Valkey Mirroring

Valkey Mirroring allows writes from one Valkey cluster to be replicated to another, by deploying a lightweight proxy called Shotover, co-located with the Valkey nodes, which replicates writes to a second, remote Valkey cluster.

How to create a Valkey Mirroring cluster

1. On the console, create a Valkey cluster of any size as you normally would and wait for it to enter the Running state.

1. Click your cluster from the left side bar, and you will find a option  – Add Data Centre

1. Clicking Add Data Centre will take you to the Add Data Centre page, where you can create a new data centre for your Valkey cluster by filling in the fields necessary

1. 1. Make sure both data centres are similarly sized, as they will be expected to hold the same amount of data.
2. Once complete, the second Valkey data centre will begin to provision in the selected region, wait for it to enter the RUNNING state.

How to use a Valkey Mirroring cluster

1. Once we have a running Valkey cluster with multiple mirroring data centres, we need to configure our client applications to send Valkey commands through Shotover application.
2. In the Connection Info page, we can find the connection details, which describes the various ways we may connect to our Valkey cluster
3. We can find a tab page titled Shotover Proxy, which exposes a new port & DNS name that our client applications must use to send Valkey commands in order for Valkey Mirroring to work.

Limitations

• The mirroring method is only suitable for use cases where the data has a short time to live (TTL). This is due to the fact that the method for Valkey Mirroring is simply asynchronous, on-the-fly replication, so if anything goes wrong there could be missing data on the secondary/standby cluster. There is no record of what has or hasn’t been replicated. The short TTL is so any missing data will matter less, as the data would expire soon anyway. It is hard to put an exact figure on how long your short TTL should be, as it depends on a multitude of factors, but we would say: in the range of minutes.