This section describes how naming conventions are impacted by replication channels.
Each replication channel has a unique name which is a string with a maximum length of 64 characters and is case-insensitive. Because channel names are used in replication metadata repositories, the character set used for these is always UTF-8. Although you are generally free to use any name for channels, the following names are reserved:
- group_replication_applier
- group_replication_recovery
      The name you choose for a replication channel also influences the
      file names used by a multi-source replica. The relay log files and
      index files for each channel are named
      relay_log_basename-channel.xxxxxxrelay_log_basename is a base name
      specified using the relay_log
      system variable, and channel is the
      name of the channel logged to this file. If you do not specify the
      relay_log system variable, a
      default file name is used that also includes the name of the
      channel.