Nacos

1 Prerequisites

• Understand Basic Development Steps of Dubbo
• Install and start Nacos

When Dubbo uses version 3.0.0 or above, Nacos version 2.0.0 or above is required. Please refer to nacos registry for Nacos version compatibility.

2 Instructions

2.1 Add Maven Dependency

If the project has already enabled Nacos as a registry, no additional configuration is required.

If Nacos registry is not enabled, please refer to Add Nacos dependency for registry.

2.2 Enable Nacos Configuration Center

<dubbo:config-center address="nacos://127.0.0.1:8848"/>

or

dubbo
  config-center
    address: nacos://127.0.0.1:8848

or

dubbo.config-center.address=nacos://127.0.0.1:8848

or

ConfigCenterConfig configCenter = new ConfigCenterConfig();
configCenter.setAddress("nacos://127.0.0.1:8848");

For address format, please refer to Nacos Registry - Enable Configuration

3 Advanced Configuration

To enable authentication, please refer to Nacos Registry - Enable Authentication

3.1 Externalized Configuration

3.1.1 Global Externalized Configuration

1. Application enable config-center configuration

dubbo
  config-center
    address: nacos://127.0.0.1:2181
    config-file: dubbo.properties # optional

config-file - Key for global externalized configuration file, default is dubbo.properties. It represents the key in the configuration center when storing the Dubbo configuration file remotely. It is generally not recommended to modify this configuration.

2. Add Configuration to Nacos Server

dataId is dubbo.properties, group is the same as config-center, default is dubbo if not set.

3.1.2 Application-Specific Externalized Configuration

1. Application enable config-center configuration

dubbo
  config-center
    address: nacos://127.0.0.1:2181
    app-config-file: dubbo.properties # optional

app-config-file - Key for the application-specific externalized configuration file, such as app-name-dubbo.properties, configured only when needing to override the global externalization config-file.

2. Add Configuration to Nacos Server

dataId is dubbo.properties, group is the application name demo-provider.

3.2 Set Group and Namespace

dubbo
  config-center
    address: zookeeper://127.0.0.1:2181
    group: dubbo-cluster1
    namespace: dev1

For the configuration center, group and namespace should be consistent across the company (cluster) and avoid different values for different applications.

3.3 Nacos Extended Configuration

For more Nacos sdk/server supported parameter configurations, refer to Nacos Registry - More Configurations

4 Traffic Governance Rules

For Nacos, all traffic governance rules and externalized configurations should be globally visible, thus applications in the same logical cluster must use the same namespace and group. The default value for namespace is public and the default value for group is dubbo. Applications must not modify the namespace and group without maintaining global consistency.

Changes to traffic governance rules are recommended to be made through dubbo-admin; for more details, see Dubbo’s supported traffic governance capabilities.

There are various types of traffic governance rules, and different types of rules have different suffixes for dataId:

• configurators override rules
• tag-router tag routing and condition-router condition routing