What?

This is a custom appender for log4j2. When used with Java/Mule apps, This appender pushes all the application logs to specified CloudWatch. This code is a fix and upgrade of the code found here : https://www.javacodegeeks.com/2017/10/integrate-cloudwatch-logs-cloudhub-mule.html However, there was a small problem when moving the LogEvents from one que to CloudWatch. This is solved by making the LogEvent immutable:

loggingEventsQueue.offer(event.toImmutable());

Why?

• When using MuleSoft CloudHub, you may want to store the logs somewhere other than in CloudHub.
• Send all log events to a specified CloudWatch instance
• To make a backup copy for application logs.

How?

• Build this application using the following command.

mvn clean install

Use this dependency in your Java/Mule Applications

<dependency>
	<groupId>com.java.javacodegeeks.log4j2.cloudwatch</groupId>
	<artifactId>log4j2-cloudwatch-appender</artifactId>
	<version>1.0.0</version>
	<type>jar</type>
</dependency>

• Modify Application's log4j2.xml to add the below appender custom appender config.

<Appenders>
	<CLOUDW name="CloudW" logGroupName="<your CloudWatch group name>"
		logStreamName="<your Mule app name>-${sys:environment}"
		awsAccessKey="<your AWS access key>" 
        awsSecretKey="<your AWS secret key>"
		awsRegion="<your AWS region>" 
		messagesBatchSize="5"
		queueLength="100">
		<PatternLayout
			pattern="%-5p %d [%t] %X{correlationId}%c: %m%n" /> 
	</CLOUDW>
</Appenders>

Add this java package in your top level log4j2 configuration element

<Configuration packages="com.java.javacodegeeks.log4j2.cloudwatch">

Add this custom appender to your Root logger in log4j2.xml.

<Root level="INFO">
    <AppenderRef ref="CloudW"/>
</Root>  
     
        (or)

<AsyncRoot level="INFO">
    <AppenderRef ref="CloudW" />
</AsyncRoot>

• That's it!

When you run the project with this appender added with your AWS credentials, you should see your app log events flowing into the configured CloudWatch group/logStreamName.