Amazon Web Services DVA-C02 Exam With Confidence Using Practice Dumps

The solution that will meet the requirements with the least development effort is to set the image resize Lambda function as a destination of the avatar generator Lambda function for the events that fail processing. This way, the fallback mechanism is automatically triggered by the Lambda service without requiring any additional components or configuration. The other options involve creating and managing additional resources such as queues, topics, state machines, or rules, which would increase the complexity and cost of the solution.

The requirement is specifically to have ECS automatically restore the last known good deployment when a new deployment fails, while the service is using the rolling update deployment type. Amazon ECS supports this through the deployment circuit breaker with the option to rollback on failures.

When enabled, the deployment circuit breaker monitors the deployment and detects failure conditions such as tasks repeatedly failing health checks, not reaching steady state, or being unable to start successfully. With rollback enabled, ECS automatically stops the failing deployment and reverts the service to the most recently completed (stable) task definition, restoring service stability without manual intervention.

Option D matches exactly: keep the rolling deployment type and enable circuit breaker + rollback. This is minimal change and directly addresses the behavior observed.

Options A and B are unrelated: service autoscaling adjusts desired count based on metrics and does not roll back failed deployments.

Option C could also achieve rollback behavior, but switching to blue/green introduces additional components (AWS CodeDeploy integration, target groups, and traffic shifting), which is unnecessary when the requirement can be met within rolling deployments.

Therefore, enabling the ECS deployment circuit breaker with rollback on failures for a rolling deployment is the correct solution.

Requirement Summary:

WebSocket-based messaging app using API Gateway WebSocket APIs

Need to:

Identify clients repeatedly connecting/disconnecting

Be able to remove problematic clients

Evaluate Options:

A. Switch to HTTP APIs

HTTP APIs don’t support WebSocket connections

B. Switch to REST APIs

REST APIs are not compatible with WebSockets

C. Use the callback URL to disconnect clients

⚠️ Possible, but not a direct option

Callback URLs are used for sending messages to connected clients, not for disconnecting

D. Track client status in ElastiCache

Good solution: Store and update connection state (connected, disconnected, timestamps)

Helps track abuse or reconnections

E. Implement $connect and $disconnect routes

Required to capture connection lifecycle events

These can be used to log/store client behavior and decide on removal

WebSocket routes in API Gateway:

Managing WebSocket connections: