MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0

19.2.2.4 Replication Channel Naming Conventions

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 the replica's applier metadata repository table, 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:

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.xxxxxx, where relay_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.