Rouille: ConnectionReset, message: "Connection reset by peer"

Hi,

This is more of a conceptual question rather that "code help". So I am trying out two example form ruuille crate :

database
login

when I leave them running for a while the database example resets itself so when i try to call GET i receive: Error(Io(Os { code: 104, kind: ConnectionReset, message: "Connection reset by peer" })) but the login example does not. My question is why? Is it because it is connected to the database ? does this usually happen with apps that are communicating with a database?