liauli
commented
1 week ago about tcp/udp: https://any-one-can-code.medium.com/understanding-tcp-udp-http-and-websocket-concepts-part-1-499f9f751c54
From ChatGPT:
Firestore and Real-Time Updates
- WebSocket-Based: Firestore uses WebSockets for its real-time data synchronization. When a client app listens to a document or a collection for changes, it establishes a WebSocket connection with the Firestore backend. This WebSocket connection allows Firestore to push updates to the client instantly whenever the data changes.
- TCP Connection: Since WebSockets operate over TCP, Firestore benefits from TCP's reliability and ordered delivery, ensuring that changes are synchronized accurately without data loss or reordering.
Why Firestore Uses WebSockets Over TCP
- Real-Time Synchronization: WebSockets provide a persistent connection that is ideal for applications like Firestore, where changes in the database need to be reflected in real-time on connected clients.
- Efficient Data Transfer: With WebSockets, Firestore can push updates immediately without requiring the client to repeatedly poll the server for changes, which reduces both latency and bandwidth usage.
- Cross-Platform Compatibility: By using WebSockets, Firestore can provide real-time updates across various environments (web, iOS, Android) while working through firewalls and proxies that support TCP-based WebSocket connections. Summary
Firestore’s real-time capabilities leverage WebSockets over a TCP connection. This allows for reliable, low-latency data synchronization between the Firestore backend and clients, making it an effective solution for applications that require up-to-date data.
Real-Time Listeners
Firestore’s real-time capabilities are provided through listeners. In iOS, you can set up listeners to get live updates when data changes. How it Works:
- You create a listener on a document or collection using addSnapshotListener.
- Firestore opens a WebSocket connection to the server.
- Whenever data changes on the server, the listener updates the local snapshot and triggers an event, letting your app react immediately.
ref: #1