Scalable Viewer Distribution with PipeTransport

[Harxhit]

Goal

Implement scalable live-stream viewer distribution using MediaSoup PipeTransport and worker-aware router selection.

Current Architecture

• Single Worker
• Single Router
• Broadcaster produces audio/video
• Viewers consume directly from same Router

Target Architecture

Main Broadcaster
       │
   Router A
(Ingress Router)
       │
 ┌─────┼─────┐
 │     │     │
 ▼     ▼     ▼
Router B Router C Router D

• Router A hosts broadcasters/co-hosts.
• Viewer routers (B/C/D) host consumers only.
• Producers are piped from Router A to viewer routers.
• Viewers are assigned based on worker load.

Tasks

Worker Load Tracking

• Track worker CPU usage.
• Track router count per worker.
• Track transport count per worker.
• Track consumer count per worker.
• Expose worker metrics for debugging.

Router Selection

• Implement least-loaded worker selection.
• Create viewer router on selected worker if needed.
• Add router assignment strategy abstraction.

PipeTransport Infrastructure

• Research router.pipeToRouter().
• Understand PipeProducer lifecycle.
• Understand PipeConsumer lifecycle.
• Handle router close events.
• Handle worker crash scenarios.

Live Session Registry

• Store ingress router ID.
• Store broadcaster producer IDs.
• Store co-host producer IDs.
• Track piped routers.
• Prevent duplicate piping.

Example:

{
  ingressRouterId,
  producerIds,
  pipedRouters
}

Viewer Join Flow

• Select least-loaded worker.
• Resolve target router.
• Pipe producers if router is not already piped.
• Create consumer transport.
• Create consumers from PipeProducers.

Producer Synchronization

• When broadcaster starts video, pipe to all viewer routers.
• When broadcaster starts audio, pipe to all viewer routers.
• When co-host joins, pipe new producers.
• When producer closes, cleanup PipeProducers.

Metrics & Logging

• Log router creation.
• Log pipe creation.
• Log worker load.
• Log viewer router assignment.
• Log active viewers per router.
• Log active PipeProducers.

Future Investigation

• Multi-worker architecture.
• Multi-router architecture.
• Cross-server scaling.
• Geo-distributed viewer routing.
• Autoscaling based on worker load.

Docs to refer

https://mediasoup.org/documentation/v3/mediasoup/api/?utm_source=chatgpt.com#RouterOptions