Conflict Resolution

Distributed systems are messy. Two users might edit the same document while offline. How do we decide who wins?

Last-Write-Wins (LWW)

GoSync currently uses a Last-Write-Wins strategy based on high-precision timestamps.

How It Works

  1. User A changes Title to "Draft" at 10:00:01.000
  2. User B changes Title to "Final" at 10:00:05.000
  3. Result: "Final" wins. User A's edit is overwritten.
javascript
// Both versions arrive at the server
const versionA = { title: "Draft", updated_at: "2024-01-01T10:00:01.000Z" };
const versionB = { title: "Final", updated_at: "2024-01-01T10:00:05.000Z" };

// GoSync compares timestamps
// versionB.updated_at > versionA.updated_at
// Winner: versionB

Why LWW?

  • Simplicity: It requires zero configuration from you.
  • Predictability: The latest action is usually the "correct" one for most CRUD apps (To-Do lists, Settings, Inventory).
  • Performance: No complex merge algorithms needed.

Handling Conflicts in Your App

While GoSync handles the technical merge, you might want to notify users when their changes were overwritten.

javascript
GoSync.onConflict('todos', (local, remote, winner) => {
  if (winner === 'remote') {
    toast.warn('Your changes were overwritten by a newer version');
  }
});

Timestamp Precision

GoSync uses millisecond-precision ISO 8601 timestamps. Make sure your client always includes the updated_at field:

javascript
const item = {
  id: 'uuid-1234',
  title: 'My Task',
  updated_at: new Date().toISOString() // "2024-01-01T10:00:01.123Z"
};

Tip: If two changes have the exact same timestamp (extremely rare), the server breaks the tie using the item's id alphabetically.

Future Roadmap

Coming Soon: We are researching CRDTs (Conflict-free Replicated Data Types) for future versions to support collaborative text editing (Google Docs style).

← Back to Introduction