The throttling and degradation feature of Enterprise Distributed Application Service (EDAS) handles slow system responses or crashes caused by high pressure on the backend core services. This feature is generally used in high-traffic scenarios, such as flash sales, shopping sprees, major promotions, and prevention of empty box scams.

Throttling

This feature is used to control the traffic threshold or adjust the traffic ratio. It controls frontend website traffic to protect the backend core systems and prevent service unavailability. By adjusting the traffic threshold, the throttling feature controls the maximum traffic volume of the system to ensure secure and stable system operation.

How it works

After the throttling code is configured for a provider and a throttling policy is configured in EDAS, the provider enables the throttling feature. When a consumer calls services of the provider, all access requests are calculated by the throttling module. If the call volume of the consumer exceeds the preset threshold in a specific period, the throttling policy is triggered.

Degradation

In EDAS, degradation refers to the reduction of the call priority of downstream non-core providers that have timed out. This ensures the availability of core applications for consumers.

How it works

After the degradation code is configured for a consumer and a degradation policy is configured in EDAS, this consumer enables the degradation feature. When this consumer calls services of a provider, if the response time of the provider exceeds the preset threshold, the degradation policy is triggered.