SingleStore DB

Setting Up Replication

This example will guide you through setting up replication of a database. These instructions assume that you have two SingleStore DB clusters running; the primary cluster contains the source data that is replicated to the secondary cluster.

Notice

To replicate a database, the secondary cluster user must have CREATE DATABASE privileges and the primary cluster user (the one specified in REPLICATE DATABASE) must have the ALL PRIVILEGES permission on the primary cluster’s master aggregator.

The following host:port combinations represent the master aggregators of the primary and secondary clusters:

  • primary-MA:3306

  • secondary-MA:3306

Note that the primary and secondary clusters need not have identical topologies. SingleStore DB will automatically manage sharding of replica data on the secondary cluster. In this example, primary-MA has a root user with an empty password.

To begin replicating the database db_name from primary-MA, run the following command on secondary-MA:

REPLICATE DATABASE db_name FROM root:'root_password'@primary-MA:3306;

You always initiate replication from the secondary cluster. You can start replication to a secondary cluster without pausing the primary cluster.

Multiple secondary clusters can replicate from a single primary cluster. To do this, run REPLICATE DATABASE on the master aggregator of each of the replica clusters.

Notice

Data is always replicated across clusters asynchronously. Databases are replicated at the leaf level, which implies that a leaf in the secondary cluster replicates data directly from a leaf in the primary cluster; therefore, when connecting a secondary cluster to the primary cluster, the leaves in the primary and secondary cluster must be able to communicate with each other. They should not be blocked by firewall or network rules.