Getting error: consuming input failed: SSL connection has been closed unexpectedly when using RDS Proxy

Based on your description, you're experiencing SSL connection issues when using RDS Proxy with PostgreSQL, but direct connections to the RDS instance work fine. This suggests the issue is specific to the proxy configuration or how your application interacts with it.

The "SSL connection has been closed unexpectedly" error typically occurs when there's an interruption in the SSL/TLS handshake or during an active SSL connection. With RDS Proxy, there are several potential causes:

1. IAM Authentication Rate Limits: Since you're using IAM authentication with your proxy, you might be hitting rate limits for IAM authentication requests. If your application makes many simultaneous connections using IAM auth, try reducing the connection establishment rate.

2. Connection Pooling Behavior: RDS Proxy maintains a pool of database connections and reuses them for client requests. If your application is making certain types of queries that affect the connection state, this might cause issues when the connection is reused.

3. SSL/TLS Configuration Mismatch: There might be a mismatch between the SSL/TLS settings of your application and what the proxy expects. Ensure your psycopg2 driver is configured correctly for SSL connections.

4. Query Timeout Settings: Long-running queries might be timing out at the proxy level before they complete. Check if the queries that fail are particularly complex or time-consuming.

5. Connection Limits: If you're reaching the maximum number of connections allowed by the proxy, it might close connections unexpectedly.

To debug this issue:

• Check your application logs for patterns in which specific queries are failing
• Review the RDS Proxy metrics in CloudWatch for connection errors or throttling
• Verify that your psycopg2 connection parameters are properly configured for SSL
• Consider temporarily increasing logging levels in your application to capture more details about the connection failures
• Test with a simplified application that makes similar queries to isolate the problem

If the issue persists, you might need to adjust your connection pooling settings in RDS Proxy or modify how your application manages database connections.
Sources
Troubleshooting for RDS Proxy - Amazon Relational Database Service
Troubleshooting for RDS Proxy - Amazon Aurora

Hey,

Hope you're keeping well.

RDS Proxy terminates and re-establishes connections on behalf of clients, so when using SSL with PostgreSQL you need to ensure the driver is configured to trust the proxy’s certificate and handle pooled connections correctly. With IAM auth, each new connection triggers a call to rds-db:connect, so a high churn of short-lived connections can cause intermittent failures. In psycopg2, try keeping connections open longer or using a connection pool in your application to reduce handshake frequency. Also verify you’re using the latest AWS RDS CA certificate bundle and that your ECS task can reach both the proxy endpoint and the IAM service without network timeouts.

Thanks and regards,
Taz