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gRPC服务发现与服务治理技术选型

gRPC服务发现与服务治理,目前常见解决方案有以下两种

Nginx + consul + consul-template
Envoy

本文粗略讲解一下两种方案的优缺点

1. nginx + consul + consul-template

实现步骤

grpc微服务注册到consul, consul会定时ping grcp微服务
当consul节点有更新时, consul-template生成nginx-consul.conf文件
nginx reload完成服务更新, 当有请求时upstream转发到grpc微服务

nginx-consul.conf大致如下

# nginx需要安装grpc模块
upstream User {
    server 127.0.0.1:17000;
    server 127.0.0.1:18000;
}
server {
    listen       19000 http2;
    server_name  _;
    
    location /protobuf.User {
        default_type application/grpc;
        grpc_pass grpc://User;
    }
}	
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优点

简单易用,文档丰富

缺点

consul心跳只是以ping tcp端口为标准, 无法确定服务是否正常响应
当有节点上线或下线时, 需要nginx reload. 有一定风险 (微服务在运行时难免会触发隐藏Bug或者panic, 如果每次都要nginx reload来确保健康的路由,我认为代价太大)

2.Envoy

Envoy 是专为大型现代 SOA（面向服务架构）架构设计的 L7 代理和通信总线。是istio重要组件之一

不好意思 ,没图, 直接贴envoy.yaml出来讲解一下

node:
  id: id_1
  cluster: test_cluster

watchdog:
  miss_timeout: 0.2s
  megamiss_timeout: 1s
  kill_timeout: 0s
  multikill_timeout: 0s

admin:
  access_log_path: /var/log/admin_access.log
  address:
    socket_address: { address: 127.0.0.1, port_value: 10000 }

static_resources:
  listeners:
  - name: listener_0
    address:
      socket_address: { address: 127.0.0.1, port_value: 19000 }
    filter_chains:
    - filters:
      - name: envoy.http_connection_manager
        config:
          stat_prefix: ingress_http
          codec_type: HTTP2
          route_config:
            name: local_route
            virtual_hosts:
            - name: local_service
              domains: ["*"]
              routes:
              - match: { prefix: "/protobuf.User" }
                route: { cluster: xds_cluster }
          http_filters:
          - name: envoy.router
  clusters:
  - name: xds_cluster
    connect_timeout: { seconds: 1 }
    type: STATIC
    lb_policy: ROUND_ROBIN
    http2_protocol_options: {}
    hosts:
    - socket_address: { address: 127.0.0.1, port_value: 18000 }
    - socket_address: { address: 127.0.0.1, port_value: 17000 }
    health_checks:
    - grpc_health_check: {service_name: YourServiceName}
      unhealthy_threshold : 1
      healthy_threshold: 1
      timeout: 0.5s
      interval: 0.5s
      interval_jitter: 0.5s
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这是一个静态的路由配置,带grpc健康检查, 有四个关键点