Surfacing the metric on the host itself, and not buried in the EBS volume, would be a good start.
WRT alerting - if you're at 0 credits; your performance on something obviously under load is now being degraded, why not surface an alert on it? AWS already has a configurable events system in place for EC2 - this seems like a good fit.
WRT alerting - if you're at 0 credits; your performance on something obviously under load is now being degraded, why not surface an alert on it? AWS already has a configurable events system in place for EC2 - this seems like a good fit.