How To Distribute Application State with Akka Cluster

Building, testing, containerizing, deploying, and monitoring distributed microservices is difficult, but using Lightbend technologies can make it a lot faster and easier to be successful. In this four part blog series, we walk you through a working Proof of Concept (PoC) built using Lightbend’s open source distributed toolkit, Akka. This PoC delivers a resilient, highly performant, elastic, distributed, and consistent state solution that provides an automatic in memory cache with a persistent backing. Here is the breakdown:

• Part 1 - Getting Started: we walk through building, testing, and running the PoC locally, with instrumentation and monitoring wired in from the very beginning using Lightbend Telemetry.
• Part 2 - Docker and Local Deploy: here we cover containerizing our PoC, and then deploying locally in Docker. Then, we’ll load test and monitor our PoC as we did in the first installment.
• Part 3 - Kubernetes and Monitoring: in this part,we introduce Lightbend Console for Kubernetes (K8s), and then deploy our PoC in Minikube (desktop version of K8s) using YAML files provided in this repository. Again, we’ll load test with Gatling, but this time we’ll monitor our PoC in Lightbend Console.
• Part 4 - Source Code: In our final installment, we do a deep dive into our Scala source code.

Note: This repoistory is written for Scala developers, a Java version can be found here.

Update September 20, 2022

• updated the branch mread-multi-dc-common-journal, which supports Akka's Replicated Event Sourcing "Common Journal" running on Multi-Data Center / Microk8s and Yugabyte. Updated README.md can be found here.

Update September 15, 2022

• update Akka related dependencies to latest
• Moved to Java 17 base image
• Set up for Akka DNS cluster formation on Docker w/ Yugabyte. Doc here.

Update: April 18, 2022

• Updated Akka, Akka Http, and Akka gRPC dependencies with the latest versions
• recreated the missing gRPC Client (ArtifactStateForEach) example for request / response

Update: February 22, 2022

• Merged PR to include gRPC support even though blog hasn't been updated yet. No ETA on blog update.
• This repo written in Java can be found here.

Update: August 31, 2021

• On Branch: mread-add-grpc-endpoint: updated the instructions for deploying locally on Microk8s.

Update: August 11, 2021

• On Branch: mread-add-grpc-endpoint, which will be merged to master, once we update the blog post
• fix Cassandra v3.11.11 docker-compose files

Update: August 6, 2021

• fixed deprecation warnings

Update: August 5, 2021

• Upgraded all versions of the Lightbend stack's dependencies to the currently released versions.

  • The biggest change revolves around the change of the akka-persistence-cassandra (v0.102 -> v1.0.5), which requires a migration in tables and configuration.
  • Scala: v2.13.1 -> v2.13.6
  • Sbt v1.3.9 -> v1.5.5
  • Akka: v2.6.6 -> v2.6.15
  • Akka Http: v10.1.12 -> v10.2.5
  • Akka Management v1.0.8 -> v1.1.1
  • Lightbend Telemetry -> v2.14.0 -> v2.16.1
  • Java: v8 -> v11

• Microk8s - tested locally on Microk8s, please see microk8s/README.md for more information.

• locked in to cassandra image to: v3.11.11

Update: June 10, 2020

In honor of Lightbend’s release of Akka’s Split Brain Resolver as OSS, I’ve updated this repository to take advantage of Akka 2.6.6.

For more information on Akka Split Brain Resolver please see the announcement here → https://akka.io/blog/news/2020/06/08/akka-2.6.6-released-split-brain-resolver

Also, Patrik Nordwall’s video on Split Brain Resolver is really great in helping you understand why you should care → https://akka.io/blog/news/2020/06/08/akka-split-brain-resolver-video