EKS upgraded from 1.21 to 1.22

Can you please provide more details of your error. Looks like it's application specific, did you check deprecation guide for moving from 1.21 to 1.22 https://kubernetes.io/docs/reference/using-api/deprecation-guide/. Make sure your application is not using any deprecated API versions.

Hello,

So the error could be due to many reasons. In order to find a cause behind the error I would suggest you to perform below set of actions and see if that help you in finding the issue.

1. kubectl get pods -o wide ---> Look for the application pods which you are trying to connect to
2. kubectl get svc ---> look for the service which is front ending the pods
3. kubectl describe svc <service-name> ---> Look for the endpoints in the output and compare if they are reffering to right pods by matching the IP.
4. kubectl get ing --> Look for the ingress which has the above service as backend.
5. kubectl describe ing <ingress-name> ---> Check for the events in the output and see if there is any error.
6. In AWS console, go the the load balancer section and look for the target group and check for the registered targets, are they having the same IP as your pods(in case of IP type target) or node IP( in case of instance type target)
7. Check if the targets are healthy?
8. If you do not see any targets in the target group, look for the controller logs.

I hope above steps will help you in narrowing down the issue. Please let me know if there is any error which you are not able to figure out or above steps does not helps you.