During Logstash 5.2.1 boot which uses kafka input, just noticed a few warnings:
log4j:WARN No appenders could be found for logger (org.apache.kafka.clients.consumer.ConsumerConfig).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
I have found some similar issues:
but it's still unclear for me how to avoid them.
Should I create a logging.yml file? may I add a runtime arg? Could I add some config on logstash.yml? Or in log4j2.properties?