[float] [[breaking_70_logging_changes]] === Logging changes [float] ==== New JSON format log files in `log` directory Elasticsearch now will produce additional log files in JSON format. They will be stored in `*.json` suffix files. Following files should be expected now in log directory: * ${cluster_name}_server.json * ${cluster_name}_deprecation.json * ${cluster_name}_index_search_slowlog.json * ${cluster_name}_index_indexing_slowlog.json * ${cluster_name}.log * ${cluster_name}_deprecation.log * ${cluster_name}_index_search_slowlog.log * ${cluster_name}_index_indexing_slowlog.log * ${cluster_name}_audit.json * gc.log Note: You can configure which of these files are written by editing `log4j2.properties`. [float] ==== Log files ending with `*.log` deprecated Log files with the `.log` file extension using the old pattern layout format are now considered deprecated and the newly added JSON log file format with the `.json` file extension should be used instead. Note: GC logs which are written to the file `gc.log` will not be changed. [float] ==== Docker output in JSON format All Docker console logs are now in JSON format. You can distinguish logs streams with the `type` field.