Infrastructure Audit: Zone Tokens & Tick Sync

Zone Token TTL

Mechanism

• Tokens are created with a timestamp.
• TOKEN_EXPIRY_SECONDS is set to 60 seconds.
• validate() method explicitly checks:

  if now - self.timestamp > Self::TOKEN_EXPIRY_SECONDS {
     anyhow::bail!("Transfer token expired");
  }

• Redis is used for Anti-Replay (tokens are deleted after use).
• Redis keys also have a TTL (SETEX) to auto-expire unused tokens.

Client Tick Drift

Problem

• Server runs strict 600ms ticks.
• Client attempts to run at 600ms but relies on requestAnimationFrame or setTimeout which are subject to browser throttling and lag.
• Over time, or during lag spikes, the client's tick count desynchronizes from the server's.

Consequences

• Animations may play out of sync.
• Prediction logic (where client predicts movement) may be corrected by server "snaps" (rubber-banding).
• Timers on client (e.g., potion duration) may drift from server reality.

Recommended Fix (Future Work)

1. Server includes server_tick in every GamePacket.
2. Client adjusts its local client_tick to match server_tick if drift > 1 tick.
3. Client speeds up or slows down loop to catch up smoothly (tick rate adjustment).