Traffic Grayscale

Dubbo provides traffic grayscale service management capabilities, and can configure label routing rules and conditional routing to achieve grayscale publishing without restarting the application.

Dubbo can achieve traffic grayscale through XML configuration, annotation configuration, and dynamic configuration. Here we mainly introduce the dynamic configuration method. For other configuration methods, please refer to the old document Configuration

before the start

Please make sure to run Dubbo-Admin successfully

Background Information

Scenarios of demand changes and version iterations will be encountered during product development. In order to take into account both demand changes and system stability, the release should be as smooth as possible, and the number of affected people should be small to large, and roll back immediately if there is a problem. Dubbo-Admin provides dynamic traffic grayscale capabilities, which can help you bid for new services, release services smoothly, and improve service stability and availability.

Steps

Conditional Routing

1. Log in to the Dubbo-Admin console
2. In the left navigation pane, select Service Governance > Conditional Routing.
3. Click the Create button, in the Create New Routing Rule panel, fill in the rule content, and then click Save.

Detailed Rules

Configuration template

---
scope: application/service
force: true
runtime: true
enabled: true
key: app-name/group+service+version
conditions:
   - application=app1 => address=*:20880
   - method=sayHello => address=*:20880

For traffic grayscale scenarios, you only need to clarify the following issues to know how to write the configuration:

1. To modify the configuration of the consumer application or the configuration of a service.
   • Application: scope: application, key: app-name (you can also use services to specify certain services).
   • Service: scope: service, key:group+service+version.
2. When the routing result is empty, whether to force return.
   • force=false: When the routing result is empty, downgrade the provider whose tag is empty.
   • force=true: When the routing result is empty, an exception will be returned directly.
3. Priority of routing rules
   • priority=1: The priority of routing rules, used for sorting, the higher the priority, the higher the execution, it can be left blank, the default is 0.
4. Whether the configuration takes effect only for certain specific instances.
   • All instances: addresses: ["0.0.0.0"] or addresses: ["0.0.0.0:*"] depends on the side value.
   • Specified instances: addersses[list of instance addresses].
5. The condition rule to modify.
   • => The previous one is the consumer matching condition. All parameters are compared with the consumer’s URL. When the consumer meets the matching condition, the subsequent filtering rules are executed for the consumer.
   • => After that, it is the filter condition of the provider’s address list. All parameters are compared with the provider’s URL, and consumers only get the filtered address list in the end.
   • If the matching condition is empty, it means to apply to all consumers, such as: => host != 10.20.153.11
   • If the filter condition is empty, access is prohibited, such as: host = 10.20.153.10 =>

Label Routing

1. Log in to the Dubbo-Admin console
2. In the left navigation pane, select Service Governance > Label Routing.
3. Click the Create button, and in the Create New Tag Rule pane, fill in the rule content, and then click Save.

Detailed Rules

Configuration template

---
   force: false
   runtime: true
   enabled: true
   key: governance-tagrouter-provider
   tags:
     - name: tag1
       addresses: ["127.0.0.1:20880"]
     - name: tag2
       addresses: ["127.0.0.1:20881"]
  ...

For traffic grayscale scenarios, you only need to clarify the following issues to know how to write the configuration:

1. To modify the configuration of the provider application to which the service belongs.
   • Application: scope: application, key: app-name (you can also use services to specify certain services).
2. When the routing result is empty, whether to force return.
   • force=false: When the routing result is empty, downgrade the provider whose tag is empty.
   • force=true: When the routing result is empty, an exception will be returned directly.
3. Priority of routing rules
   • priority=1: The priority of routing rules, used for sorting, the higher the priority, the higher the execution, it can be left blank, the default is 0.
4. Whether the configuration takes effect only for certain specific instances.
   • All instances: addresses: ["0.0.0.0"] or addresses: ["0.0.0.0:*"] depends on the side value.
   • Specified instances: addersses[list of instance addresses].
5. The tag name to modify.

Result validation

Select the application related to traffic grayscale configuration to trigger the call verification.