Overview:

CQ provide standard logging mechanism to log activities going on in system.

Various CQ Logs (CQ5.6):

OOTB CQ Comes with following logs

<installation-path>\crx-quickstart\logs

<installation-path>\crx-quickstart\repository\

<installation-path>\crx-quickstart\repository\repository\index

Create Custom Log Files:

CQ Also provide a way to create custom log files to debug your application. To do that do following

For example if I have to set debug for package com.day.cq.dam.core

• Log into Felix Console: http://<host>:<port>/system/console/configMgr
• From "Factory Configurations", create "Apache Sling Logging Writer Configuration"
• Set value of "Log File" to "../logs/dam.log"
• Click on "Save"
• From "Factory Configurations", create "Apache Sling Logging Logger Configuration"
• Set value of "Log Level" to "Debug"
• Set value of "Log File" to "../logs/dam.log"
• Add "Logger" => com.day.cq.dam.core
• Click on "Save"

Detail information about creating custom log can be found Here

Information about how to rotate various logs in CQ can be found Here