Replication with Amazon Neptune - Amazon Neptune

Replication with Amazon Neptune

Amazon Neptune provides several options for replicating data between Neptune DB clusters and other database instances. The replication technique that you choose depends on your particular needs.

Neptune Replicas

Neptune replicas are independent endpoints in a Neptune DB cluster. They are best used for scaling read operations and increasing availability. You can distribute up to 15 Neptune replicas across the Availability Zones that a DB cluster spans within an AWS Region. The DB cluster volume is made up of multiple copies of the data for the DB cluster. However, the data in the cluster volume is represented as a single logical volume to the primary instance and to Neptune replicas in the DB cluster.

As a result, all Neptune replicas return the same data for query results with minimal replica lag. This replica lag is usually much less than 100 milliseconds after the primary instance writes an update. Replica lag varies depending on the rate of database change. That is, during periods in which a large amount of write operations occur for the database, you might see an increase in replica lag.

Neptune replicas work well for read scaling because they are fully dedicated to read operations on your cluster volume. Write operations are managed by the primary instance. Because the cluster volume is shared among all DB instances in your DB cluster, minimal additional work is required to replicate a copy of the data for each Neptune replica.

To increase availability, you can use Neptune replicas as failover targets. That is, if the primary instance fails, a Neptune replica is promoted to the primary instance. There is a brief interruption during which read and write requests made to the primary instance fail with an exception, and the Neptune replicas are rebooted. If your Neptune DB cluster doesn't include any Neptune replicas, your DB cluster is unavailable for the duration that it takes your DB instance to recover from the failure event. However, promoting a Neptune replica is much faster than re-creating the primary instance.

For high-availability scenarios, we recommend that you create one or more Neptune replicas. These should be of the same DB instance class as the primary instance and in different Availability Zones for your Neptune DB cluster. For more information about Neptune replicas as failover targets, see Fault Tolerance for a Neptune DB Cluster.

Note

You can't create an encrypted Neptune replica for an unencrypted Neptune DB cluster. You can't create an unencrypted Neptune replica for an encrypted Neptune DB cluster.

For details on how to create a Neptune replica, see Creating a Neptune Replica Using the Console.