This section describes startup options which are impacted by the addition of replication channels.
variables must not be set to
FILE when you use replication channels. In
MySQL 8.0, the
FILE setting is deprecated, and
TABLE is the default, so the system variables
can be omitted. From MySQL 8.0.23, they must be omitted because
their use is deprecated from that release. If these system
variables are set to
FILE, attempting to add
more sources to a replica fails with
The following startup options now affect all channels in a replication topology.
All transactions received by the replica (even from multiple sources) are written in the binary log.
When set, each channel purges its own relay log automatically.
The specified number of transaction retries can take place on all applier threads of all channels.
No replication threads start on any channels.
Execution continues and errors are skipped for all channels.
The values set for the following startup options apply on each channel; since these are mysqld startup options, they are applied on every channel.
Maximum size of the individual relay log file for each channel; after reaching this limit, the file is rotated.
Upper limit for the total size of all relay logs combined, for each individual channel. For
Nchannels, the combined size of these logs is limited to
Number of replication applier threads per channel.
Waiting time by an I/O thread for each source.
Base name for each channel's relay log index file. See Section 5.2.4, “Replication Channel Naming Conventions”.
Denotes the base name of each channel's relay log file. See Section 5.2.4, “Replication Channel Naming Conventions”.
This value is set per channel, so that each channel waits for
Nseconds to check for a broken connection.
This value is set per channel, so that each channel skips
Nevents from its source.