The CloudStatus service reports EC2 health based on EC2's network availability and compute availability. A health status of Service Failure indicates intermittent network failures or an availability zone failure.
The health of an AWS service is an indicator of its current and recent quality of service. Health reflects the availability of a service and the performance of key service operations, invoked from both inside and outside the cloud. Service health is indicated on charts as:
Healthy—indicates full health and satisfactory performance
Issues—indicates partial health, instances of less than satisfactory performance, or both
Service Failure—indicates service not available, or poor health