HTTP 100 Continue vs 502 Bad Gateway
HTTP 100 (Continue) is a 1xx Informational response, while 502 (Bad Gateway) is a 5xx Server Error response. 100 indicates that the server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected. In contrast, 502 means that the server, acting as a gateway or proxy, received an invalid response from the upstream server.
説明
The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
このコードが表示される場合
When a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
解決方法
This is an interim response — no fix needed. The client should continue sending the request body.
説明
The server, acting as a gateway or proxy, received an invalid response from the upstream server.
このコードが表示される場合
When Nginx/Apache can't reach the application server (e.g., Gunicorn is down, upstream timeout).
解決方法
Check if the upstream server is running. Verify proxy configuration. Check for upstream timeouts.
主な違い
100 is a 1xx Informational response, while 502 is a 5xx Server Error response.
HTTP 100: The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
HTTP 502: The server, acting as a gateway or proxy, received an invalid response from the upstream server.
You encounter 100 when when a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
You encounter 502 when when Nginx/Apache can't reach the application server (e.g., Gunicorn is down, upstream timeout).
どちらをいつ使うか
For 100 (Continue): This is an interim response — no fix needed. The client should continue sending the request body. For 502 (Bad Gateway): Check if the upstream server is running. Verify proxy configuration. Check for upstream timeouts.