In this blog post, I’ll show how we can build a three-node cassandra cluster on Docker for testing. I’ll use official cassandra images instead of creating my own images, so all process will take only a few minutes (depending on your network connection). I assume that you have Docker installed on your PC, have internet connection (I was born in 1976 so it’s normal for me to ask this kind of questions) and your PC has at least 8 GB RAM. First of all, we need to assign about 5 GB RAM to Docker (in case it has less RAM assigned), because each node will require 1.5+ GB RAM to work properly.
Open the docker preferences, click the advanced tab, set the memory to 5 GB or more, and click “apply and restart” docker service. Launch a terminal window, run “docker pull cassandra” command to fetch the latest official cassandra image.