justinhj / akka-persistence-redis

#Akka Persistence Redis Plugin

What is Akka Persistence Redis plugin?

This is a plugin for Akka Persistence that uses Redis as backend.

Compatibility

This plugin was developed for Akka 2.3.x and Scala 2.11.x It uses rediscala, an asynchronous Redis client written with Akka and Scala. Deprecated methods since Akka 2.3.4 are NOT implemented. As a result, some tests in TCK fail. Rest of methods are tested with the test harness included in this project.

Quick start guide

Installation

build.sbt

resolvers += Resolver.jcenterRepo // Adds Bintray to resolvers for akka-persistence-redis and rediscala
libraryDependencies ++= Seq("com.hootsuite" %% "akka-persistence-redis" % "0.2.1")

Activation

akka.persistence.journal.plugin = "akka-persistence-redis.journal"
akka.persistence.snapshot-store.plugin = "akka-persistence-redis.snapshot"

Redis config

From rediscala

redis {
  host = "localhost"
  port = 6379
}

Usage

Redis keys

Journal and snapshot use "journal:" and "snapshot:" as part of keys respectively as it is a good practice to create namespace for keys reference

How is data stored in Redis?

In order to enforce ordering, journal entries and snapshots are inserted into Sorted Set and sorted by sequenceNr

Using custom ExecutionContext

By default, global ExecutionContext is used for Redis operation. This blocks calling thread for synchronous Akka Persistence APIs. Override JournalExecutionContext trait to use custom thread pool if blocking in global is undesirable.

trait CustomExecutionContext extends JournalExecutionContext {
  override implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(Executors.newSingleThreadExecutor())
}

How to contribute

Contribute by submitting a PR and a bug report in GitHub.

Maintainer

Steve Song @ssongvan