$request_time

Description

The $request_time variable provides an accurate measurement of the time taken to handle a client request in NGINX. This variable is calculated when the request is completed, capturing the duration from the moment it is received to when the response is sent back to the client. Specifically, $request_time records this time in seconds and fractions of a second, allowing you to assess performance and troubleshoot latency issues in your application. The value of $request_time is set during the processing phase of the request, immediately before NGINX sends the response. It's important to note that the time recorded can be influenced by several factors including network latency, server processing time, and client behavior (such as connection speed). As a result, typical values for $request_time vary widely depending on the application and server load; they can range from a few milliseconds to several seconds, especially under high traffic conditions or resource-intensive operations.

Config Example

log_format custom '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" request_time: $request_time';

access_log /var/log/nginx/access.log custom;