MrOnyancha / akka-cluster-with-docker

Cluster Demo with Docker

This is a Akka demo application and cluster configuration intended to help understand how Akka clustering works in practice.

It uses Docker to run cluster nodes and iptables to simulate network partitions. Some other failure simulations can also be achieved by killing/pausing/stopping individual docker containers.

Each sample application logs its cluster status events into a file to the mounted folder cluster/events.

1. Build application

cd akka-apps
./build

2. Run cluster

cd cluster

./up <config file>

e.g. ./up configs/sbr-keep-majority.conf

Cluster topology

cd cluster

Run cluster nodes

./up config/sbr-keep-majority.conf ./up config/sbr-keep-oldest.conf

Shutdown cluster nodes

./down

Emulate partitioning between nodes 1 and 3

./connectivity off 1 3

Restore connectivity between nodes 1 and 3

./connectivity on 1 3

Clean up all iptable restrictions for node 4

./clear-rules 4

Connect to node 5

./console 5

Emulate network partitioning (1 2) (3 4 5)

./connectivity-12-345 off

Pause/unpause/restart indiviual node 4

docker-compose pause node-4 docker-compose unpause node-4 docker-compose stop node-4 docker-compose start node-4 docker-compose restart node-4

Akka Management HTTP endpoint

docker-compose exec node-1 curl node-2:8558/cluster/members

or

curl localhost:8558/node-2/cluster/members

See https://developer.lightbend.com/docs/akka-management/current/cluster-http-management.html for more information.

in the latest case control-node provides proxy access by Nginx to each node Akka Management HTTP endpoint. See cluster/control-node for details.