Amazon Neptune
User Guide (API Version 2017-11-29)

Amazon Neptune DB Clusters

An Amazon Neptune DB cluster consists of one or more DB instances and a cluster volume that manages the data for those DB instances. A Neptune cluster volume is a virtual database storage volume. It spans multiple Availability Zones, with each Availability Zone having a copy of the DB cluster data. Two types of DB instances make up a Neptune DB cluster:

  • Primary DB instance – Supports read and write operations and performs all the data modifications to the cluster volume. Each Neptune DB cluster has one primary DB instance.

  • Neptune replica – Connects to the same storage volume as the primary DB instance and supports only read operations. Each Neptune DB cluster can have up to 15 Neptune replicas in addition to the primary DB instance. Maintain high availability by locating Neptune replicas in separate Availability Zones.

    Neptune automatically fails over to a Neptune replica in case the primary DB instance becomes unavailable. You can specify the failover priority for Neptune replicas. Neptune replicas can also offload read workloads from the primary DB instance.

Neptune data is stored in the cluster volume, which is designed for reliability and high availability.