HTTP 101 Switching Protocols vs 411 Length Required
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 411 (Length Required) is a 4xx Client Error response. 101 indicates that the server understands the Upgrade header field request and indicates which protocol it is switching to. In contrast, 411 means that the server refuses to accept the request without a Content-Length header.
Описание
The server understands the Upgrade header field request and indicates which protocol it is switching to.
Когда вы это видите
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
Как исправить
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
Описание
The server refuses to accept the request without a Content-Length header.
Когда вы это видите
When sending a request body without specifying Content-Length.
Как исправить
Include a Content-Length header in your request.
Ключевые различия
101 is a 1xx Informational response, while 411 is a 4xx Client Error response.
HTTP 101: The server understands the Upgrade header field request and indicates which protocol it is switching to.
HTTP 411: The server refuses to accept the request without a Content-Length header.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 411 when when sending a request body without specifying Content-Length.
Когда что использовать
For 101 (Switching Protocols): This is normal behavior during protocol upgrades. Ensure your client supports the target protocol. For 411 (Length Required): Include a Content-Length header in your request.