This topic provides an overview of listeners. After you create a Classic Load Balancer (CLB) instance, you must configure one or more listeners for it. A listener checks for connection requests and then distributes the requests to backend servers based on the forwarding rules that are defined by a specified scheduling algorithm.
CLB provides Layer 4 (TCP or UDP) and Layer 7 (HTTP or HTTPS) listeners. The following table lists the features and use cases of these listeners.
Protocol | Description | Scenario |
---|---|---|
TCP |
|
For more information, see Add a TCP listener. |
UDP |
| Applicable to scenarios where real-time transmission is more important than reliability, such as video chats and real-time financial market pushes. For more information, see Add a UDP listener. |
HTTP |
| Applicable to scenarios that require data content identification, such as web applications and small mobile games. For more information, see Add an HTTP listener. |
HTTPS |
| Applicable to scenarios that require encrypted transmission. For more information, see Add an HTTPS listener. |