Support Mono Runtime (especially for Unity Server-side use cases)

[hotrhino]

Hello NATS.Net team and community,

I am exploring using NATS.Net within a Unity project, specifically for building a dedicated game server that runs on Mono runtime (typically on Linux). I believe supporting Mono officially would make this excellent library accessible to a significantly larger developer community.

1. The Reality & Need:
   A substantial portion of the game development industry uses Unity. While client builds target various platforms, it's a very common practice to build headless Linux server binaries from the same Unity project using Mono as the scripting backend. These servers handle game logic, state management, and real-time communication. NATS’s performance and pub/sub model would be a fantastic fit for this architecture.

2. Current Hurdle:
   During integration attempts, I encountered challenges getting the NATS.Net library to work seamlessly in the Mono environment built by Unity. This often relates to conditional compilation, runtime compatibility, or dependency issues that are specific to Unity's build pipeline and Mono runtime. While the library mentions Unity support, clear guidance or configuration for this server-side Mono use case seems to be lacking.

3. The Request:
   Could the NATS.Net team consider officially supporting and testing against the Mono runtime, particularly in the context of Unity headless server builds? This could involve:

Adding and maintaining Unity (Mono) as a tested target in the compatibility list.

Providing guidance or a sample on how to integrate the library into a Unity project for a server-only build (e.g., handling DLLs, conditional compilation, recommended build settings).

Ensuring all dependencies are compatible with Mono's sometimes slightly older .NET profile.

4. Community Benefit:
   This support would unlock NATS for countless Unity-based server projects, ranging from indie games to large-scale multiplayer services. The simplicity and performance of NATS align perfectly with the needs of real-time game servers.

Thank you for your time and consideration. I’m eager to hear thoughts from both the maintainers and other developers who might have similar needs or workarounds.

[mtmk]

thank you @hotrhino, I would be very much in favor of this since I feel this would make our Unity support more stable. Although I must mention I am not a Unity or Mono expert, not even close. so I would be relying on the community for this a lot! cc @galvesribeiro

[galvesribeiro]

What issues exactly are you facing @hotrhino? I use NATS myself in games, including Unity. I added the support on NATS with @mtmk specifically for a .Net profile that works well on Unity while keeping the modern .Net API surface, which is netstandard2.1.

Can you elaborate more on what you are facing? There are no explicit .Net moniker to target Mono and the one we've pick works pretty well.

I've built a whole MMO server for a game which had NATS for the backbone of the networking packets. And here I'm talking about the game server, which includes the simulation, and not just a backend of services (i.e. inventory, accounting, etc.).

Note for the future: It is very likely that this will break as Unity versions evolve even before they get into (finally) support the .Net runtime properly. So YMMV depending on the Unity version you are, or will be using.

[hotrhino]

Thank you @galvesribeiro , my colleague from the client-side team has successfully integrated Nats.Net into our system long ago. We are using IL2CPP, and I'm not entirely familiar with the integration details (I'm responsible for the server side, and I don't have much experience with Unity). It seems they utilized NuGetForUnity
for the integration.

On our side, the backend is primarily built using Go, and we've implemented an RPC system with Nats. It's running very well, with a cluster of 9 nodes, and a peak message rate of 25K messages per second per node. The peak traffic is 40MB/s in and 45MB/s out per node.

When I reached out earlier, I was working on integrating Nats.Net for a C# UGC server to incorporate it into our existing server architecture. At that time, I encountered numerous errors, but fortunately, my colleague from the client-side team provided excellent support.

Apologies for the delay in my response. Since we've been able to use other tools for the integration, I’ll be closing this discussion shortly.

[mtmk]

hey @hotrhino thanks for getting back. Glad to see you're using NATS and happy with it. Please do let us know if you have more questions. cheers!