proxy_buffering off

nginx turns on proxy_buffering by default. It will try its best to read the responses data and temporarily save it, and then send it to the customer after receiving it.
After proxy_buffering is turned off, nginx will immediately send the obtained mp4 data to the client. After the client collects enough metadata for playback, it can start playing, usually very quickly (if the file itself is not suitable for streaming media playback, it is another problem. It happened, but it’s rare anymore)

SF’s first answer, please correct me if I am wrong.

Reference documentation: http://nginx.org/en/docs/http...