Customizations to the prlogging.xml file must be manually ported after upgrade
Valid from Pega Version 7.3
As a result of the upgrade from the Apache Log4j 1 logging service to the Apache Log4j 2 logging service, the name of the logging configuration file has changed from prlogging.xml to prlog4j2.xml and the format of the file has changed considerably. If you customized your prlogging.xml file, port the customizations to the new prlog4j2.xml file. If you do not port the changes, the Pega® Platform uses the default prlog4j2.xml file and disregards your customized prlogging.xml file.
For more information about customizing your log files, see the Apache Log4j 2 documentation.
Socket server has changed for remote logging
Valid from Pega Version 7.3
As a result of the upgrade from the Apache Log4j 1 logging service to the Apache Log4j 2 logging service, the socket server that is used for remote logging has changed from the Log4j remote logging package with the LogFactor5 log analysis tool to TcpSocketServer. If you use remote logging, update your socket server to TcpSocketServer. For more information, see Installing and using remote logging.
Log file description in web.xml incorrect after upgrade to Apache Log4j 2
Valid from Pega Version 7.3
As a result of the upgrade from the Apache Log4j 1 logging service to the Apache Log4j 2 logging service, it is recommended that you update the log file description in the web.xml file from location of prlogging.xml file to location of prlog4j2.xml file. The description indicates which log file is in use. Updating the description avoids confusion about which log file is current. Change the description as shown in the following example.
<resource-ref id="ResourceRef_5">
<description>location of prlog4j2.xml file</description>
<res-ref-name>url/pegarules.logging.configuration</res-ref-name>
<res-type>java.net.URL</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>