Overview

The Alpakka project is an open source initiative to implement stream-aware and reactive integration pipelines for Java and Scala. It is built on top of Akka Streams, and has been designed from the ground up to understand streaming natively and provide a DSL for reactive and stream-oriented programming, with built-in support for backpressure. Akka Streams is a Reactive Streams and JDK 9+ java.util.concurrent.Flow-compliant implementation and therefore fully interoperable with other implementations.

This Alpakka Kafka connector lets you connect Apache Kafka to Akka Streams. It was formerly known as Akka Streams Kafka and even Reactive Kafka.

Project Info

Project Info: Alpakka Kafka
Artifact	com.typesafe.akka akka-stream-kafka 1.0.5 Snapshots are available
JDK versions	Adopt OpenJDK 8 with Hotspot Adopt OpenJDK 11 with Hotspot
Scala versions	2.12.8, 2.11.12, 2.13.0
JPMS module name	akka.stream.alpakka.kafka
License	Apache-2.0
Readiness level	Supported, Lightbend Platform Subscription provides support Since 0.16, 2017-05-02
Home page	https://doc.akka.io/docs/alpakka-kafka/current
API documentation	API (Scaladoc)
Forums	Lightbend Discuss akka/alpakka-kafka Gitter channel
Release notes	In the documentation
Issues	Github issues
Sources	https://github.com/akka/alpakka-kafka

Matching Kafka Versions

Kafka client	Scala Versions	Akka version	Alpakka Kafka Connector
2.1.1	2.13, 2.12, 2.11	2.5.x	release 1.0.4
2.1.1	2.12, 2.11	2.5.x	release 1.0.1
2.1.0	2.12, 2.11	2.5.x	release 1.0
2.0.x	2.12, 2.11	2.5.x	release 1.0-M1
1.1.x	2.12, 2.11	2.5.x	release 0.20+
1.0.x	2.12, 2.11	2.5.x	release 0.20+
0.11.x	2.12, 2.11	2.5.x	release 0.19

Note

As Kakfka’s client protocol negotiates the version to use with the Kafka broker, you may use a Kafka client version that is different than the Kafka broker’s version.

These client can communicate with brokers that are version 0.10.0 or newer. Older or newer brokers may not support certain features. For example, 0.10.0 brokers do not support offsetsForTimes, because this feature was added in version 0.10.1. You will receive an UnsupportedVersionException when invoking an API that is not available on the running broker version.

– Javadoc for KafkaConsumer

Dependencies

Maven

<dependency>
  <groupId>com.typesafe.akka</groupId>
  <artifactId>akka-stream-kafka_2.12</artifactId>
  <version>1.0.5</version>
</dependency>

sbt

libraryDependencies += "com.typesafe.akka" %% "akka-stream-kafka" % "1.0.5"

Gradle

dependencies {
  compile group: 'com.typesafe.akka', name: 'akka-stream-kafka_2.12', version: '1.0.5'
}

This connector depends on Akka 2.5.x and note that it is important that all akka-* dependencies are in the same version, so it is recommended to depend on them explicitly to avoid problems with transient dependencies causing an unlucky mix of versions.

The table below shows Alpakka Kafka’s direct dependencies and the second tab shows all libraries it depends on transitively.

Direct dependencies

Organization	Artifact	Version	License
com.typesafe.akka	akka-stream_2.12	2.5.23	Apache License, Version 2.0
org.apache.kafka	kafka-clients	2.1.1	The Apache Software License, Version 2.0
org.scala-lang.modules	scala-collection-compat_2.12	2.1.1	Apache-2.0
org.scala-lang	scala-library	2.12.8	Apache-2.0

Dependency tree

com.typesafe.akka    akka-stream_2.12    2.5.23    Apache License, Version 2.0
    com.typesafe.akka    akka-actor_2.12    2.5.23    Apache License, Version 2.0
        com.typesafe    config    1.3.3    Apache License, Version 2.0
        org.scala-lang.modules    scala-java8-compat_2.12    0.8.0    BSD 3-clause
            org.scala-lang    scala-library    2.12.8    Apache-2.0
        org.scala-lang    scala-library    2.12.8    Apache-2.0
    com.typesafe.akka    akka-protobuf_2.12    2.5.23    Apache License, Version 2.0
        org.scala-lang    scala-library    2.12.8    Apache-2.0
    com.typesafe    ssl-config-core_2.12    0.3.7    Apache-2.0
        com.typesafe    config    1.3.3    Apache License, Version 2.0
        org.scala-lang.modules    scala-parser-combinators_2.12    1.1.1    BSD 3-clause
            org.scala-lang    scala-library    2.12.8    Apache-2.0
        org.scala-lang    scala-library    2.12.8    Apache-2.0
    org.reactivestreams    reactive-streams    1.0.2    CC0
    org.scala-lang    scala-library    2.12.8    Apache-2.0
org.apache.kafka    kafka-clients    2.1.1    The Apache Software License, Version 2.0
    com.github.luben    zstd-jni    1.3.7-1    BSD 2-Clause License
    org.lz4    lz4-java    1.5.0    The Apache Software License, Version 2.0
    org.slf4j    slf4j-api    1.7.25    MIT License
    org.xerial.snappy    snappy-java    1.1.7.2    The Apache Software License, Version 2.0
org.scala-lang.modules    scala-collection-compat_2.12    2.1.1    Apache-2.0
    org.scala-lang    scala-library    2.12.8    Apache-2.0
org.scala-lang    scala-library    2.12.8    Apache-2.0

Akka Streams 2.5.23 documentation and sources
Apache Kafka client 2.1.1 documentation and sources

Scala and Java APIs

There are two separate packages named akka.kafka.scaladsl and akka.kafka.docs.javadsl with the API for Scala and Java. These packages contain Producer and Consumer classes with factory methods for the various Akka Streams Flow, Sink and Source that are producing or consuming messages to/from Kafka.

Contributing

Please feel free to contribute to Alpakka and the Alpakka Kafka connector by reporting issues you identify, or by suggesting changes to the code. Please refer to our contributing instructions to learn how it can be done.

We want Akka and Alpakka to strive in a welcoming and open atmosphere and expect all contributors to respect our code of conduct.