Overview on CQ Logs

CQ provides a standard logging mechanism to log activities going on in the system.

Various CQ Logs (CQ5.6):
OOTB CQ Comes with following logs
<installation-path>\crx-quickstart\logs
<installation-path>\crx-quickstart\repository\

Log File Name: revision.log

Description
Revision information for cluster index sync
<installation-path>\crx-quickstart\repository\repository\index
Log File Name: redo.log

Description
If something goes wrong with index creation this log is created which holds redo index information.
This log is not present by default.

Create Custom Log Files:
CQ also provides a way to create custom log files to debug your application. To do that do the following.

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