Hello,

I am looking at some NGINX logs that show that the upstream_response_time is in milliseconds(around 100-200 milliseconds) but the request_time for these requests are above 100 seconds. This happens intermittently only when the response payload is above 20 MB. Most of the times, these requests have a request_time of around 4-5 seconds for the same request payload. I see no CPU utilization or I/O spikes on these servers when the higher request_time was observed. I also have proxy_buffering on with the below configuration:

proxy_buffering on;
proxy_buffers_size 16k;
proxy_buffers 4 128k;

I tried tuning these parameters a little, but I see no significant impact on the request_time. Can anybody help me understand what am I missing? What could be done to resolve this issue?

Thanks, in advance!