I quite like immutable infrastructure. It means you have a rollout/roll back with a flip of a dns/connection. However I see a lot of things about docker and th

I quite like immutable infrastructure. It means you have a rollout/roll back with a flip of a dns/connection. However I see a lot of things about docker and think two things: 1) most people really wany a mainframe 2) shared filesystems really are brlilliant. Let me unpack that: a mainframe provides a massive amount of hardware, a hypervisor and scheduler. This means that you can control a bunch of isolated processes through one one system easily. Something that you can't really do in docker yet (fleet/kubernetes arn't there yet. in a mainframe you can use a single script to control an entire system) Quite a lot of web config management is about shipping packages to different machines. Almost all of this config, and therefore complication can be removed by using a shared filesystem. For example we have many version of java. For some reason they are in seperate repos. This means that if you want to change version (openJDK to oracle etc) you have to change config. With a shared file system, in the $PATH, you'd just say oracalejava-1.8 $programme or java-1.7 $programme If you make your deploys to a similar shared filesystem, then to change config is basically a case of ssh machine, kill old process, launche new process. Job done. This makes each machine a dumb execution system, minimal state is contained in each node. With NFS coming to AWS, that'll be the model for my new infrastructure. the reason why? because it works. In HPC thats how we've been managing high scale workloads for years.