Traffic Control on Apache Dubbo

Affinity Router

Mon, 01 Jan 0001 00:00:00 +0000

Condition Router

Mon, 01 Jan 0001 00:00:00 +0000

Related samples:

Dynamic condition router: dubbo-go-samples/router/condition
Static condition router: dubbo-go-samples/router/static_config/condition

How to use

Prerequisites

Docker and Docker Compose environment to deploy Nacos registry.
Nacos Version 2.x+
Go 1.23+

Run Nacos

Follow this instruction to install and start Nacos server.

Condition router

Similar to the Tag Router, the condition router offers more advanced traffic control capabilities. It uses consumer => provider expressions to manage traffic for both providers and consumers.

Expression example:

host = 127.0.0.1 => host = 127.0.0.1, 192.168.1.1

Script Router

Mon, 01 Jan 0001 00:00:00 +0000

Sample source: dubbo-go-samples/router/script.

Script Router runs on the consumer and uses a JavaScript script to filter candidate providers. It currently supports application-scoped dynamic rules. Use it when routing decisions depend on runtime information such as a provider URL, RPC method, or invocation attachment, for example to pin traffic to a port or select instances by tenant or gray-release marker.

For simple matching by address, method, or application name, prefer Condition Router. Script Router is more expressive, but scripts cost more to execute and maintain. Keep production scripts small and verify that they always return callable providers.

Tag Router

Mon, 01 Jan 0001 00:00:00 +0000

Related samples:

Dynamic tag router: dubbo-go-samples/router/tag
Static tag router: dubbo-go-samples/router/static_config/tag

How to use

Prerequisites

Docker and Docker Compose environment to deploy Nacos registry.
Nacos Version 2.x+
Go 1.23+

Run Nacos

Follow this instruction to install and start Nacos server.

Tag router

The tag router enables traffic control based on tags. It is commonly used for canary releases (tag the new-version instances so that only requests carrying the tag are routed to them) and environment isolation (instances in different lanes are distinguished by tags to keep traffic from crossing environments). The following is the example code.

Sentinel Rate Limiting and Downgrade

Mon, 01 Jan 0001 00:00:00 +0000

Dubbo-go provides a built-in rate limiting component, allowing users to adjust rate limiting values and post-limiting behaviors according to their business scenarios. The specifics can be defined and implemented in TpsLimiter. Users can set a simple rate limiting strategy on the server side in a manner similar to the following:

server.WithTpsLimiter("method-service") // Currently supports implementations like method-service, polaris, etc.
server.WithTpsLimiterXxx() // Set rate limiting related thresholds, please fill in according to the specific method
//tps.limit.strategy: "slidingWindow"
//tps.limit.rejected.handler: "default"
//tps.limit.interval: 1000
//tps.limit.rate: 3

The built-in rate limiting strategy in Dubbo-go is relatively simple. For more complex scenarios, we recommend using professional third-party frameworks like Sentinel to achieve richer and more flexible rate limiting strategies.