Aurora: The Custom Endpoints

 

In Amazon Aurora (a MySQL- and PostgreSQL-compatible relational database engine), custom endpoints allow twtech to create a tailored connection endpoint that routes traffic to a specific subset of Aurora DB instances in a Aurora cluster. This is especially useful in Aurora clusters with multiple instances, such as those used for read scaling or application-based workload separation.

The Custom Endpoint in Aurora

A custom endpoint is a user-defined endpoint that twtech associates with one or more Aurora reader instances in a cluster. It provides a logical endpoint (DNS name) that applications can use to target specific instances for reads.

·        It does not support write operations.

·        Custom endpoints route traffic only to reader nodes, never to the writer.

 Use Cases for Custom Endpoints

1.     Read Traffic Segmentation

o   Direct specific workloads to certain readers (e.g., reporting, analytics).

2.     Application Sharding

o   Route different microservices to different DB instances.

3.     Failover Isolation

o   Prevent specific applications from being impacted during failover.

4.     Performance Optimization

o   Isolate heavy queries on a designated replica.

 Default Aurora Endpoints (for comparison)

Endpoint Type	Description	Use Case
Cluster Endpoint	Routes to the writer instance.	For write/read operations.
Reader Endpoint	Routes to any available reader.	For read scaling.
Instance Endpoint	Routes to a specific instance.	For troubleshooting/testing.

 Creating a Custom Endpoint

twtech can create custom endpoints using:

·        AWS Management Console

·        AWS CLI

·        RDS API

CLI Example:

# bash

 aws rds create-db-cluster-endpoint \

    --db-cluster-identifier twtech-aurora-cluster \

    --db-cluster-endpoint-identifier analytics-endpoint \

    --endpoint-type READER \

    --static-members twechdbinstance2 twtechdbinstance3 \

    --tags Key=Purpose,Value=Analytics

 Key Parameters

·        --db-cluster-endpoint-identifier: Custom name for the endpoint.

·        --endpoint-type: Must be READER (only type supported).

·        --static-members: List of DB instances for routing.

·        --excluded-members: Exclude specific DB instances from dynamic routing.

 Limitations

·        Only Aurora MySQL and Aurora PostgreSQL support custom endpoints.

·        Custom endpoints are read-only—write traffic will fail.

·        twtech can have up to 5 custom endpoints per cluster.