【微服务部署】03-健康检查

文章目录

• • [1. 探针集成实现高可用](#1. 探针集成实现高可用)
  • • [1.1 LivenessProbe](#1.1 LivenessProbe)
    • [1.2 ReadinessProbe](#1.2 ReadinessProbe)
    • [1.3 StartupProbe](#1.3 StartupProbe)
  • [2. 健康检查看板](#2. 健康检查看板)
  • • [2.1 组件包](#2.1 组件包)

1. 探针集成实现高可用

• Liveness
• Readiness
• Startup

1.1 LivenessProbe

• 判断服务是否存活
• 结束"非存活"状态服务
• 根据重启策略决定是否重启服务

1.2 ReadinessProbe

• 判断服务是否"就绪"
• "就绪"状态的服务可以接收请求
• 非"就绪"状态的服务将会被从流量负载中摘除

1.3 StartupProbe

• 检测应用程序是否启动成功

• 启动探针执行成功后，将不再执行，除非应用重启

• 当启动探针检测成功后，其它探针才开始工作

• 适合启动较慢的应用配置

• Kuberbetes 1.16以后的支持

  // startup
  internal static bool Ready { get; set; } = true;
  internal static bool Live { get; set; } = true;

  public void ConfigureServices(IServiceCollection services)
  {
  ...
  // 注册健康检查
  services.AddHealthChecks()
  .AddMySql(Configuration.GetValue<string>("Mysql"), "mysql", tags: new string[] { "mysql", "live", "all" })// tags标签分组
  .AddRabbitMQ(s =>
  {
  var connectionFactory = new RabbitMQ.Client.ConnectionFactory();
  Configuration.GetSection("RabbitMQ").Bind(connectionFactory);
  return connectionFactory;
  }, "rabbitmq", tags: new string[] { "rabbitmq", "live", "all" })
  .AddCheck("liveChecker", () =>
  {
  return Live ? HealthCheckResult.Healthy() : HealthCheckResult.Unhealthy();
  }, new string[] { "live", "all" })
  .AddCheck("readyChecker", () =>
  {
  return Ready ? HealthCheckResult.Healthy() : HealthCheckResult.Unhealthy();
  }, new string[] { "ready", "all" });
  }

  //
  public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
  {
  ...
  app.UseEndpoints(endpoints =>
  {
  endpoints.MapMetrics();
  endpoints.MapHealthChecks("/live", new HealthCheckOptions { Predicate = registration => registration.Tags.Contains("live") });// 检查标记了live的检查项
  endpoints.MapHealthChecks("/ready", new HealthCheckOptions { Predicate = registration => registration.Tags.Contains("ready") });
  endpoints.MapHealthChecks("/hc", new Microsoft.AspNetCore.Diagnostics.HealthChecks.HealthCheckOptions
  {
  ResponseWriter = HealthChecks.UI.Client.UIResponseWriter.WriteHealthCheckUIResponse
  });// 没有传检查项，检查所有
  endpoints.MapControllers();
  endpoints.MapGrpcService<GeekTime.Ordering.API.Grpc.OrderServiceImpl>();
  });
  }

  // Controller调用
  // 设置Ready的值
  [HttpGet]
  public IActionResult SetReady([FromQuery]bool ready)
  {
  Startup.Ready = ready;
  if (!ready)
  {
  Task.Run(async () =>
  {
  await Task.Delay(60000);
  Startup.Ready = true;
  });
  }
  return Content($"{Environment.MachineName} : Ready={Startup.Ready}");
  }

  // 设置live
  [HttpGet]
  public IActionResult SetLive([FromQuery]bool live)
  {
  Startup.Live = live;
  return Content($"{Environment.MachineName} : Live={Startup.Live}");
  }

  // 程序退出
  [HttpGet]
  public IActionResult Exit([FromServices]IHostApplicationLifetime application)
  {
  Task.Run(async () =>
  {
  await Task.Delay(3000);
  application.StopApplication();
  });
  return Content($"{Environment.MachineName} : Stopping");
  }

2. 健康检查看板

AspNetCore.Diagnostics.HealthCheck项目，开源社区项目插件

2.1 组件包

• 探针检测端：AspNetCore.HealthChecks.UI

• 应用端输出：AspNetCore.HealthChecks.UI.Client

• 应用端检查项：AspNetCore.HealthChecks.Xxx

  // startup
  public void ConfigureServices(IServiceCollection services)
  {
  services.AddMvc();
  services.AddHealthChecks();
  services.AddHealthChecksUI();
  }

  public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
  {
  if (env.IsDevelopment())
  {
  app.UseDeveloperExceptionPage();
  }

       app.UseRouting();
       app.UseEndpoints(endpoints =>
       {
           endpoints.MapHealthChecks("/live");
           endpoints.MapHealthChecks("/ready");
           endpoints.MapHealthChecks("/hc");
           endpoints.MapMetrics();
           endpoints.MapHealthChecksUI();// 使得dashboard生效
           endpoints.MapControllers();
       });
   }
  

  // 配置文件配置需要检查的项目
  "HealthChecksUI": {
  "HealthChecks": [
  {
  "Name": "geektime-ordering-api",
  "Uri": "http://geektime-ordering-api/hc"
  },
  {
  "Name": "geektime-mobile-apiaggregator",
  "Uri": "http://geektime-mobile-apiaggregator/hc"
  },
  {
  "Name": "geektime-mobile-gateway",
  "Uri": "http://geektime-mobile-gateway/hc"
  }
  ],