Hi there,

I'm in a customer and we thought that using the In-Memory Storage Engine would be a nice feature to use (https://jira.mongodb.org/browse/HELP-1834).

After reading the documentation, we thought only application data is not persisted to disk and it's gone after restarts. What we didn't expect was that authentication and authorization (meta)data was going to be lost as well.

I think it could be helpful to highlight that not only data, but metadata stored in MongoDB (such as authentication and authorization), will be gone after restarting the instance.