How to use multiple appenders of same type with one logger using properties file?

Question

I have what should be a simple question but I can't figure it out. What is the correct syntax to use multiple appenders of the same type (RollingFile) with a single logger in Log4j2 properties file format?

For background, I am using Karaf 4.2.7 which uses pax logging. My logging config file is in the properties format.

log4j2.appender.fileapp1.type = RollingRandomAccessFile
log4j2.appender.fileapp1.name = FileApp1
...

log4j2.appender.fileapp2.type = RollingRandomAccessFile
log4j2.appender.fileapp2.name = FileApp2
...

log4j2.logger.myloggername.name = com.acme
log4j2.logger.myloggername.appenderRef.RollingFile.ref = FileApp1, FileApp2

Putting both appenders on that last line separated by a comma does not work. It works if I have only one appender or the other. I also tried

log4j2.logger.myloggername.appenderRef.RollingFile.ref = [FileApp1, FileApp2]

log4j2.logger.myloggername.appenderRef.RollingFile.ref = {FileApp1, FileApp2}

log4j2.logger.myloggername.appenderRef.RollingFile.ref = [{FileApp1}, {FileApp2}]

None of those works. I can't seem to find any examples online of how to do this.

Why not use a different format for the configuration file, for example XML? — D.B.
Simply because Karaf comes with a properties config file that already has lots of loggings stuff built in. I would rather not port that file over to XML. My changes are only a small fraction of the total properties file. — jonathan

jornathan jornathan · Accepted Answer · 2019-10-23T05:10:00

I refer to two web page(thanks).

Add and define "~s".

appenders, appenderRefs,

This is notice for define what will be on next.

name=PropertiesConfig
property.filename_fileapp1 = ./logs/fileapp1.log
property.filename_fileapp2 = ./logs/fileapp2.log

appenders = console, fileapp1, fileapp2

appender.console.type = Console
appender.console.name = STDOUT
...

appender.fileapp1.type = RollingRandomAccessFile
appender.fileapp1.name = fileapp1_AppenderName
appender.fileapp1.fileName = ${filename_fileapp1}
appender.fileapp1.filePattern = ${filename_fileapp1}.%d{yyyy-MM-dd}.log
...

appender.fileapp2.type = RollingRandomAccessFile
appender.fileapp2.name = fileapp2_AppenderName
appender.fileapp2.fileName = ${filename_fileapp2}
appender.fileapp2.filePattern = ${filename_fileapp2}.%d{yyyy-MM-dd}.log
...


loggers = mylogger1
logger.mylogger1.name = com.jornathan.sample.log4j2PropertyTest
logger.mylogger1.level = info   

#keep this value for testing.
logger.mylogger1.additivity = true

#Here is what you need.
logger.mylogger1.appenderRefs = fileapp1Appender, fileapp2Appender   
logger.mylogger1.appenderRef.fileapp1Appender.ref = fileapp1_AppenderName
logger.mylogger1.appenderRef.fileapp2Appender.ref = fileapp2_AppenderName

How to use multiple appenders of same type with one logger using properties file?

1 Answers