Some more points for consideration from previous post

 Advantages of resource provisioning design:

1.      It enables deployment, scaling, load balancing, logging, and monitoring of all resources both built-in and client authored.

2.      There needs to be only one resource type in the control plane for a new adapter service that stands for the desired device configuration in terms of action and state.  A controller can reconcile the device to its device configuration. There needs to be only one controller for a resource type. The commands, actions and state of a device may be quite involved but the adapter service has a chance to consolidate a logical resource type.

3.      The device statistics can be converted to metrics and monitoring and offloaded for collection and analysis to its own stack. The metrics are pushed from other services. This has an opportunity to use an off the shelf solution. The data in written once but it can be read-only for analysis stacks. The Read-Write and Read-Only separation will help maintain the source of truth.

4.      Separation of control plane and data plane also provides opportunity to use other infrastructure at a later point of time that allows all the services to be cloud friendly and portable.

5.      One of the ways to enforce backward compatibility is to have specific versions for the APIs. In addition to having data syntax and semantics compatibility described via data contracts that can be verified offline via independent tools, it might be helpful to support multiple versions of the service from the start. Exposing resources via Representational State Transfer is a well-known design pattern

6.      The reconciliation of the resource can be achieved with the help of a dedicated controller. A controller for the device control plane resource object is a control loop that watches for the state of the resource and then makes, or request changes as needed. Each controller tries to move the current state to the desired state by reading the spec field associated with the resource object. The control plane resource object can be created, updated or deleted just like any other resource with representational state transfer API design. The controller can set additional states on the resource such as marking it as finished.