Accepted: Benchmarking Network Performance for Scalable Multiplayer in Godot

Metadata

  • Status: Proposed
  • Deciders: V-Sekai Team, Bioblaze Payne, fire
  • Tags: Networking, Performance, Godot Engine, V-Sekai, Test

The Backdrop

In the pursuit of optimizing network performance for the V-Sekai project, we’re at a point where we need to evaluate different networking strategies provided by the Godot Engine.

The Challenge

Design a comprehensive series of tests to measure and compare the performance of the three different networked multiplayer strategies within the Godot Engine:

  1. The many servers approach: A decentralized model where numerous smaller servers handle subsets of users.
  2. The many worlds approach: A single server hosts multiple distinct world instances.
  3. The one world with threaded process group nodes: A monolithic single world that leverages threading to manage users and activities.

The Strategy

The testing was suggested by Bioblaze Payne, who has outlined a sequential approach:

  • Phase 1: Basic Connection Test
    • Connect a user, send a message, await 1000 messages in return, disconnect, then reconnect.
  • Phase 2: Large Scale Stress Test
    • Simultaneously connect 4000 users, with each sending a message upon connection every 500ms. Ensure all messages are replicated to all connected clients.

During these tests, we’ll monitor:

  • Load times for initial connections and reconnections.
  • Throughput and latency of message delivery.
  • Server resource usage (CPU, RAM, Network I/O).
  • Any errors or dropped connections that occur.

All relevant events should be timestamped and logged to a centralized logging system for analysis.

The Upside

By conducting this research, we aim to:

  • Identify the most scalable and efficient networking strategy for the V-Sekai project.
  • Gather empirical data to inform future development decisions.
  • Contribute findings back to the wider Godot community to aid in similar multiplayer projects.

The Downside

Potential risks and drawbacks include:

  • Time and resources required for test setup and execution.
  • Interpretation of results may vary, leading to indecision.
  • Possible discovery of fundamental issues that could delay project timelines.

The Road Not Taken

This section will detail alternative methods and practices considered but ultimately not chosen, with justifications for their exclusion.

The Infrequent Use Case

We will also explore less common user scenarios that may have unique performance characteristics under each networking strategy.

In Core and Done by Us?

Discussion on whether the outcomes of this initiative should be integrated into the core V-Sekai codebase or maintained as separate modules.

Further Reading

  1. V-Sekai · GitHub - Official GitHub account for the V-Sekai development community focusing on social VR functionality for the Godot Engine.
  2. V-Sekai/v-sekai-game - GitHub page for the V-Sekai open-source project bringing social VR/VRSNS/metaverse components to the Godot Engine.

This design document was completed with assistance from AI developer Aria.