Quicker iteration during development
When developing multiplayer experiences you will need to run multiple instances of your game in order to test properly. You also need to make sure these instances can be restarted quickly, so you can iterate quickly.
coherence does not have a built-in solution for multiclient testing, but there are several options available to you, each with their own benefits and drawbacks.
ParrelSync is an open-source project which allows you to have multiple Editors open which share Assets and ProjectSettings using Symbolic links.
Benefits
Short iteration times.
Easily debuggable instances.
Drawbacks
Requires you to have multiple Editors open.
Caveats
All instances of the game must have identical schemas, which are NOT shared using ParrelSync. That means you need to bake on all open Editors. Setting Auto Bake on Enter Play Mode to true in coherence Settings will alleviate this issue.
EditorPrefs are not consistently shared between Editors.
First, install the ParrelSync package as described in the Installation Instructions.
Open ParrelSync -> Clones Manager. Create a new clone, and open it.
Continue development in the original Editor.
When you need to test, do the following for all open Editors: Bake, press play. Alternatively you can set Auto Bake on Enter Play Mode to true.
The easiest method is to simply create a new build each time you want to test anything. You can launch any number of instances of that build, and have an instance running in the Editor as well.
Benefits
Easy to distribute amongst team members.
Well-understood workflow.
Drawbacks
Long iteration time as you need to continuously make builds.
Harder to debug the executables.
Caveats
All instances of the game must have identical schemas, so remember to bake before building the executable.
Unity has an experimental package called Multiplayer Play Mode (MPPM) available for 2023.1. As this is currently experimental, we do not officially recommend it - but it does show some promise and should be mentioned. This package allows a single Editor to run several instances of a game.
Benefits
Short iteration times.
No issues with schema incompatibility.
Drawbacks
Experimental.