Adding a custom field in log4j using SyslogAppender

Question

I'm using the SyslogAppender in my java application and I'm trying to add a custom field to the resulting log. How can I add an additional field to my log4j.properties?

My current log4j.properties (the last line shows what I want to achieve):

log4j.appender.SYSLOG=org.apache.log4j.net.SyslogAppender
log4j.appender.SYSLOG.threshold=INFO
log4j.appender.SYSLOG.syslogHost=localhost
log4j.appender.SYSLOG.facility=LOCAL4
log4j.appender.SYSLOG.header=true
log4j.appender.SYSLOG.layout=org.apache.log4j.PatternLayout
log4j.appender.SYSLOG.layout.conversionPattern=my-app: %m%n
log4j.appender.SYSLOG.applicationName=${STACKNAME}

The ${STACKNAME} is a system property configured by the deployment job, depending on the environment (e.g. prod, test, dev).

score 0 · Answer 1 · answered Jun 08 '17 at 11:31

From this answer I get the answer: add the lines

log4j.appender.graylog2.additionalFields={'filed_name': 'field_value', 'field2_name': 'field2_value'}
log4j.appender.graylog2.addExtendedInformation=true

to add field_name and field2_name with values field_value and field2_value. The property addExtendedInformation=true indicates Graylog to add those fields to all log entries.

Adding a custom field in log4j using SyslogAppender

1 Answers1