The parsing of the log4j2 configuration file

[li_jessen2016 (Li Jessen)]

I am not familiar with xml. When I read the document about the log configuration, it writes that "appender.rolling.layout.pattern = [%d{ISO8601}][%-5p][%-25c{1.}] [%node_name]%marker %.-10000m%n "

What's the meaning of {ISO8601}, [%-5p], [%-25c{1.}], [%node_name], %marker , %.-10000m ?

[nik9000 (Nik Everett)]

This is a fairly standard log4j properties file. In general I suggest leaving it alone unless you need to do something funny with logging. If you do, I'd start a new thread asking about that.

%d{iso8601} says print the date and time in a standard format.

%-5p says print the pevel, padded to five characters and left aligned.

%-25c{1.} says to print the name of the logger, truncating in it a very particular way if it is wider than 25 characters.

%node_name is an elasticsearch extension that logs the name of the node.

%marker is replaced by the index and shard info.

The last one is the actual log message.