AWS ECS service Tasks getting replaced with (reason Request timed out)

Your steps from 1 to 7 almost no thing do with the error.

service example-service (instance i-016b0a460d9974567) (port 1047) is unhealthy in target-group example-service due to (reason Request timed out)

The error is very clear, you ECS service is not reachable to Load balancer health check.

Target Group Unhealthy

When this is the case, go straight and check the container SG, Port, application status or health status code.

Possible reason

• There might be the case, there is no route Path /healthcheck in the backend service
• The status code from /healthcheck is not 200
• Might be the case that target port is invalid, configure it correctly, if an application running on port 8080 or 3000 it should be 3000 or 8080
• The security group is not allowing traffic on the target group
• Application is not running in the container

These are the possible reason when there is a timeout from health check.

I faced the same issue of ( Reason request timeout ).I managed to solve it by updating my security-group inbound rules.Currently, there was no rule defined in Inbound rules so I add general allow-all traffic for the ipv4 rule for the time being because I was in development at that time.