The application that works behind Confluence Collaborative Editing is called Synchrony. Synchrony works in two modes: Standalone and Managed by Confluence.
Standalone: As the name suggests, it is setup as a standalone cluster which is dedicated for Collaborative Editing.
Managed by Confluence: Synchrony is co-located with Confluence in the same cluster. And it is managed by Confluence.
Personally, I prefer Synchrony that is managed by Confluence. As it simplifies the design and implementation, and it just works! And I believe it is also the recommended solution by Atlassian.
There are basically two types of setup when using Synchrony that is managed by Confluence: synchrony-proxy and direct synchrony access. Let’s have a look the typical traffics flow:
Load Balancer (443) > Reverse Proxy (80) > Confluence (8080) > Synchrony-Proxy > Synchrony
direct synchrony access
Load Balancer (443) > Reverse Proxy (80) > Synchrony (8091)
Obviously, direct synchrony access has shorter path. Shorter path normally means quicker response time, and the following diagram proves it.