This page gives an overview of multiple VPC networking for Memorystore for Redis Cluster. In situations where you only need one VPC network, we recommend (but don't require) using a service connection policy to provision your network, as explained in Networking overview.
Setting up networking for multiple VPC networks requires Memorystore users to configure and register up Private Service Connect (PSC) connections.
For a tutorial on setting up multiple VPCs using only user-registered connections, see Provision a new instance to use multiple VPC networks.
For a tutorial on setting up multiple VPCs for instances provisioned with automatically-registered PSC connections, see Configure an existing instance to use multiple VPC networks.
Private Service Connect connections
This section explains essential information about PSC connections for Memorystore.
PSC connection basics
For Memorystore, a PSC connection consists of two fundamental items:
- An IP address
- An established connection between a PSC endpoint and a Memorystore instance's service attachment
PSC connection types
When using Memorystore for Redis Cluster, PSC connections fall into two categories: automatically-registered and user-registered. A Memorystore for Redis Cluster instance is compatible with both types.
User-registered PSC connections: These are self-created and self-registered PSC connections. For Memorystore, user-registered PSC connections are needed for multiple VPC networking setups.
Self-managing these connections has the benefit of giving you control over the subnets, IP addresses, and forwarding rules used to create them. For these connections, you are responsible for their lifecycle (including creating, registering, and deleting them).
Automatically-registered PSC connections: These are connections created and registered by PSC service connectivity automation for your Memorystore instance. When you create/delete a Memorystore instance, your service connection policy manages the lifecycle of the associated PSC connection by automatically creating/registering/deleting it.
If you already have a Memorystore instance that you've been using, and you want to connect additional VPC networks, you probably have automatically registered connections. If you want to keep these connections because your existing application uses them, you can keep them and only add user-registered PSC connections for new VPCs.
Application connection requirements
In order to connect your application using a multiple VPC networking setup, Memorystore has networking requirements you must meet.
Each VPC network you connect to your Memorystore instance needs to have two PSC connections (either user-registered or automatically-registered). One connection is the discovery connection used for your client to establish connection to the cluster. The other connection is reserved for internal usage by the Memorystore backend.
For information about connecting your client for an instance that uses only user-registered PSC connections, see Set up a client connection (user-registered connections).
For information about connecting your client for an instance that uses an automatically-registered PSC connection, see Set up a client connection (automatically-registered connection).
For more general information about setting up connections to services through PSC endpoints, see Access published services through endpoints.
Limitations
- You can have between 1 and 20 VPC networks connected to a single Memorystore instance, and no more than 40 PSC connections in total
- To delete a Memorystore instance connected with user-registered PSC connections, you must delete and deregister the PSC connections first.