Read replicas can be useful for read scaling and offloading certain workloads that could impact production (such as reporting workloads). Your read replica in Crunchy Bridge is required to be the same storage size, but can be a different instance size. You can also provision read replicas across regions and infrastructure provider if you wish to have greater resilience should a specific cloud provider or region fail.
Provisioning a replica
On the Crunchy Bridge dashboard, select the cluster for which you want to create a replica. Under "Cluster Actions", click "Create Replica".
The following will be automatically set up for the replica based on the original cluster:
- Postgres version
You'll be able to select a different provider, region, and instance (plan) for the replica. The same pricing and billing rates based on plan, storage, high availability, and usage apply for each replica. The cost per month is displayed in a summary along with the region and plan selected.
Detaching a replica
On the cluster dashboard, there is a list of replica actions including resize, detach, and delete. Detaching a replica will create a standalone instance holding the data at the time of the detach action. This is a promotion of the provision from being a replica to being a standalone instance. In many ways, this is similar to the 'fork' action on a main cluster. Once the replica has been detached no data is replicated from the main instance to that instance.
Once you have detached a read replica the name remains the same. You may want to navigate to the settings menu to update the name to reflect that it is no longer a replica.