The connection parameters supported by this class are:.
- scheme: it can be either 'redis', 'tcp', 'rediss', 'tls' or 'unix'.
- host: hostname or IP address of the server.
- port: TCP port of the server.
- path: path of a UNIX domain socket when scheme is 'unix'.
- timeout: timeout to perform the connection (default is 5 seconds).
- read_write_timeout: timeout of read / write operations.
- async_connect: performs the connection asynchronously.
- tcp_nodelay: enables or disables Nagle's algorithm for coalescing.
- persistent: the connection is left intact after a GC collection.
- ssl: context options array (see http://php.net/manual/en/context.ssl.php)