Kafka stores log4j logs in directory literally called ${kafka.logs.dir}

Cabbage Parachute

4/23/23, 2:04 PM

I installed a preview version of Kafka 3.0 with log4j2 support (http://home.apache.org/~dongjin/post/apache-kafka-log4j2-support/) on a RHEL 8 server. Kafka and Zookeeper are running successfully as systemd user services. I set the environment variable KAFKA_LOG4J_OPTS="-Dlog4j.configurationFile=file:/home/username/kafka/bin/../config/log4j2.properties" in the systemd unit file so that log4j 2.17 ist used.

However, there is one strange thing: all log4j logs are stored in a directory literally called ${kafka.logs.dir} in the home directory. The garbage collector successfully stores logs in the correct log location ~/kafka/logs. So the directory ~/kafka/logs contains files like kafkaServer-gc.log.0.current, while the hilariously strange directory ~/${kafka.logs.dir} contains server.log, controller.log, etc.

When looking at the processes for kafka and zookeeper, I can see that they both have the argument -Dkafka.logs.dir=/home/username/kafka/bin/../logs. Shouldn't this define the environment variable kafka.logs.dir, which is used in the file config/log4j2.properties? How come that Zookeeper and Kafka apparently don't have access to this $kafka.logs.dir environment variable?

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AlexD

4/23/23, 2:24 PM

Result of disabled pattern substitution due to Log4shell fixes?

Cabbage Parachute

4/29/23, 7:44 AM

You're probably right. I added a definition of kafka.logs.dir to the beginning of log4j2.properties with the directory path and it still used `${kafka.logs.dir}` as directory name.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Kafka stores log4j logs in directory literally called ${kafka.logs.dir}

TH: Kafka เก็บบันทึก log4j ไว้ในไดเร็กทอรีที่เรียกว่า ${kafka.logs.dir}

RO: Kafka stochează jurnalele log4j în directorul numit literal ${kafka.logs.dir}

RU: Kafka хранит журналы log4j в каталоге, который буквально называется ${kafka.logs.dir}.

VI: Kafka lưu trữ nhật ký log4j trong thư mục được gọi theo nghĩa đen là ${kafka.logs.dir}

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