Background Workers

To keep the primary API fast and responsive, tasks that do not need to block the HTTP/WebSocket response cycle are offloaded to background workers.

Types of Workers

Nyx currently utilizes background processing for the following tasks:

1. Presence Pruning: A periodic job that sweeps the Redis conversationConnections sets. It removes stale connection references (e.g., if a server node crashed and didn't gracefully close its sockets) and recalculates the conversationUsers online counts to ensure absolute accuracy.
2. Delivery Replays: If a user connects to a room and has pending "Sent" messages that haven't been marked as "Delivered", a background routine fetches these from Postgres and re-emits them to the newly connected socket.

Implementation Details

Workers are initialized during the main Bun application boot process (usually inside src/main.ts or triggered via setInterval in the realtime.ts bridge).

Because Nyx runs in a distributed environment, care must be taken to ensure workers do not conflict:

• Stateless Jobs: Tasks like Presence Pruning are safe to run concurrently across nodes because Redis operations (like SREM and HINCRBY) are atomic.
• Node-Specific Jobs: Delivery replays are tied specifically to the node that currently holds the active WebSocket connection.