What is WS/WSS?
WebSocket (WS) is a protocol that provides full-duplex communication channels over a single TCP connection.
WebSocket facilitates data exchange between the client and server, and allows active data push from the server to client. In WebSocket API, only one handshake is required between the browser and server to create a persistent connection and carry out bi-directional data transmission.
Why should WS/WSS be used?
Without WebSocket, the client has to pull data from the server through polling.
There are two shortcomings in this data exchange method:
1. Low efficiency. To pull real-time data, the client has to frequently initiate the Ajax request.
2. The server cannot push data proactively.
WebSocket is designed to solve these problems. As a new protocol released when HTML5 was launched, WebSocket achieves full-duplex communication between the browser and server. It can transmit message-based text and binary data, solving HTTP problems at the protocol level.
Key advantages of WebSocket:
1. Less overhead. After the connection is established, the packet header used for control is small. Compared to an HTTP request that requires a complete header, WebSocket helps reduce the overhead.
2. Real-time push. As a full-duplex protocol, WebSocket can achieve real-time data push from server to client.
3. Persistent connection.
How is WS/WSS billed?
CLB supports WS/WSS by default and no additional fees will be charged.
How do I enable WS/WSS for CLB?
WS
/WSS is enabled for CLB by default. If a connection is idle for more than 60s, you need to customize the proxy_read_timeout parameter, which should be less than 900s preferably. For more information, see Layer-7 Custom Configuration. If the listener listens to HTTP or TCP SSL, WS is supported by default. If it listens to HTTPS, WSS is supported by default.
When WSS is used, CLB will carry out SSL offloading.
If the listener is configured for HTTPS or TCP SSL, WSS is supported by default. CLB will complete SSL offloading before forwarding the traffic.
Which regions support WS/WSS?
Currently, WS/WSS protocols are supported in all regions.