Comprehensive Explanation

Adobe Experience Manager maintains an HTTP request log that records incoming requests and their corresponding responses, including response times.

The request.log file is particularly useful for identifying slow page requests, diagnosing performance problems, and evaluating application responsiveness.

Each request receives an identifier that associates the incoming HTTP request with its corresponding response. The response record includes the HTTP status code, content type, and processing time.

For example:

09:43:41 [66] - > GET /content/site/en.html HTTP/1.1

09:43:41 [66] < - 200 text/html 797ms

In this example, AEM required 797 milliseconds to process the request.

Option A is incorrect because audit.log primarily records auditing information, such as content-related administrative and moderation activities.

Option B is incorrect because stdout.log captures standard-output messages, including startup-related information, rather than providing the dedicated request timing records.

Option C is correct because request.log provides a direct mechanism for analyzing HTTP response times.

Adobe recommends using request-log analysis to identify slow pages, evaluate request concurrency, and diagnose application performance bottlenecks.

For extensive performance investigations, developers can aggregate response times by URL and correlate slow requests with thread dumps, repository query performance, and application logs.

Official Adobe Reference: Monitoring and Maintaining Your AEM Instance — Interpreting the request.log; Examples of request.log Analysis.