UNDER_MAINTENANCE state while maintenance is in progress.
///
///
///
/// HEALTHY and UNHEALTHY
/// states. Otherwise, an InvalidStateException is thrown. A ResourceNotFoundException
/// is thrown when the server does not exist. A ValidationException is raised
/// when parameters of the request are not valid.
/// Attributes accepted in a StartMaintenance request for Chef /// /// ///
CHEF_MAJOR_UPGRADE: If a Chef Automate server is eligible for upgrade
/// to Chef Automate 2, add this engine attribute to a StartMaintenance request
/// and set the value to true to upgrade the server to Chef Automate 2. For
/// more information, see Upgrade
/// an AWS OpsWorks for Chef Automate Server to Chef Automate 2.
///