By default, Acquia retains Apache, Drupal, PHP and MySQL logs that contain information on site and user behaviour for your application. As information for a single request is spread across these logs, narrowing down information can, at times, be challenging.
Acquia Cloud assigns each request a unique request_id in the HTTP header X-Request-ID, and preserves that request_id across multiple log files.
Once you have identified a request_id in the drupal-request log file, you can use grep and/or zgrep in the command line to check to which entry in the access.log file this request is associated to.
For example:
grep "unique request id" example.log
zgrep "unique request id" example.gz
Please note that you can access all your log files by connecting to your web servers, as explained in https://docs.acquia.com/acquia-cloud/monitor/logs/