anchor.diff:  
   * Elasticsearch
   * Logstash
  -* Redis
  +* Redis (DEPRECATED)
   * File
   
   One or multiple outputs can be enabled at a time. The output plugins are
  
positive.code: 
  ===== files.rotateeverybytes
  
  Maximum Log file size. If limit is reached a new log file will be generated.
  Default log file size limit is 10485760 (=10MB).
  
  ===== files.keepfiles
  
  Number of most recent rotated log files to keep on disc. Older files will be
  deleted during log rotation. Default value is 7. The keepfiles options has to be
  in the range of 2 to 1024 files.
  
  
negative.code: In addition to the logging system, the logging output configuration can be
  modified from <<command-line-options, command line>>.
  
  ==== Logging options
  
  ===== to_syslog
  
  Send all logging output to syslog if enabled. For non Windows systems default
  value is true.
  
  ===== to_files
  
  Write all logging output to files subject to file rotation. On Windows systems
  default value is true.
  
  ===== selectors
  
  List of debugging only selector tags used by different beats components. Use `*`
  to enable debug output for all components. For example add 'publish' to display
  all the debug messages related to event publishing.
  
  ===== files.path
  
  The path setting sets the directory where the log files are written to. For Windows
  systems the default path is C:\\ProgramData\<beat-name>\Logs. Default for
  non-Windows systems is /var/log/<beat-name>.
  
  