Memorystore is zonal, meaning each Memorystore instance is only available within a zone, or accessible from other zones within the same region. For high-availability, create a Standard tier instance, which includes a failover replica in a separate zone.
All Memorystore instances can only be accessed by a private IP on a VPC network. You can connect to a Memorystore instance from different Google Cloud Platform computing resources differently. In general, VM-based products (Compute Engine, Kubernetes Engine, and App Engine Flexible) requires the VM to be on the same VPC, and Serverless products requires VPC Service Connector.
Because Memorystore is protocol compatible. You can use existing Spring Boot integration with Redis and Memcached as-is.