My normal combination on the big-server side would be Apache + MySQL (or PostgreSQL), but on the RPi this seems to be absolute overkill. For data-logging operations I would not use the local system anyway (looking at MQTT as well as Remote MongoDB datastore via REST Webservices).

After some poking around and reading up on the options I decided to go for the following combo: LightHTTPD + SQLite. Both are lightweight replacement of their fully-featured big-server counterparts (Apache HTTP & MySQL) and have very familiar configurations. There would be other options that have even less resource usage, but I really don’t have the time to start from scratch somewhere.