Functional overview

The following list provides the salient features of the REST-style APIs:

• Resource-based
• Stateless
• Client/server
• Cacheable
• Layered system

REST is a resource-based service system in which requests are made to the resource’s Universal resources identifier (URI). The request invokes a response from the resource in the JSON format. An IBM Storage Scale management API resource is a collection of all the objects of the same type in a cluster, such as all the filesets. A resource element is an instance of a resource, such as a particular fileset named fileset1. In a REST API request, a resource or a resource followed by a resource element appears as the last term in the request, except for any trailing HTTPS parameters. The following example request ends with a resource, filesets. It indicates that this operation affects all the filesets that are part of a file system named gpfs0:

https://198.51.100.1:443/scalemgmt/v2/filesystems/gpfs0/filesets

In contrast, the following example ends with a resource that is followed by a resource element filesets/fileset1. It indicates an operation that affects this particular fileset, such as creating or deleting the fileset:

https://198.51.100.1:443/scalemgmt/v2/filesystems/gpfs0/filesets/fileset1

The kind of operations that can be performed on the resources or a resource element are directed by the HTTP methods, such as GET, POST, PUT, DELETE. In some cases, the parameters in the HTTPS request also direct the operations. The following list provides the meanings of the basic HTTP methods that are used in the requests:

• GET - Reads a specific resource or a collection of resources and provides the details as the response.
• PUT - Updates a specific resource or a collection of resources.
• DELETE - Removes or deletes a specific resource.
• POST - Creates a resource.