Instance endpoints for Amazon Aurora

An instance endpoint connects to a specific DB instance within an Aurora cluster. Each DB instance in a DB cluster has its own unique instance endpoint. So there is one instance endpoint for the current primary DB instance of the DB cluster, and there is one instance endpoint for each of the Aurora Replicas in the DB cluster.

The instance endpoint provides direct control over connections to the DB cluster, for scenarios where using the cluster endpoint or reader endpoint might not be appropriate. For example, your client application might require more fine-grained connection balancing based on workload type. In this case, you can configure multiple clients to connect to different Aurora Replicas in a DB cluster to distribute read workloads. For an example that uses instance endpoints to improve connection speed after a failover for Aurora PostgreSQL, see Fast failover with Amazon Aurora PostgreSQL. For an example that uses instance endpoints to improve connection speed after a failover for Aurora MySQL, see MariaDB Connector/J failover support - case Amazon Aurora.

The following example illustrates an instance endpoint for a DB instance in an Aurora MySQL DB cluster.

mydbinstance.c7tj4example.us-east-1.rds.amazonaws.com:3306

Each DB instance in an Aurora cluster has its own built-in instance endpoint, whose name and other attributes are managed by Aurora. You can't create, delete, or modify this kind of endpoint. You might be familiar with instance endpoints if you use Amazon RDS. However, with Aurora you typically use the writer and reader endpoints more often than the instance endpoints.

In day-to-day Aurora operations, the main way that you use instance endpoints is to diagnose capacity or performance issues that affect one specific instance in an Aurora cluster. While connected to a specific instance, you can examine its status variables, metrics, and so on. Doing this can help you determine what's happening for that instance that's different from what's happening for other instances in the cluster.

In advanced use cases, you might configure some DB instances differently than others. In this case, use the instance endpoint to connect directly to an instance that is smaller, larger, or otherwise has different characteristics than the others. Also, set up failover priority so that this special DB instance is the last choice to take over as the primary instance. We recommend that you use custom endpoints instead of the instance endpoint in such cases. Doing so simplifies connection management and high availability as you add more DB instances to your cluster.