Aurora PostgreSql Multi-AZ database giving read-only error after cluster failed over

The error message you're encountering indicates that your application is attempting to perform a write operation (specifically an UPDATE) on a read-only replica database after a failover event in your Aurora PostgreSQL cluster. This behavior is expected because after a failover, the replica databases become read-only until they are promoted to become the new read/write primary.

To resolve this error, you can implement one of the following approaches:

1. *Retry Logic: Implement retry logic in your application to handle the scenario where a write operation fails due to the replica being read-only. When your application detects a failure due to a read-only transaction, it can retry the operation after a short delay.

2. Endpoint Switching: Instead of using a single cluster endpoint for both read and write operations, use separate endpoints for reads and writes. Amazon Aurora provides cluster endpoints that automatically route read and write traffic to the appropriate instances. By using separate endpoints, your application can avoid attempting writes on read-only replicas.

3. Detecting Read-Only Mode: Implement logic in your application to detect when a replica has been promoted to the primary role after a failover event. You can use AWS CloudWatch metrics or Aurora events to monitor the cluster's state and adjust your application's behavior accordingly.

4. Handle Failover Events: Configure your application to handle failover events gracefully. This may involve closing existing database connections and reconnecting to the new primary instance after a failover. Ensure that your application's connection pooling and retry mechanisms are robust enough to handle failover events without causing disruptions to your users.

By implementing one or more of these approaches, you can mitigate the impact of read-only errors during failover events in your Amazon Aurora PostgreSQL cluster and ensure the reliability of your application.