Filter

Dubbo-go filters are interceptor-style extensions around RPC invocation. They are typically used to add cross-cutting behavior such as authentication, rate limiting, logging, tracing, metrics, generic invocation adaptation, and graceful shutdown handling.

Getting Started

The recommended approach is to import only the filters your application needs.

package demo

import _ "dubbo.apache.org/dubbo-go/v3/filter/echo"
import _ "dubbo.apache.org/dubbo-go/v3/filter/generic"

If you prefer the legacy all-in-one import, you can still use:

package demo

import _ "dubbo.apache.org/dubbo-go/v3/filter/filter_impl"

Where Filters Apply

Dubbo-go distinguishes between two filter chains:

• service.filter: provider-side filters
• reference.filter: consumer-side filters

The built-in defaults are defined in common/constant/default.go.

Built-in Filters

Core

• echo: echo health check support
• generic: consumer-side generic invocation filter
• generic_service: provider-side generic service filter
• graceful_shutdown: graceful shutdown behavior for provider and consumer paths

Traffic Control

• active: active request counting
• exec_limit: provider-side execute concurrency limiting
• tps: TPS limiting
• adaptivesvc: adaptive service filter
• polaris/limit: Polaris rate limiting
• sentinel: Sentinel integration for provider and consumer traffic protection

Security

• token: token-based request validation
• auth: request signing and authentication
• seata: Seata distributed transaction propagation

Observability

• accesslog: invocation access logging
• metrics: metrics collection
• tracing: tracing integration
• otel/trace: OpenTelemetry tracing integration

Extension Note

• hystrix: moved to dubbo-go-extensions

Common Usage

In practice, filters are usually enabled through application config instead of being called directly from business code. Typical examples:

• enable a provider filter through service.filter
• enable a consumer filter through reference.filter
• import the filter package so it registers itself via extension.SetFilter(...)

Notes

• Importing a filter package registers it; the filter still needs to be enabled by the corresponding consumer/provider configuration path when applicable.
• Some filter names differ slightly from their package directory because the runtime key is defined in common/constant/key.go.
• Filters under subdirectories such as otel/trace and polaris/limit are still ordinary Dubbo-go filters; the subdirectory just reflects feature grouping.