已经有一些树莓派组集群的教程
http://shumeipai.nxez.com/2019/03/18/build-your-serverless-raspberry-pi-cluster-with-docker.html
http://shumeipai.nxez.com/2013/11/04/raspberry-pi-build-hadoop-cluster.html
http://shumeipai.nxez.com/2014/01/09/raspberry-pi-from-the-32-built-supercomputer.html
http://shumeipai.nxez.com/2016/02/13/raspberry-pi-zero-cluster-in-development.html
200-300个树莓派也就是一个局域网段能搞定的数量。