When applications span multiple zones, service-to-service calls may cross zone boundaries, adding network latency and increasing HTTP response times. The Intra-zone Provider First feature in Enterprise Distributed Application Service (EDAS) routes consumer requests to providers in the same zone first, reducing latency and improving response times.
EDAS supports this feature for Spring Cloud, Dubbo, and High-speed Service Framework (HSF) applications deployed in Elastic Compute Service (ECS) clusters.
How it works
In a multi-zone deployment, a consumer application may call a provider in a different zone. This cross-zone call travels over a longer network path, which increases HTTP response time.
After you enable the Intra-zone Provider First feature on the provider application, consumer applications prioritize providers deployed in the same zone. The call stays within a single zone, so network latency drops and HTTP response time improves.
If no provider is available in the same zone, the consumer automatically falls back to a provider in another zone, so service availability is not affected.
Threshold behavior
The feature uses a threshold parameter to decide whether same-zone routing applies. You set the threshold to a value between 0 and 100. The feature takes effect only when the following condition is met:
(instances in current zone / total instances across all zones) * 100 > thresholdIf the ratio falls below the threshold, same-zone routing is disabled and requests are distributed across all available zones.
| Threshold value | Behavior |
|---|---|
| 0 | Same-zone routing is always active (any non-zero instance count qualifies) |
| 100 | Same-zone routing is never active (the ratio can never exceed 100) |
| 1--99 | Same-zone routing activates when the zone's share of instances exceeds the threshold |
Prerequisites
Before you begin, make sure that you have:
An EDAS application deployed in an ECS cluster across multiple zones
An application that uses Spring Cloud, Dubbo, or HSF as its microservice framework
Enable Intra-zone Provider First
Log on to the EDAS console.
In the left-side navigation pane, choose Application Management > Applications.
In the top navigation bar, select a region. In the upper part of the Applications page, select a microservice namespace, then click the name of the application deployed in an ECS cluster.
On the Basic Information tab, locate the Application Settings section. Turn on Intra-zone Provider First and specify a threshold.
NoteThe feature takes effect only when the ratio of instances in the current zone to the total number of instances exceeds the specified threshold. Valid values: 0 to 100.
Verify the result
After you enable the feature, compare the HTTP response times for service calls against the previous cross-zone baseline. A decrease in response time confirms that intra-zone routing is active.