Migrating to Raft subgroups v5.6

You can introduce Raft subgroups in a running PGD installation.

Migrating to Raft subgroups (using SQL only)

To enable Raft subgroups to an existing cluster, these configuration steps are needed:

• Identify the top-level group for all nodes in the PGD cluster. An existing cluster already has a top-level group that all nodes belong to.
• Create a subgroup for each location. Use bdr.create_node_group with a parent_group_name argument that gives the top-level group as its value.
• Add each node at each location to their location’s subgroup using bdr.switch_node_group().
• Alter each of the location’s subgroups to enable Raft for the group. Use bdr.alter_node_group_option(), setting the enable_raft option to true.

Enabling subgroup Raft node group (using SQL only)

SELECT bdr.alter_node_group_option('$group_name', 'enable_raft', 'true');