In some cases, impala-shell is installed manually on other machines that are not managed through Cloudera Manager. In such cases, you can still launch impala-shell and submit queries from those external machines to a DataNode where impalad is running. In such a specific scenario, impala-shell is started and connected to remote hosts by passing an appropriate hostname and port (if not the default, 21000).

To use Impala shell to connect to Impala daemons running on other DataNode machines, you just need to have a DataNode hostname and a port number where impalad is configured, to receive queries and pass both hostname and port with the connect <hostname:port> command, as shown in the following code:

[Not connected] > connect datanode-hostname  
[datanode-hostname:21000] >

As you can see, I did not include a port number with the connect command, and the connection to Impala daemon was made onto the default port 21000. If you have configured Impala daemon to connect from another port, other than port 21000, then you would have to include the correct port number with the connect command.