Restore Redshift Cluster using Cloud Formation

When restoring a Redshift cluster from a snapshot using CloudFormation, you can indeed create a new cluster with different configurations, including the number of nodes. However, updating the number of nodes after the initial creation will not create a new cluster.

To restore a Redshift cluster from a snapshot using CloudFormation, you would typically use the AWS::Redshift::Cluster resource type in your template. You can specify the snapshot ID and other configuration parameters during the initial creation.

If you need to update the number of nodes in your cluster after it has been created, you can do so by updating your CloudFormation stack. This action will not create a new cluster, but instead will resize the existing cluster.

In CloudFormation, you can use the ResizeClusterMessage property within a scheduled action to change the number of nodes. The NumberOfNodes property allows you to specify the new number of nodes for the cluster. When you update this property and apply the changes to your stack, CloudFormation will initiate a resize operation on your existing cluster rather than creating a new one.

It's important to note that resizing a cluster may cause some interruption to your workloads, depending on whether you're using classic resize or elastic resize. Elastic resize is typically faster and causes less disruption.

Remember that when restoring from a snapshot or resizing a cluster, you need to ensure that the new configuration has enough storage for the existing data. Also, be aware of any constraints related to the cluster version and compatibility when restoring from a snapshot.
Sources
AWS::Redshift::ScheduledAction ResizeClusterMessage - AWS CloudFormation
Restoring a cluster from a snapshot - Amazon Redshift