opensearch-docs-cn/_data-prepper/logs.md

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Log4j configuration

This section provides information about configuring Log4j.

Logging

The following describes how Data Prepper performs logging. Data Prepper uses SLF4J with a Log4j 2 binding.

For Data Prepper versions 2.0 and later, the Log4j 2 configuration file can be found and edited in config/log4j2.properties in the application's home directory. The default properties for Log4j 2 can be found in log4j2-rolling.properties in the shared-config directory.

For Data Prepper versions before 2.0, the Log4j 2 configuration file can be overridden by setting the log4j.configurationFile system property when running Data Prepper. The default properties for Log4j 2 can be found in log4j2.properties in the shared-config directory.

Example

When running Data Prepper, the following command can be overridden by setting the system property -Dlog4j.configurationFile={property_value}, where {property_value} is a path to the Log4j 2 configuration file:

java "-Dlog4j.configurationFile=config/custom-log4j2.properties" -jar data-prepper-core-$VERSION.jar pipelines.yaml data-prepper-config.yaml

See the Log4j 2 configuration documentation for more information about Log4j 2 configuration.