Stop and start hosted services on ArcGIS Server

Summary

Stopping and starting hosted services aren't operations you can perform through ArcGIS Server Manager. This can be done via the ArcGIS Server Administrator Directory.

Procedure

To stop and start hosted services on ArcGIS Server:

1. Navigate and sign in to the ArcGIS Server Administrator Directory. URL should be https://yourdomain.com/arcgis/admin (you may need to sign in with a Portal token if you do not have the built-in ArcGIS Server administrator credentials).
2. Navigate to services > Hosted > yourHostedServiceName.
3. At the very bottom of the page are Supported Operations to start and stop the service, shown in the image below. 

On this page you can also check the current status of the service, view statistics, permissions, and life cycle information.