If you have an existing deployment of Group Replication and you
want to use it to create a cluster, pass the
adoptFromGR
option to the
dba.createCluster()
function. The created
InnoDB cluster matches whether the replication group is
running as single-primary or multi-primary.
To adopt an existing Group Replication group, connect to a group
member using MySQL Shell. In the following example a
single-primary group is adopted. We connect to
gr-member-2
, a secondary instance, while
gr-member-1
is functioning as the group's
primary. Create a cluster using
dba.createCluster()
, passing in the
adoptFromGR
option. For example:
mysql-js> var cluster = dba.createCluster('prodCluster', {adoptFromGR: true});
A new InnoDB cluster will be created on instance 'root@gr-member-2:3306'.
Creating InnoDB cluster 'prodCluster' on 'root@gr-member-2:3306'...
Adding Seed Instance...
Cluster successfully created. Use cluster.addInstance() to add MySQL instances.
At least 3 instances are needed for the cluster to be able to withstand up to
one server failure.
If the instance has
super_read_only=ON
then you
might need to confirm that AdminAPI can set
super_read_only=OFF
. See
Super Read-only and Instances for more
information.
The new cluster matches the mode of the group. If the adopted group was running in single-primary mode then a single-primary cluster is created. If the adopted group was running in multi-primary mode then a multi-primary cluster is created.