# Manage Control Center Logs for Confluent Platform Use this topic to enable and manage logs for Control Center. ## Control Center logging Control Center and other Confluent Platform components use the Java-based logging utility [Apache Log4j2](https://en.wikipedia.org/wiki/Log4j) to collect runtime data and record component events. The following table describes each log level. | Level | Description | |---------|-----------------------------------------------------------------------------------| | OFF | Turns off logging. | | FATAL | Severe errors that cause premature termination. | | ERROR | Other runtime errors or unexpected conditions. | | WARN | Runtime situations that are undesirable or unexpected, but not necessarily wrong. | | INFO | Runtime events of interest at startup and shutdown. | | DEBUG | Detailed diagnostic information about events. | | TRACE | Detailed diagnostic information about everything. | By default, Control Center writes `INFO`, `WARN`, `ERROR`, and `FATAL` information to standard output (stdout). If you want to see all events, you can set `DEBUG` or `TRACE` logging levels. You can select your desired log4j2 configuration by setting the `CONTROL_CENTER_log4j2_OPTS` environment variable when starting Control Center. Considerations: : - Control Center logging has migrated to Log4j2 library. - Log4j library is no longer supported. - The Log4j2 library uses the `.yaml` format instead of `.properties`. - You must update any custom logging configurations to use the new Log4j2 yaml format. ## log4j2 yaml files A default Control Center log4j2 template file is provided with Control Center. This yaml file is located in the directory: `etc/confluent-control-center/log4j2.yaml` The following shows an example of what the default log file contains: ```yaml Configuration: status: WARN Appenders: Console: - name: Stdout Target: SYSTEM_OUT PatternLayout: pattern: "[%d{yyyy-MM-dd HH:mm:ss,SSS}] %p [%t] %m (%c)%n" - name: Streams PatternLayout: pattern: "[%d{yyyy-MM-dd HH:mm:ss,SSS}] %p [%t] %m (%c)%n" Filters: - Log4jRateFilter: level: WARN rate: 25 Loggers: Root: level: info AppenderRef: - ref: Stdout Logger: - name: org.apache.kafka.streams level: info AppenderRef: - ref: Streams additivity: false - name: io.confluent.controlcenter.streams level: info AppenderRef: - ref: Streams additivity: false - name: kafka level: info AppenderRef: - ref: Stdout - name: org.apache.kafka level: info AppenderRef: - ref: Stdout - name: org.apache.kafka.clients.consumer level: info AppenderRef: - ref: Stdout - name: org.apache.zookeeper level: warn AppenderRef: - ref: Stdout - name: org.I0Itec.zkclient level: warn AppenderRef: - ref: Stdout ``` Confluent also provides `etc/confluent-control-center/log4j2-rolling.yaml` as an example of setting up Control Center with rolling log files that simplify log management. The rolling log file creates three, size-limited log files that isolate information: * `control-center.log` - Control Center, HTTP activity, anything not related to streams, REST API calls * `control-center-streams.log` - Streams * `control-center-kafka.log` - Client, ZooKeeper, and Kafka The following shows an example of what the rolling log file contains: ```yaml Configuration: status: WARN name: Log4j2Config Appenders: RollingFile: - name: Main fileName: ${sys:confluent.controlcenter.log.dir}/control-center.log filePattern: ${sys:confluent.controlcenter.log.dir}/control-center-%i.log PatternLayout: pattern: "[%d{yyyy-MM-dd HH:mm:ss,SSS}] %p [%t] %m (%c)%n" Policies: SizeBasedTriggeringPolicy: size: 10MB DefaultRolloverStrategy: max: 5 - name: Streams fileName: ${sys:confluent.controlcenter.log.dir}/control-center-streams.log filePattern: ${sys:confluent.controlcenter.log.dir}/control-center-streams-%i.log PatternLayout: pattern: "[%d{yyyy-MM-dd HH:mm:ss,SSS}] %p [%t] %m (%c)%n" Policies: SizeBasedTriggeringPolicy: size: 10MB DefaultRolloverStrategy: max: 5 Filters: - Log4jRateFilter: level: WARN rate: 25 - name: Kafka fileName: ${sys:confluent.controlcenter.log.dir}/control-center-kafka.log filePattern: ${sys:confluent.controlcenter.log.dir}/control-center-kafka-%i.log PatternLayout: pattern: "[%d{yyyy-MM-dd HH:mm:ss,SSS}] %p [%t] %m (%c)%n" Policies: SizeBasedTriggeringPolicy: size: 10MB DefaultRolloverStrategy: max: 5 Loggers: Root: level: info AppenderRef: - ref: Main Logger: - name: org.apache.kafka.streams level: info AppenderRef: - ref: Streams additivity: false - name: io.confluent.controlcenter.streams level: info AppenderRef: - ref: Streams additivity: false - name: kafka level: info AppenderRef: - ref: Kafka additivity: false - name: org.apache.kafka level: info AppenderRef: - ref: Kafka additivity: false - name: org.apache.zookeeper level: warn AppenderRef: - ref: Kafka additivity: false - name: org.I0Itec.zkclient level: warn AppenderRef: - ref: Kafka additivity: false ``` You can add additional entries and change log levels by updating these configuration files. ## Enable logs for Control Center You set your logging configuration with a Control Center environment variable at start up. To set the logging configuration for Control Center: * Set and export the `CONTROL_CENTER_log4j2_OPTS` environment variable similar to this example: ```bash export CONTROL_CENTER_log4j2_OPTS='-Dlog4j2.configuration=file:/etc/confluent-control-center/' ``` You must restart Control Center to apply changes to logging with an environment variable. For more information, see [Restarting Control Center](properties.md#c3-restart). ## Change log levels for Control Center You can change log levels to help debug issues. The following commands show how to set root logging levels to **DEBUG** or **TRACE**. - To enable debug logging, change the log level to `DEBUG` at the root level: ```yaml Loggers: Root: level: debug AppenderRef: - ref: Stdout ``` - To enable trace logging, change the root logger to `TRACE` at the root level: ```yaml Loggers: Root: level: trace AppenderRef: - ref: Stdout ``` When you are done debugging and tracing, reset the log levels back to their defaults and restart Control Center. For more information, see [Restarting Control Center](properties.md#c3-restart). ## Set custom log directory location The location the logs are written depends on the type of installation. - RPM/Debian installation: `/var/log/kafka` - ZIP/TAR installation: `$base_dir/logs` You set a custom logging location with an environment variable at start up. To set a custom location, use the following environment variable: - `LOG_DIR` To set the custom location for logs: * Set and export the `LOG_DIR` environment variable similar to this example: ```bash export LOG_DIR='/my/logs/' ``` You must restart Control Center to apply changes to logging with an environment variable. For more information, see [Restarting Control Center](properties.md#c3-restart). If you are using Ansible Playbooks for Confluent Platform, use the variable `control_center_log_dir` to write Control Center logs to a custom directory. For more information, see [Ansible Playbooks for Confluent Platform](https://docs.confluent.io/ansible/current/overview.html). ## Related content - [Log redaction](/platform/current/security/protect-data/log-redaction.html#log-redaction)