AC: Collaboration Engine Clustering Support

[Peppe]

Description

Be able to integrate Collaboration Engine with an existing backend within the Vaadin application. Collaboration Engine can be configured to use a local in-memory backend in development mode while using a cluster-ready backend integration in production. This enables to have use of Collaboration Engine in deployments where the deployed application is replicated on multiple servers. Today with clustered servers and Collaboration Engine running in-memory on each server, a user would only see the users on the same server, and not everyone, which is not acceptable.

Use cases

As a developer
I want to make Collaboration Engine work with clustered server deployment
So that end-users can see each other when they are connected to separate servers

As a business owner
I want to count each person in CE only once, even if they use multiple of our Vaadin projects
So that I don't have to pay multiple times per the same user.

As a dev-ops
I want to manage the CE license and stats in a one place
So that I don't have to manage licenses and stats on every installation of the app, like multiple app installations or installations done on customer premises, and instead can do it once on a central CE server.

Acceptance criteria

• Vaadin applications with Collaboration Engine provide separate backend support to use in a cluster with multiple application server nodes
• Collaboration Engine users see each other when the app is deployed in a cluster and users are on different servers
• Enable delegating access control checks to a service layer.
• All existing Collaboration Engine features should work with a separate server.
• You can still use the in-memory option without extra setup

General criteria

• APIs reviewed

• Design

• Performance

• UX/DX tests in Alpha

• Documentation:

• How to test?

• Limitations: