It’s really great to hear what a similar system was like in production!
I had considered using Mnesia, as it meets the criteria of being on the BEAM and would provide a lot of the extra control around saving to disk that I would otherwise have to write.
Transactions have become more of a requirement/issue the more I’ve looked into the concept. Guaranteeing that events are written to disk fully means that the entire event store effectively becomes sequential and blocking — unless I’m misunderstanding the fundamental requirements…
I’d very much like to make the file-based event store work, but it’s increasingly looking like PostgreSQL is a far more pragmatic choice.
Seeing as I’m looking at using files for persistence and GenServers for the memory image then perhaps all I’m looking for is a GenServer that can be recovered/restored/rebuilt from file. Something like PersistentGenServer, Mnemonix, or even CacheX? It wouldn’t be ES as commonly practised and more actor model with some events stuffed into it. I’d have to do some thinking on whether this would suit my requirements.
