In this section, we list the basic steps required to add new data nodes to a MySQL Cluster. For a detailed example, see Section 7.13.3, “Adding MySQL Cluster Data Nodes Online: Detailed Example”.
Beginning with MySQL Cluster NDB 7.0.4, this procedure applies whether you are using ndbd or ndbmtd binaries for the data node processes. Previously, this did not work with multi-threaded data nodes. (Bug #43108)
Assuming that you already have a running MySQL Cluster, adding data nodes online requires the following steps:
Edit the cluster configuration
config.ini file, adding new
[ndbd] sections corresponding to the
nodes to be added. In the case where the cluster uses
multiple management servers, these changes need to be made
config.ini files used by the
You must be careful that node IDs for any new data nodes
added in the
config.ini file do not
overlap node IDs used by existing nodes. In the event that
you have API nodes using dynamically allocated node IDs and
these IDs match node IDs that you want to use for new data
nodes, it is possible to force any such API nodes to
“migrate”, as described later in this
Perform a rolling restart of all MySQL Cluster management servers.
Perform a rolling restart of all existing MySQL Cluster data
nodes. It is not necessary (or usually even desirable) to
--initial when restarting
the existing data nodes.
If you are using API nodes with dynamically allocated IDs matching any node IDs that you wish to assign to new data nodes, you must restart all API nodes (including SQL nodes) before restarting any of the data nodes processes in this step. This causes any API nodes with node IDs that were previously not explicitly assigned to relinquish those node IDs and acquire new ones.
Perform a rolling restart of any SQL or API nodes connected to the MySQL Cluster.
Start the new data nodes.
The new data nodes may be started in any order. They can also be started concurrently, as long as they are started after the rolling restarts of all existing data nodes have been completed, and before proceeding to the next step.
Execute one or more
commands in the MySQL Cluster management client to create
the new node group or node groups to which the new data
nodes will belong.
This needs to be done only for tables already existing at
the time the new node group is added. Data in tables
created after the new node group is added is distributed
automatically; however, data added to any given table
tbl that existed before the new nodes
were added is not distributed using the new nodes until
that table has been reorganized using
TABLE tbl REORGANIZE PARTITION.
You can add all the nodes desired, then issue several
CREATE NODEGROUP commands in succession to
add the new node groups to the cluster. Prior to MySQL Cluster
NDB 7.0.16 and MySQL Cluster NDB 7.1.5, when adding multiple new
node groups to a MySQL Cluster, it was necessary to add only the
nodes to be assigned to a given new node group, create that node
CREATE NODEGROUP, then repeat
this process for each new node group to be added to the cluster.