How to start the first node in a Galera Cluster?
To start the first node–which should have MySQL, MariaDB or Percona XtraDB Cluster, and Galera installed–you’ll have to launch the database server on it with the –wsrep-new-cluster option. There are different ways to do this, depending on the operating system. For systems that use init, execute the following from the command-line:
When to migrate from MySQL to Galera Cluster?
When migrating from an existing, stand-alone instance of MySQL, MariaDB or Percona XtraDB Cluster to Galera Cluster, there will be some additional steps that you must take. For more information on what you need to do, see Migration.
How do I start mysqld on one node?
To do this, you will need to start the mysqld daemon on one node, using the –wsrep-new-cluster option. This initializes the new Primary Component for the cluster.
How does state exchange work in Galera Cluster?
When the nodes in the cluster agree on the membership state, they initiate state exchange. In state exchange, a new node will check the cluster state. If the state of a new node differs from the cluster state–which is normally the case–the new node requests a state snapshot transfer (SST) from the cluster and it installs it on its local database.
What kind of replication does Galera Cluster use?
Galera Cluster uses a multi-master method of replication. It allows you to write to any node in a cluster; writes on any node are synchronized to all nodes. Standard MySQL replication uses one master and multiple slaves: although you can read data from any node, you can write only on the master.
How is safe to bootstrap set in Galera Cluster?
The variable safe_to_bootstrap is set to 0 on the first node after it’s been bootstrapped to protect against you inadvertently bootstrapping again while the cluster is runnning. You’ll have to change the value to 1 to be able to bootstrap anew.