I get this error intermittently in my WordPress website hosted on Digital Ocean with a LiteSpeed server. When the site works, it's just fine, but when it doesn't work it keeps giving this error for few minute. Error establishing a database connection This either means that the username and password information in your wp-config.php file is incorrect or that contact with the database server at localhost could not be established. This could mean your host’s database server is down. Are you sure you have the correct username and password? Are you sure you have typed the correct hostname? Are you sure the database server is running?