- // Other than mysql_connect, mysqli_real_connect expects an explicit port
- // and socket parameters. So we need to parse the port and socket out of
- // $realServer
+ // Other than mysql_connect, mysqli_real_connect expects an explicit port number
+ // e.g. "localhost:1234" or "127.0.0.1:1234"
+ // or Unix domain socket path
+ // e.g. "localhost:/socket_path" or "localhost:/foo/bar:bar:bar"
+ // colons are known to be used by Google AppEngine,
+ // see <https://cloud.google.com/sql/docs/mysql/connect-app-engine>
+ //
+ // We need to parse the port or socket path out of $realServer