How to start AEM in debug mode?

There are multiple approaches to start or tune AEM instance in debug mode. we will cover a few of them in this tutorial.

1. We could start AEM using the command prompt by using the below command line.

 java -jar aem63-author-p4502.jar -debug <port#>

2. Another way to start tune AEM instance in debug mode is we could update the start.bat file and start AEM by clicking on the start.bat file in the crx-quickstart folder. To do so we have to do the following.

• First we need to update the start file; go to \crx-quickstart\bin\start.bat and append this command "-debug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=<port#>" with line 25, default JVM options.
• Save the file
•  Now double click on the start.bat file to start your AEM instance.

After changes, your start.bat file will look like the following.

@echo off

:: This script configures the start information for this server.

::

:: The following variables may be used to override the defaults.

:: For one-time overrides the variable can be set as part of the command-line; e.g.,

::

::     SET CQ_PORT=1234 & ./start.bat

::

setlocal

::* TCP port used for stop and status scripts

if not defined CQ_PORT set CQ_PORT=4502

::* hostname of the interface that this server should listen to

:: if not defined CQ_HOST set CQ_HOST=

::* runmode(s)

::* will not be used if repository is already present

if not defined CQ_RUNMODE set CQ_RUNMODE=author

::* name of the jarfile

:: if not defined CQ_JARFILE set CQ_JARFILE=

::* default JVM options

if not defined CQ_JVM_OPTS set CQ_JVM_OPTS=-Xmx2048m -XX:MaxPermSize=512M -Djava.awt.headless=true -debug -Xnoagent -Djava.compiler=NONE -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=30303

::* ------------------------------------------------------------------------------

::* authentication

::* ------------------------------------------------------------------------------

::* when using oak (crx3) authentication must be configured using the

::* Apache Felix JAAS Configuration Factory service via the Web Console

::* see http://jackrabbit.apache.org/oak/docs/security/authentication/externalloginmodule.html

::* use jaas.config (legacy: only used for crx2 persistence)

:: if not defined CQ_USE_JAAS set CQ_USE_JAAS=true

::* config for jaas (legacy: only used for crx2 persistence)

if not defined CQ_JAAS_CONFIG set CQ_JAAS_CONFIG=etc\jaas.config

::* ------------------------------------------------------------------------------

::* persistence mode

::* ------------------------------------------------------------------------------

::* the persistence mode can not be switched for an existing repository

set CQ_RUNMODE=%CQ_RUNMODE%,crx3,crx3tar

:: set CQ_RUNMODE=%CQ_RUNMODE%,crx3,crx3mongo

::* settings for mongo db

:: if not defined CQ_MONGO_HOST set CQ_MONGO_HOST=127.0.0.1

:: if not defined CQ_MONGO_PORT set CQ_MONGO_PORT=27017

:: if not defined CQ_MONGO_DB   set CQ_MONGO_DB=aem6

::* ------------------------------------------------------------------------------

::* do not configure below this point

::* ------------------------------------------------------------------------------

chdir /D %~dp0

cd ..

if exist conf\controlport del conf\controlport

if not defined CQ_JARFILE     for %%X in (app\*.jar) do set CQ_JARFILE=%%X

for %%* in (.) do set CurrDirName=%%~n*

cd ..

set START_OPTS=start -c %CurrDirName% -i launchpad

if defined CQ_PORT            set START_OPTS=%START_OPTS% -p %CQ_PORT%

if defined CQ_RUNMODE         set CQ_JVM_OPTS=%CQ_JVM_OPTS% -Dsling.run.modes=%CQ_RUNMODE%

if defined CQ_HOST            set CQ_JVM_OPTS=%CQ_JVM_OPTS% -Dorg.apache.felix.http.host=%CQ_HOST%

if defined CQ_HOST            set START_OPTS=%START_OPTS% -a %CQ_HOST%

if defined CQ_MONGO_HOST      set START_OPTS=%START_OPTS% -Doak.mongo.host=%CQ_MONGO_HOST%

if defined CQ_MONGO_PORT      set START_OPTS=%START_OPTS% -Doak.mongo.port=%CQ_MONGO_PORT%

if defined CQ_MONGO_DB        set START_OPTS=%START_OPTS% -Doak.mongo.db=%CQ_MONGO_DB%

if defined CQ_USE_JAAS        set CQ_JVM_OPTS=%CQ_JVM_OPTS% -Djava.security.auth.login.config=%CQ_JAAS_CONFIG%

set START_OPTS=%START_OPTS% -Dsling.properties=conf/sling.properties

if exist newTaskList.txt del newTaskList.txt

if exist oldTaskList.txt del oldTaskList.txt

tasklist /FI "IMAGENAME eq java.exe" /NH > oldTaskList.txt

start "CQ" cmd.exe /C java %CQ_JVM_OPTS% -jar %CurrDirName%\%CQ_JARFILE% %START_OPTS%

:: removing the delay until CQ-4202186 is solved

:: timeout /T 1 /NOBREAK >nul

tasklist /FI "IMAGENAME eq java.exe" /NH > newTaskList.txt

java -cp %~dp0 GetProcessID oldTaskList.txt newTaskList.txt java.exe > %CurrDirName%\conf\cq.pid

if exist newTaskList.txt del newTaskList.txt

if exist oldTaskList.txt del oldTaskList.txt

Once you have done with the above changes and started your AE in debug mode then you have to configure debugger in your IDE (Eclipse or IntelliJ). To configure the debugger with your local AEM instance please follow this article. Remote debugger in eclipse