-clients 3.3.2
• lmdbjava 0.8.3

Compatibility

Akka 2.8.x is compatible with Akka 2.7.x and 2.6.x aside from removal of two deprecated modules:

• Classic Remoting transport has been deprecated since Akka 2.6.0 (2019-11-06) and is replaced by the Artery transport, which has been the default since 2.6.0 and declared ready for production in Akka 2.5.22 (2019-04-03).
• OSGi packaging and support in Akka has been dropped.

By compatible, we mean:

• Akka 2.8.x is binary backwards compatible with 2.7.x and 2.6.x, i.e. a library built with Akka 2.6.x can still be used with an application using Akka 2.8.x.
• No configuration changes are needed for updating an application from Akka 2.6.x or 2.7.x to 2.8.x.
• Rolling update of Akka Cluster from Akka 2.6.x or 2.7.x to 2.8.x is fully supported.

Other modules included in Akka 23.05 are also compatible with their previous version.

Detailed release notes:

• Akka (core) 2.8.x
• Akka HTTP 10.5.x
• Akka gRPC 2.3.x
• Akka Management 1.3.x and 1.4.x
• Alpakka Kafka 4.0.1 and 4.0.2
• Alpakka 6.0.x
• Akka Persistence R2DBC 1.1.x
• Akka Persistence JDBC 5.2.1
• Akka Persistence Cassandra 1.1.1
• Akka Projections 1.4.x
• Akka Diagnostics 2.0.x

Akka licensing and support options are available from Lightbend.

Happy hakking!

– The Akka Team