CQ_JVM_OPTS Example AEM

[nsvsrk]

Hi all,

I need to start AEM Author with some JVM parameters using CQ_JVM_OPTS.

Could this be done using Quickstart Jar invocation using Java on command line?

Please share an example.

Appreciate all your replies.

Thanks,

Rama.

[SantoshSai]

Hi @nsvsrk,

Here's how you can do it step by step:

Step 1: Prepare Your AEM Quickstart JAR

Make sure your AEM Quickstart JAR file (e.g., aem-author-p4502.jar) is in a clean directory. This JAR file will unpack and create the crx-quickstart folder when first run.

Step 2: Set Your Desired JVM Parameters

You can set JVM parameters like heap size, garbage collector type, or system properties like run modes. These are passed using the CQ_JVM_OPTS environment variable.

Example:

CQ_JVM_OPTS="-Xmx4096m -XX:+UseG1GC -Dsling.run.modes=author"

Step 3: Start the AEM Instance

Use the following command to start AEM, passing in the JVM parameters via CQ_JVM_OPTS:

java $CQ_JVM_OPTS -jar aem-author-p4502.jar

Alternatively, if you want to make things cleaner (especially in scripts), you can export the variable like this:

export CQ_JVM_OPTS="-Xmx4096m -XX:+UseG1GC -Dsling.run.modes=author"
java $CQ_JVM_OPTS -jar aem-author-p4502.jar

Commonly Used JVM Options

Here are a few useful ones you might consider:

• -Xmx4096m – Set the maximum heap size (4GB in this case)

• -Xms2048m – Set the initial heap size

• -XX:+UseG1GC – Use the G1 garbage collector

• -Dsling.run.modes=author – Run the instance in Author mode

• -Dorg.osgi.framework.bootdelegation=sun.*,com.sun.* – Sometimes used for classloading tweaks

Example Full Command

export CQ_JVM_OPTS="-Xms2048m -Xmx4096m -XX:+UseG1GC -Dsling.run.modes=author"
java $CQ_JVM_OPTS -jar aem-author-p4502.jar

That’s it! Your AEM Author instance should now start with the custom JVM parameters you’ve defined.

[nsvsrk]

Thanks Santosh.

Is the "Step 2: Set Your Desired JVM Parameters" executed in command line?
Let us say c:\author has aem-author-p4502.jar.

I could execute CQ_JVM_OPTS="-Xmx4096m -XX:+UseG1GC -Dsling.run.modes=author" on command line like below?

c:\author>CQ_JVM_OPTS="-Xmx4096m -XX:+UseG1GC -Dsling.run.modes=author"

Of course I will execute "Step 3: Start the AEM Instance" on command line only like below:

c:\author>java $CQ_JVM_OPTS -jar aem-author-p4502.jar

Thanks,

RK.

[SantoshSai · Accepted solution]

@nsvsrk 

Let’s say your AEM Quickstart JAR is at C:\author\aem-author-p4502.jar.

Here’s how to do it correctly in Windows:

Step 1: Navigate to the AEM directory

cd C:\author

Step 2: Set the JVM parameters (Windows-style)

set CQ_JVM_OPTS=-Xmx4096m -XX:+UseG1GC -Dsling.run.modes=author

This sets the CQ_JVM_OPTS variable only for the current Command Prompt session.

Step 3: Start the AEM Author instance

java %CQ_JVM_OPTS% -jar aem-author-p4502.jar