Introduction to Kafka Logs

This section applies to MRS 3.x or later.

Log Description

Log paths: The default storage path of Kafka logs is /var/log/Bigdata/kafka. The default storage path of audit logs is /var/log/Bigdata/audit/kafka.

Broker: /var/log/Bigdata/kafka/broker (run logs)

Log archive rule: The automatic Kafka log compression function is enabled. By default, when the size of logs exceeds 30 MB, logs are automatically compressed into a log file named in the following format: <Original log file name>-<yyyy-mm-dd_hh-mm-ss>.[ID].log.zip. A maximum of 20 latest compressed files are retained by default. You can configure the number of compressed files and the compression threshold.

**Table 1** Kafka log list
Type	Log File Name	Description
Run log	server.log	Server run log of the broker process
	controller.log	Controller run log of the broker process
	kafka-request.log	Request run log of the broker process
	log-cleaner.log	Cleaner run log of the broker process
	state-change.log	State-change run log of the broker process
	kafkaServer-<SSH_USER>-<DATE>-<PID>-gc.log	GC log of the broker process
	postinstall.log	Work log after broker installation
	prestart.log	Work log before broker startup
	checkService.log	Log that records whether broker starts successfully
	start.log	Startup log of the broker process
	stop.log	Stop log of the broker process
	checkavailable.log	Log that records the health check details of the Kafka service
	checkInstanceHealth.log	Log that records the health check details of broker instances
	kafka-authorizer.log	Broker authorization log
	kafka-root.log	Broker basic log
	cleanup.log	Cleanup log of broker uninstallation
	metadata-backup-recovery.log	Broker backup and recovery log
	ranger-kafka-plugin-enable.log	Log that records the Ranger plug-ins enabled by brokers
	server.out	Broker JVM log
	audit.log	Authentication log of the Ranger authentication plug-in. This log is archived in the /var/log/Bigdata/audit/kafka directory.

Log Level

Table 2 describes the log levels supported by Kafka.

Levels of run logs are ERROR, WARN, INFO, and DEBUG from the highest to the lowest priority. Run logs of equal or higher levels are recorded. The higher the specified log level, the fewer the logs recorded.

**Table 2** Log levels
Level	Description
ERROR	Logs of this level record error information about system running.
WARN	Logs of this level record exception information about the current event processing.
INFO	Logs of this level record normal running status information about the system and events.
DEBUG	Logs of this level record the system information and system debugging information.

To modify log levels, perform the following operations:

Go to the All Configurations page. See Modifying Cluster Service Configuration Parameters.
On the menu bar on the left, select the log menu of the target role.
Select a desired log level.
Save the configuration. In the displayed dialog box, click OK to make the configurations take effect.

Log Format

The following table describes the Kafka log format.

**Table 3** Log formats
Type	Format	Example
Run log	<yyyy-MM-dd HH:mm:ss,SSS>\|<Log Level>\|<Thread that generates the log>\|<Message in the log>\|<Full name of the log event invocation class>(<Log file>:<Row>)	2015-08-08 11:09:53,483 \| INFO \| [main] \| Loading logs. \| kafka.log.LogManager (Logging.scala:68)
Run log	<yyyy-MM-dd HH:mm:ss><HostName><Component name><logLevel><Message>	2015-08-08 11:09:51 10-165-0-83 Kafka INFO Running kafka-start.sh.