Hot Code Loading experiences for APIs

ok thanks so auth on server1→ cookie session is set on client, we use server2 all of a sudden but we sill use that same session and it’s accepted by server1 and server2 because they use the same secret_key?

i remember my elixir phoenix app locking the postgres, how does this work wihen 2 servers connect to the same postgres? arent they both try to lock the tables they work with? thanks!!