This resource represents a collection of all the server machines that have been registered with the site. It other words, it represents the total computing power of your site. A site will continue to run as long as there is one server machine online.
For a server machine to start hosting GIS services, it must be grouped (or clustered). When you create a new site, a cluster called ‘default’ is created for you.
Clusters have been deprecated. The use of clusters for new deployments is strongly discouraged and existing deployments are advised to migrate away from use of clusters as part of ongoing maintenance and upgrades.
The list of server machines in your site can be dynamic. You can register additional server machines when you need to increase the computing power of your site or unregister them if you no longer need them.
The response format. The default response format is html.
Values: html | json
"machines": [ <machine1>, <machine2>, ...]