Why Am I Seeing the Message "No backend available"?
- Check whether the backend service is accessible, and modify the backend service if it is inaccessible.
- Check the ECS security group configurations of the backend service and verify that the required port has been enabled.
- Check whether ACL configurations of the VPC restrict the communication between the API gateway and the subnet where the backend service is located.
- If you use a VPC channel, check whether the service port, health check port, and backend servers of the VPC channel have been correctly configured.