I am having some issues with a custom appender when I enable logging for Apache
Ignite. I have a cl and pretty much follows the code laid out here:
http://logging.apache.org/log4j/2.x/manual/extending.html#Appenders. The class
also overrides append. Without enabling Ignite logging, things seem to work
fine. However, after I enable Ignite logging, I will see the following
repeatedly:
2020-02-12 12:52:37,946 INFO STDERR [Thread-2] {} 2020-02-12 12:52:37,943
Log4j2-TF-2-AsyncLoggerConfig-2 ERROR Attempted to append to non-started
appender ActLogAppender.
From that same log file and additional log statements added in ActLogAppender,
I see:
2020-02-12 12:52:32,106 INFO ActLogAppender [main] {} CreateAppender called:
ActLogAppender, wing1112, %date{DEFAULT} %-5level %logger{2}.%method.%line
[%thread] %mdc %msg%n, null
2020-02-12 12:52:32,144 INFO ActLogAppender [main] {} ActLogAppender start
called
2020-02-12 12:52:32,144 INFO ActLogAppender [main] {} ActLogAppender start
done being called with state: true
So the Appender should be started before these error messages are seen. This
could be an error within the Ignite code, but I want to understand the error
before digging deeper into that code. A couple of questions:
-What could cause this error occur, given that createAppender and start are
called before the append error occurs? The implementation of ActLogAppender
relies on the singleton pattern, so createAppender should always return the
same instance. I also only see createAppender being called once.
-The errors posted above are usually prepended to the log file, overwriting the
log statements that were there previously. We have even seen the case were a
new log file is created that contains only those error messages. We no longer
get any new logs at this point even though our process is still running. Why
does this happen? It kind of seems like there are two different loggers writing
to the same file, but not sure.
