Dubbo proxy
- Statistics
- Implement custom filter based on the dubbo proxy filter

Dubbo proxy

The dubbo proxy filter decodes the RPC protocol between dubbo clients and servers. the decoded RPC information is converted to metadata. the metadata includes the basic request ID, request type, serialization type, and the required service name, method name, parameter name, and parameter value for routing.

v2 API reference
This filter should be configured with the name envoy.filters.network.dubbo_proxy.

Statistics

Every configured dubbo proxy filter has statistics rooted at redis.. with the following statistics:

Name	Type	Description
request	Counter	Total requests
request_twoway	Counter	Total twoway requests
request_oneway	Counter	Total oneway requests
request_event	Counter	Total event requests
request_decoding_error	Counter	Total decoding error requests
request_decoding_success	Counter	Total decoding success requests
request_active	Gauge	Total active requests
response	Counter	Total responses
response_success	Counter	Total success responses
response_error	Counter	Total responses that protocol parse error
response_error_caused_connection_close	Counter	Total responses that caused by the downstream connection close
response_business_exception	Counter	Total responses that the protocol contains exception information returned by the business layer
response_decoding_error	Counter	Total decoding error responses
response_decoding_success	Counter	Total decoding success responses
response_error	Counter	Total responses that protocol parse error
local_response_success	Counter	Total local responses
local_response_error	Counter	Total local responses that encoding error
local_response_business_exception	Counter	Total local responses that the protocol contains business exception
cx_destroy_local_with_active_rq	Counter	Connections destroyed locally with an active query
cx_destroy_remote_with_active_rq	Counter	Connections destroyed remotely with an active query

Implement custom filter based on the dubbo proxy filter

If you want to implement a custom filter based on the dubbo protocol, the dubbo proxy filter like HTTP also provides a very convenient way to expand, the first step is to implement the DecoderFilter interface, and give the filter named, such as testFilter, the second step is to add your configuration, configuration method refer to the following sample

filter_chains:
- filters:
  - name: envoy.filters.network.dubbo_proxy
    config:
      stat_prefix: dubbo_incomming_stats
      protocol_type: Dubbo
      serialization_type: Hessian2
      route_config:
        name: local_route
        interface: org.apache.dubbo.demo.DemoService
        routes:
        - match:
            method:
              name:
                exact: sayHello
          route:
            cluster: user_service_dubbo_server
      dubbo_filters:
      - name: envoy.filters.dubbo.testFilter
        config:
          "@type": type.googleapis.com/google.protobuf.Struct
          value:
            name: test_service
      - name: envoy.filters.dubbo.router