1. Configure logging subsystem to use syslog-handler           <syslog-handler name= "SYSLOG" >                 <server-address value= "localhost" />                 <port value= "514" />                 <app-name value= "myApp" />                 <formatter>                     <named-formatter name= "PATTERN" />                 </formatter>             </syslog-handler> 2. Start the server (standalone mode) 3.You get a validation error as follows ERROR [org.jboss.as.controller] (Controller Boot Thread )  OPVDX001: Validation error in standalone-full.xml ------------------------------ | |  139:     <port value= "514" /> |  140:     <app-name value= "myapp" /> |  141:     <formatter> |           ^^^^ 'formatter' is missing one or more required child elements |                 |                All of the following are required: syslog_formatter  | |  142:         <named-formatter name= "PATTERN" /> |  143:     </formatter> |  144: </syslog-handler> | | The primary underlying error message was: | > ParseError at [row,col]:[143,17] | > Message: WFLYCTL0134: Missing required element(s): SYSLOG_FORMATTER | |------------------------------------------------------------------------------- ERROR [org.jboss.as.server] (Controller Boot Thread ) WFLYSRV0055: Caught exception during boot: org.jboss.as.controller.persistence.ConfigurationPersistenceException: WFLYCTL0085: Failed to parse configuration     at org.jboss.as.controller@15.0.1.Final //org.jboss.as.controller.persistence.XmlConfigurationPersister.load(XmlConfigurationPersister.java:143)     at org.jboss.as.server@15.0.1.Final //org.jboss.as.server.ServerService.boot(ServerService.java:403)     at org.jboss.as.controller@15.0.1.Final //org.jboss.as.controller.AbstractControllerService$1.run(AbstractControllerService.java:416)     at java.base/java.lang. Thread .run( Thread .java:834) FATAL [org.jboss.as.server] (Controller Boot Thread ) WFLYSRV0056: Server boot has failed in an unrecoverable manner; exiting. See previous messages for details. 4. Stop server and change the syslog-handler config as follows             <syslog-handler name= "SYSLOG" >               <server-address value= "localhost" />                 <port value= "514" />                 <app-name value= "myApp" />                 <formatter>                     <syslog-format syslog-type= "RFC5424" />                     <named-formatter name= "PATTERN" />                 </formatter>           </syslog-handler> 5. Restart the server and verify that validation error goes away