Target groups: unavailable instance did not switch to unhealthy

Question

We had an instance that despite being unreachable did not switch from healthy to unhealthy.
In the instance there is a tomcat and nginx web application as a reverse proxy.
In the tomcat and nginx logs we did not find any calls from the healthcheck service during the down period,
but calls resumed smoothly as soon as the instance resumed working smoothly
Would anyone be able to explain why the instance has not become unhealthy?

Answer

Hi Andrea,

I understand that you would like to know why the instance became unresponsive without it switching to an unhealthy status.Please correct me if I misunderstood.

It could be a Load Balancer health check fetch issue, Please note that longer intervals may mean that the Load Balancer will take longer to fetch health checks. Issues can occur and resolve in between, before the next health check and target still be showing as healthy. I would recommend that you check your configurations to understand your issue.

For further assistance on the issue please consider contact AWS customer support[2].

You can refer to the following document on troubleshooting issues:

[1]https://aws.amazon.com/premiumsupport/knowledge-center/elb-fix-failing-health-checks-alb/

[2]https://aws.amazon.com/contact-us/

I hope you find this information useful.

Target groups: unavailable instance did not switch to unhealthy

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