Using the Spock --Synchronize Options to Simplify Setup

The Spock sub-create (opens in a new tab) command includes two options that you can use to simplify replication configuration:

spock sub-create --synchronize_data spock sub-create --synchronize_structure

The --synchronize options pull information to a node when you define a subscription, saving you the inconvenience of manually duplicating the table structure and data. You can specify the options individually or together.

To use the --synchronize options:

1. Configure your first replication node; when setting up the node, make the node a member of the default replication set.

2. Use the spock node-create (opens in a new tab) command to define the subscribing node.

3. Use the spock sub-create (opens in a new tab) command to subscribe the new node to the node created in step 1, and include:

• spock sub-create --synchronize_data to pull data over to the new node from the existing node. Note that the table must exist on the new node in the same form as the table defined on node 1.
• spock sub-create --synchronize_structure to pull the table structure(s) over to the new node from the existing node. Note that the --synchronize_structure option can only create those objects that do not exist on the new node.
• Include both options to pull the structure definition and data to the new node.

4. After syncing the data and/or structure, use pgEdge Platform to install and create any extensions (opens in a new tab) you use on the new node:

pgedge um install extension_name

Example

In the following example, if the table and data that we want to replicate is on a node named n1:

spock node-create n1 'host=10.0.0.8 user=replication_user dbname=acctg' acctg

Where n1 is a member of the default replication set:

spock repset-add-table default 'public.customers' acctg

We can create a node named n2:

spock node-create n2 'host=10.0.0.5 user=replication_user dbname=acctg port=5432' acctg

Then, in the command to subscribe n2 to n1, include the --synchronize flags:

spock sub-create sub_n2n1 'host=10.0.0.8 port=5432 user=replication_user dbname=acctg' acctg --synchronize_structure=True --synchronize_data=True

The table structure will be recreated on n2, and populated with the data from n1.