4.4.7 The start cluster Command

start cluster [--initial|-i] cluster_name

This command starts the cluster named cluster_name, as shown in this example:

mcm> start cluster mycluster;
+------------------------------+
| Command result               |
+------------------------------+
| Cluster started successfully |
+------------------------------+
1 row in set (45.37 sec)

In order for the command to succeed, the cluster named in the command must already exist; otherwise the command fails with the error Cluster cluster_name not defined, as shown here:

mcm> list sites;
+--------+------+-------+------------------------------+
| Site   | Port | Local | Hosts                        |
+--------+------+-------+------------------------------+
| mysite | 1862 | Local | tonfisk,flundra,grindval,haj |
+--------+------+-------+------------------------------+
1 row in set (1.72 sec)

mcm> list clusters mysite;
+-----------+-----------+
| Cluster   | Package   |
+-----------+-----------+
| mycluster | mypackage |
+-----------+-----------+
1 row in set (1.70 sec)

mcm> start cluster yourcluster;
ERROR 5001 (00MGR): Cluster yourcluster not defined

In addition, the cluster must not already be running, as shown here:

mcm> show status --cluster mycluster;
+-----------+-------------------+---------+
| Cluster   | Status            | Comment |
+-----------+-------------------+---------+
| mycluster | fully operational |         |
+-----------+-------------------+---------+
1 row in set (0.01 sec)

mcm> start cluster mycluster;
ERROR 5005 (00MGR): Cluster mycluster is running

A cluster created for import cannot be started until the import has been completed. See Section 4.4.1, “The create cluster Command”, and Section 3.5, “Importing MySQL Clusters into MySQL Cluster Manager”, for more information.

The --initial option (short form: -i) causes all cluster data node processes to be started as if start process --initial had been used, which means that all data nodes wipe their data and start with clean data node file systems. NDB tables that were previously stored in the cluster are lost.

Under normal circumstances, you should use this option to start a cluster only when either you do not wish to preserve any of its data (and want to make a clean start), or you intend to restore the cluster from backup to a known good state (see Section 4.7.4, “The restore cluster Command”). You should also be aware that no special warnings are printed by the mcm client when --initial is used with start cluster; the command is immediately executed.

For information about creating cluster backups, see Section 4.7.2, “The backup cluster Command”. If you need to know which backups are available (if any), use list backups.

Using the --initial option with start cluster does not cause mysql_install_db to be executed, or the mysql system database to be altered or removed, on any SQL nodes. This option also does not remove MySQL Cluster Disk Data tablespace files; if their removal is needed, it must be performed manually.