odoo deployment in auto-scaling scenario

I am trying to understand how to prepare a fresh server to deploy into a currently running cluster. Or as a replacement for a failed instance.

Other than the content of the source distribution (plus any added custom resources), what else needs to be deployed?

I have discovered images being served from the 'data_dir' filestore. Some resources like fontawesome files and certain icons are not being served.

Should the 'data_dir' location be shared between multiple instances in a cluster? And should it survive server failures?

Any other tips also appreciated?