# Settings for the Log4j Appender instrumentation | System property | Type | Default | Description | |-----------------------------------------------------------------------------------| ------- | ------- |-----------------------------------------------------------------------------------------------------------------------| | `otel.instrumentation.log4j-appender.experimental-log-attributes` | Boolean | `false` | Enable the capture of experimental log attributes `thread.name` and `thread.id`. | | `otel.instrumentation.log4j-appender.experimental.capture-map-message-attributes` | Boolean | `false` | Enable the capture of `MapMessage` attributes. | | `otel.instrumentation.log4j-appender.experimental.capture-marker-attribute` | Boolean | `false` | Enable the capture of Log4j markers as attributes. | | `otel.instrumentation.log4j-appender.experimental.capture-mdc-attributes` | String | | Comma separated list of context data attributes to capture. Use the wildcard character `*` to capture all attributes. |