envoy 路由重试策略配置

[huangshuwei]

前言

按照上一篇的配置,如果使用流模式我们会发现一个问题，如果推送服务挂了再恢复，我们的浏览器是无法再收到推送消息的，直到浏览器刷新或者代理服务重启才行。

重试策略

目前没有发现可以通过 grpc-web 代码方式解决上面的问题，在官网发现了路由重试策略的介绍，我们可以通过 retry_on配置重试的条件，通过num_retries配置重试的次数。

修改如下配置：

# 省略
route:
      cluster: greeter_service
      timeout: 0s
      retry_policy:
        #retry_on: connect-failure,refused-stream,unavailable,cancelled,retriable-status-codes
        retry_on: 5xx
        num_retries: 10 
      max_stream_duration:
        grpc_timeout_header_max: 0s
# 省略

完整配置如下

admin:
  access_log_path: /tmp/admin_access.log
  address:
    socket_address: { address: 0.0.0.0, port_value: 9902 }

static_resources:
  listeners:
    - name: listener_0
      address:
        socket_address: { address: 0.0.0.0, port_value: 8080 }
      filter_chains:
        - filters:
            - name: envoy.filters.network.http_connection_manager
              typed_config:
                "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
                codec_type: auto
                stat_prefix: ingress_http
                route_config:
                  name: local_route
                  virtual_hosts:
                    - name: local_service
                      domains: ["*"]
                      routes:
                        - match: { prefix: "/" }
                          route:
                            cluster: greeter_service
                            timeout: 0s
                            retry_policy:
                              #retry_on: connect-failure,refused-stream,unavailable,cancelled,retriable-status-codes
                              retry_on: 5xx
                              num_retries: 10
                            max_stream_duration:
                              grpc_timeout_header_max: 0s
                      cors:
                        allow_origin_string_match:
                          - prefix: "*"
                        allow_methods: GET, PUT, DELETE, POST, OPTIONS
                        allow_headers: keep-alive,user-agent,cache-control,content-type,content-transfer-encoding,custom-header-1,x-accept-content-transfer-encoding,x-accept-response-streaming,x-user-agent,x-grpc-web,grpc-timeout
                        max_age: "1728000"
                        expose_headers: custom-header-1,grpc-status,grpc-message
                http_filters:
                  - name: envoy.filters.http.grpc_web
                  - name: envoy.filters.http.cors
                  - name: envoy.filters.http.router
  clusters:
    - name: greeter_service
      connect_timeout: 0.25s
      type: logical_dns
      http2_protocol_options: {}
      lb_policy: round_robin
      # win/mac hosts: Use address: host.docker.internal instead of address: localhost in the line below
      load_assignment:
        cluster_name: cluster_0
        endpoints:
          - lb_endpoints:
              - endpoint:
                  address:
                    socket_address:
                      address: 0.0.0.0 # 此处换成你需要代理的 grpc 服务地址
                      port_value: 8090