contains a Settings.xml file, that can specify parameters for the service

Configuration packages describe user-defined, application-overridable configuration settings (sections of key-value pairs)
required for running service replicas/instances of service types specified in the ser-vice manifest. The configuration settings 
must be stored in Settings.xml in the config package folder. 

The service developer uses Service Fabric APIs to locate the package folders and read applica-tion-overridable configuration settings.
The service developer can also register callbacks that are in-voked when any of the configuration packages specified in the
service manifest are upgraded and re-reads new configuration settings inside that callback. 

This means that Service Fabric will not recycle EXEs and DLLHOSTs specified in the host and support packages when
configuration packages are up-graded.