JoinQueue

Versions: NeoForge 1.21.1 & 1.21.8

Prevents server crashes and TPS drops caused by many players joining at the same time (e.g., after a restart or during events). The mod puts connecting players into a waiting line during the Configuration Phase, preventing the Main Thread from overloading.

Features

Activation: The queue starts when the player count reaches a threshold (default: 20), when TPS drops below 8.0, or during a grace period after server start.
TPS Check: Players are only let in when the server is stable (TPS ≥ 15.0). The queue pauses automatically during heavy lag.
Manual Control: Admins can use /joinqueue pause and /joinqueue resume to stop or start the login process manually.
Priority & Bypass:
- Staff members bypass the queue entirely.
- VIP players are moved to the front of the queue.
Async Chunk Loading: Loads spawn chunks on background threads before a player joins to prevent main thread freezes.
Queue Screen: Shows players their current position in line.

Commands

All settings are saved automatically and take effect immediately.

Command	Description
`/joinqueue status`	Shows TPS, queue size, and current status.
`/joinqueue pause`	Pauses the queue.
`/joinqueue resume`	Resumes the queue.
`/joinqueue list`	Lists all players currently waiting.
`/joinqueue vip <add/remove/list>`	Manages the VIP list.
`/joinqueue staff <add/remove/list>`	Manages the Staff list.

Technical Details

Uses ConcurrentLinkedDeque and AtomicInteger for thread-safe performance.
TPS is measured via a rolling 40-tick ring buffer using nanoTime.
Required on both server and client.

Joinqueue