Tinkering with Akka Cluster
This is a toy application developed to play a bit with Akka Cluster. It is based on the sample repo provided by Akka, and on the official documentation. Do you want to play with it? Feel free to contribute! 😄
The project is "docker-first", so we need to create the docker images to run using sbt Native Packager. Run the command sbt docker:publishLocal, it will create the image elleflorio/akka-cluster-playground.
Once you have the image, type docker-compose up. Docker compose will run a seed node along with node1 and node2.
I integrated Akka HTTP, so you can interact with the cluster using the following REST API. The port for the nodes are the following:
- seed:
8000 - node1:
8001 - node2:
8002
Check if the nodes are up and running calling a /health endpoint:
GET http://localhost:{{port}}/health
Response:
OK
Check the members inside the cluster using the /status/members endpoint:
GET http://localhost:{{port}}/status/members
Response:
[
"akka.tcp://cluster-playground@node1:1600",
"akka.tcp://cluster-playground@node2:1600",
"akka.tcp://cluster-playground@seed:2552"
]
Ask for the computation of Fibonacci number n with the /process/fibonacci/n endpoint:
GET http://localhost:{{port}}/process/fibonacci/10
Response:
{
"nodeId": "seed",
"result": 55
}
The nodeId represents the node where the processor
that executed the computation is running.
The cluster uses Cluster Aware Routers for load balancing, with a round-robin strategy. You can verify this asking for the Fibonacci number computation to a random node. Everytime the nodeId in the response will be different, following a round-robin strategy.
That's it! Enjoy! 😁