E2E | Notion

🦒 Polling

Polling is a method where the client (browser) continuously checks the server for updates, like chats and dashboards.

🔁 Polling Techniques

Type	Description	Pros	Cons
Short Polling	Client sends requests at fixed intervals (e.g., every few seconds). Server responds immediately—even with no new data.	Simple to implement	High network/server load / battery drain
Long Polling	Client sends a request and waits until the server responds with data. Then sends another request immediately after.	lower latency [fresher data]	More complex to set up

🧠 Best Practices

Use Long Polling or Adaptive Intervals
Fallback Strategies WebSockets or SSE.
Visual Feedback : Show loading indicators or timestamps to shown data

🌐 Alternatives to Polling

Server-Sent Events (SSE) uses a One-way connection: server → client to send data
- Great for live news feeds or stock tickers
WebSockets Bi-directional real time communication over a single TCP connection. Ideal for chat apps, gaming, and collaborative tools

📤 Server Sent Events

SSE is a browser-native technology [EventSource API]

SSE uses a long-lived HTTP connection, unlike WebSockets which use separate protocol wss://
Browser opens an HTTP connection with EventSource object. Server sends updates using text/event-stream format.
Browser automatically reconnects if the connection drops.

🥣 Websockets