[cortesoft]

Those first two options add more complexity than just using an external database.

I guess I am just not used to downtime being acceptable. Spent most of my career working for a CDN, any sort of downtime was simply unacceptable. I can't stop myself from that sort of thinking now.

[franga2000]

It's complexity you already have. You need some sort of HA for your app server and some sort of resilient storage for your database server. Using sqlite just means the storage is used by the app server directly, nothing more.