When multiple versions of a Dubbo application coexist in a Kubernetes cluster, service calls are distributed randomly by default. During a canary release, traffic intended for a new version may reach the old version -- or vice versa -- at any point in the call chain. End-to-end traffic adjustment in Enterprise Distributed Application Service (EDAS) solves this by isolating application versions into independent runtime environments called lanes and routing request traffic to specific versions based on rules you define.
How traffic routing works
Consider an e-commerce order placement scenario with the following call chain:
Ingress application -> Transaction center -> Commodity center -> Inventory center
The ingress application is the entry point for traffic and can also be a microservice gateway. Both the transaction center and the commodity center have two versions deployed: V1.0 and V2.0. To validate the new versions during a canary release:
Request traffic that matches specific traffic adjustment rules at the ingress application is routed to V2.0 applications throughout the entire call chain.
All remaining traffic is routed to V1.0 (the production version).
This keeps V2.0 traffic fully isolated from V1.0 traffic across the entire call chain, not just at a single service.
Key concepts
Concept | Definition |
Ingress application | The entry point for traffic in a microservice system. An ingress application can be a service gateway built on Spring Cloud Gateway or Spring Cloud Netflix Zuul, or a Spring Boot, Spring MVC, or Dubbo application. |
Lane | An isolated runtime environment for applications of the same version. Only request traffic that matches the traffic adjustment rules of a lane is routed to the applications in that lane. Applications and lanes have a many-to-many relationship: an application can belong to multiple lanes, and a lane can contain multiple applications. |
Lane group | A collection of lanes used to separate different teams or scenarios. |
Quotas and limits
After you configure end-to-end traffic adjustment for applications, those applications no longer support canary release.
If you build an ingress gateway based on Spring Cloud Gateway, use version 2.1.x or later.
Lane group and lane quotas depend on your EDAS edition:
Edition
Lane groups (all regions)
Lanes per lane group
Standard Edition
1
5
Professional Edition
10
50
Platinum Edition
10
50
All editions other than Professional Edition and Platinum Edition are Standard Edition.
Lane group and lane quotas cannot be increased. To request a quota increase, submit a ticket.