relay_log_info_repository.

This must be set to TABLE. If this variable is set to FILE, attempting to add more sources to a replica fails with ER_SLAVE_NEW_CHANNEL_WRONG_REPOSITORY.

master_info_repository

This must be set to TABLE. If this variable is set to FILE, attempting to add more sources to a replica fails with ER_SLAVE_NEW_CHANNEL_WRONG_REPOSITORY.

--log-slave-updates

All transactions received by the replica (even from multiple sources) are written in the binary log.

--relay-log-purge

When set, each channel purges its own relay log automatically.

--slave_transaction_retries

Applier threads of all channels retry transactions.

--skip-slave-start

No replication threads start on any channels.

--slave-skip-errors

Execution continues and errors are skipped for all channels.

--max-relay-log-size=size

Maximum size of the individual relay log file for each channel; after reaching this limit, the file is rotated.

--relay-log-space-limit=size

Upper limit for the total size of all relay logs combined, for each individual channel. For N channels, the combined size of these logs is limited to relay_log_space_limit * N.

--slave-parallel-workers=value

Number of worker threads per channel.

slave_checkpoint_group

Waiting time by an I/O thread for each source.

--relay-log-index=filename

Base name for each channel's relay log index file. See Section 16.2.2.4, “Replication Channel Naming Conventions”.

--relay-log=filename

Denotes the base name of each channel's relay log file. See Section 16.2.2.4, “Replication Channel Naming Conventions”.

--slave_net-timeout=N

This value is set per channel, so that each channel waits for N seconds to check for a broken connection.

--slave-skip-counter=N

This value is set per channel, so that each channel skips N events from its source.