It depends on how you have configured your 'Database' rule. If you are using JDBC url to connect to database the connection timeout will be done by the DB server, hence it will be loop hole in the transaction and there may arise security issues. You can probably connect to external database by using JDBC connection pool or use with preferences option on Database rule, which will make sure that whenever the connect-sql is called in RDB-execute method in activity the connection to DB is establised through connection pool.