# Logging in ksqlDB for Confluent Platform

#### IMPORTANT
Confluent Platform and its components, version 7.9 and earlier, use Log4j 1.x
and not Log4j 2.x. This affects how you configure logging and the
format of the logging configuration file. For information about
logging in Confluent Platform 7.9 and earlier, see
[Configure Confluent Platform Logging (7.8)](https://docs.confluent.io/platform/7.8/monitor/cp-logging.html).

Configure a Kafka appender in the ksqlDB Server configuration file to get
`DEBUG` or `INFO` output from ksqlDB Server. Assign the following
configuration settings in the configuration file.

```properties
log4j.appender.kafka_appender=org.apache.kafka.log4jappender.KafkaLog4jAppender
log4j.appender.kafka_appender.layout=io.confluent.common.logging.log4j.StructuredJsonLayout
log4j.appender.kafka_appender.BrokerList=localhost:9092
log4j.appender.kafka_appender.Topic=KSQL_LOG
log4j.logger.io.confluent.ksql=INFO,kafka_appender
```