- 2.4.1 Configuring Multi-Source Replication
- 2.4.2 Provisioning a Multi-Source Replication Slave for GTID-Based Replication
- 2.4.3 Adding GTID-Based Masters to a Multi-Source Replication Slave
- 2.4.4 Adding a Binary Log Based Master to a Multi-Source Replication Slave
- 2.4.5 Starting Multi-Source Replication Slaves
- 2.4.6 Stopping Multi-Source Replication Slaves
- 2.4.7 Resetting Multi-Source Replication Slaves
- 2.4.8 Multi-Source Replication Monitoring
MySQL multi-source replication enables a replication slave to receive transactions from multiple immediate masters in parallel. In a multi-source replication topology, a slave creates a replication channel for each master that it should receive transactions from. For more information on how replication channels function, see Section 5.3, “Replication Channels”.
You might choose to implement multi-source replication to achieve goals like these:
Backing up multiple servers to a single server.
Merging table shards.
Consolidating data from multiple servers to a single server.
Multi-source replication does not implement any conflict detection or resolution when applying transactions, and those tasks are left to the application if required.
Each channel on a multi-source replication slave must replicate from a different master. You cannot set up multiple replication channels from a single slave to a single master. This is because the server IDs of replication slaves must be unique in a replication topology. The master distinguishes slaves only by their server IDs, not by the names of the replication channels, so it cannot recognize different replication channels from the same slave.
A rmulti-source replication slave can also be set up as a
multi-threaded replication slave, by setting the
variable to a value greater than 0. When you do this on a
multi-source replication slave, each channel on the slave has the
specified number of applier threads, plus a coordinator thread to
manage them. You cannot configure the number of applier threads for
This section provides tutorials on how to configure masters and slaves for multi-source replication, how to start, stop and reset multi-source slaves, and how to monitor multi-source replication.