healthcheck fail on ECS using ALB Target Group

• outline

ALB -> TargetGroup ->Task(Fargate) Health Check

• symptom

Using ECS fargate, state of target groups on ALB is repeating initial > unhealthy > draining.

• resolution 1

increasing health check interval to 300s but it took about 600s for getting healthy state.

• resolution 2

After first successful deployment and modify "healthCheckGracePeriodSeconds" to 30s.

• result

deploy and join the target group as healthy state take under 1 minite.

• reference

https://docs.aws.amazon.com/elasticloadbalancing/latest/application/target-group-health-checks.html
https://docs.aws.amazon.com/ko_kr/AWSCloudFormation/latest/UserGuide/aws-resource-ecs-service.html