What should the DevOps engineer do to troubleshoot the failed deployment?
Ensure that a security group associated with the service allows traffic from the ALB.
Increase the ALB health check grace period for the service.
Increase the service minimum healthy percent setting.
Decrease the ALB health check interval.
Explanations:
Security group settings may block traffic, but this would usually prevent all traffic, not just health checks. Since the issue is with health checks, it’s unlikely related to security group configuration.
Increasing the health check grace period allows the new container tasks more time to start up before the ALB begins checking for health. This can help if the containers are taking longer to initialize after the deployment.
Increasing the minimum healthy percent would make it harder for ECS to replace tasks during a deployment, potentially leading to insufficient resources. The issue seems to be with task startup time rather than service capacity.
Decreasing the ALB health check interval would make the ALB check more frequently, which could actually worsen the problem by prematurely considering tasks unhealthy before they have time to initialize.
I suspect that the answer is:
Increase the ALB health check grace period for the service.