SQLite can throw database locked error during write

[adamgreig]

If someone else is reading (or writing) the database when a result comes in over the network, it can't be written as the database is locked. Should really retry or at least catch exception rather than having it kill the server.

[adamgreig]

This is quite probably related to: http://beets.radbox.org/blog/sqlite-nightmare.html

Increasing the timeout should help. Implementing Python-level locks as in the link is difficult as the DB is accessed from multiple processes (e.g. one process loading data to chart while another is still running the server to accept new data).