The hardware elements that we will use are as follows:
- Two laptops as core servers, running Linux, connected to a home WiFi network
- Two raspberry Pi, 2 and 3, running as core servers
Read replica servers will be running as Docker containers. There will be five replicas running on my main laptop.
In a typical deployment, there are more read replicas than core servers. Of course, you can use any machine you want as long as it can connect to a network and run Neo4j. This can be more PCs, Macs, or any brand of credit card-sized computer running Linux.
Here, in a home environment, all servers are on the same network, plugged on the same router, and mostly in the same room (or not because of wifi and long cables). However, it is still relevant as an example and probably one of the cheapest options to do a cluster with hardware.
In a business environment, you may have to talk to your IT service, declare the machines, list which ports they use, and ask for safe passage of the network...