How to set port on application startup correctly

[Gryslley]

Hey,

I want to use this log4j appender for Fluentd.
My problem is that I need to set the port variable depending on the user.
Therefore I use ThredContext.put("portProp", "12345") in my main.
Also, I use <Sevcer host="localhost" port="${ctx:portProp}" in the log4j2.xml, which should work.
At least it works for every pool thread, except for pool-2-thread-1, which gets the default number 0.
However, if I want to set some other variable in the xml file in the same way, it works perfectly fine.
Can you tell me what the problem is and how I can fix it?

Best regards,
David