- 2.5.1 Configuring Multi-Source Replication
- 2.5.2 Provisioning a Multi-Source Replica for GTID-Based Replication
- 2.5.3 Adding GTID-Based Sources to a Multi-Source Replica
- 2.5.4 Adding a Binary Log Based Source to a Multi-Source Replica
- 2.5.5 Starting Multi-Source Replicas
- 2.5.6 Stopping Multi-Source Replicas
- 2.5.7 Resetting Multi-Source Replicas
- 2.5.8 Multi-Source Replication Monitoring
MySQL multi-source replication enables a replica to receive transactions from multiple immediate sources in parallel. In a multi-source replication topology, a replica creates a replication channel for each source that it should receive transactions from. For more information on how replication channels function, see Section 5.2, “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 replica must replicate from a different source. You cannot set up multiple replication channels from a single replica to a single source. This is because the server IDs of replicas must be unique in a replication topology. The source distinguishes replicas only by their server IDs, not by the names of the replication channels, so it cannot recognize different replication channels from the same replica.
A multi-source replica can also be set up as a multi-threaded
replica, by setting the
variable to a value greater than 0. When you do this on a
multi-source replica, each channel on the replica has the specified
number of applier threads, plus a coordinator thread to manage them.
You cannot configure the number of applier threads for individual
This section provides tutorials on how to configure sources and replicas for multi-source replication, how to start, stop and reset multi-source replicas, and how to monitor multi-source replication.