Log4j2 KeyValuePair for .properties file

Question

How to create a keyvalue pair in log4j2 in a propterties file?

I know that in log4j version 1 this is done as:

log4j.appender.x.additionalFields={'key': 'value'}

and the XML method for it in log4j2:

  <KeyValuePair key="key" value="value"/>

so this is the way to do it for the properties file as follows:

`appender.x.keyValuePair ={'key': 'value'}`

?

Answer 1

This is a working example of how to define a pair of key values, for example, for a Graylog2 (GELF) application:

appender.graylog.type=GELF
appender.graylog.name=GRAYLOG
appender.graylog.server=yourhostname
appender.graylog.includeStackTrace=true
appender.graylog.additionalFields.type=KeyValuePair
appender.graylog.additionalFields.key=yarncontainer
appender.graylog.additionalFields.value=containerXYZ