How to configure asynchronous logging in Liferay

Issue

• How can I configure Log4j to use asynchronous logging in Liferay?

Environment

• DXP 7.2
• DXP 7.3
• DXP 7.4
• Quarterly Releases

Resolution

DXP 7.2 and DXP 7.3

NOTE: The following resolution requires customization and should only be implemented at the discretion of your team. Liferay Support will not be able to assist with designing or implementing customizations.

• In 7.2 and 7.3, you can configure asynchronous logging by editing the log4j configuration file.
• Create a portal-log4j-ext.xml file following the instructions at Adjusting Log Levels to persist after portal restart
• Then modify the file to define a new appender of the class org.apache.log4j.AsyncAppender, and reference that appender from the root appender:

<appender name="ASYNC" class="org.apache.log4j.AsyncAppender" />
...
<root>
...
	<appender-ref ref="ASYNC" />
...
</root>

• For a more detailed example, see the attached DXP 7.2 portal-log4j-ext.xml.

DXP 7.4 and Quarterly Releases

NOTE: Liferay Support does not recommend or endorse specific third-party products over others. The information provided about products not created by Liferay is for reference purposes only, and any implementation of these principles will be at your team's discretion.

• In 7.4 and above, we migrated to version 2.x of log4j.
• In log4j 2.x, you can deploy a third-party disruptor.jar to gain access to an AsyncLogger that you can configure to make all loggers asynchronous with a system property.
• See Log4J's 'Asynchronous Loggers for Low-Latency Logging' for detailed instructions.

Additional Information

• See Adjusting Log Levels to persist after portal restart for information on editing the log4j configuration file.
• See Log4j's documentation on the AsyncAppender for more information on how to use the appender.
• See Log4j's 'Asynchronous Loggers for Low-Latency Logging' for information on how to configure Asynchronous Loggers.