(更新时间)2021年5月28日 商城高并发秒杀系统(.NET Core版) 05-断路器Polly组件的封装

一：断路器Polly组件的封装

/// <summary>
/// HttpClient熔断降级策略选项
/// </summary>
public class PollyHttpClientOptions
{
    //1、设置默认值
    public PollyHttpClientOptions()
    {
        this.TimeoutTime = 60;
        this.RetryCount = 3;
        this.CircuitBreakerOpenFallCount = 2;
        this.CircuitBreakerOpenFallCount = 5;
        this.ResponseMessage = "服务熔断降级了~~~";
    }

    /// <summary>
    /// 超时时间设置，单位为秒
    /// </summary>
    public int TimeoutTime { set; get; }

    /// <summary>
    /// 失败重试次数
    /// </summary>
    public int RetryCount { set; get; }

    /// <summary>
    /// 执行多少次异常，开启短路器（例：失败2次，开启断路器）
    /// </summary>
    public int CircuitBreakerOpenFallCount { set; get; }

    /// <summary>
    /// 断路器开启的时间(例如：设置为2秒，短路器两秒后自动由开启到关闭)
    /// </summary>
    public int CircuitBreakerDownTime { set; get; }

    /// <summary>
    /// 降级处理(将异常消息封装成为正常消息返回，然后进行响应处理，例如：系统正在繁忙，请稍后处理.....)
    /// </summary>
    public string ResponseMessage { set; get; }
}

  

 

  
1
  
2
  
3
  
4
  
5
  
6
  
7
  
8
  
9
  
10
  
11
  
12
  
13
  
14
  
15
  
16
  
17
  
18
  
19
  
20
  
21
  
22
  
23
  
24
  
25
  
26
  
27
  
28
  
29
  
30
  
31
  
32
  
33
  
34
  
35
  
36
  
37
  
38
  
39
  
40
 

二：配置选项

/// <summary>
/// 微服务中HttpClient熔断，降级策略扩展
/// </summary>
public static class PollyHttpClientServiceCollectionExtensions
{

    /// <summary>
    /// Httpclient扩展方法
    /// </summary>
    /// <param name="services">ioc容器</param>
    /// <param name="name">HttpClient 名称(针对不同的服务进行熔断，降级)</param>
    /// <param name="action">熔断降级配置</param>
    /// <param name="TResult">降级处理错误的结果</param>
    /// <returns></returns>
    public static IServiceCollection AddPollyHttpClient(this IServiceCollection services, string name, Action<PollyHttpClientOptions> action)
    {
        // 1、创建选项配置类
        PollyHttpClientOptions options = new PollyHttpClientOptions();
        action(options);

        // 2、封装降级消息
        var fallbackResponse = new HttpResponseMessage
        {
            Content = new StringContent(options.ResponseMessage), // 降级消息
            StatusCode = HttpStatusCode.GatewayTimeout // 降级状态码
        };

        // 2、配置httpClient,熔断降级策略
        services.AddHttpClient(name)
       
       //1.1 降级策略
       .AddPolicyHandler(Policy<HttpResponseMessage>.HandleInner<Exception>().FallbackAsync(fallbackResponse, async b =>
       {
           // 1、降级打印异常
           Console.WriteLine($"服务{name}开始降级,异常消息：{b.Exception.Message}");
           // 2、降级后的数据
           Console.WriteLine($"服务{name}降级内容响应：{fallbackResponse.RequestMessage}");
           await Task.CompletedTask;
       }))
        // 1.2 断路器策略
        .AddPolicyHandler(Policy<HttpResponseMessage>.Handle<Exception>().CircuitBreakerAsync(options.CircuitBreakerOpenFallCount, TimeSpan.FromSeconds(options.CircuitBreakerDownTime), (ex, ts) =>
        {
            Console.WriteLine($"服务{name}断路器开启，异常消息：{ex.Exception.Message}");
            Console.WriteLine($"服务{name}断路器开启时间：{ts.TotalSeconds}s");
        }, () =>
        {
            Console.WriteLine($"服务{name}断路器关闭");
        }, () =>
        {
            Console.WriteLine($"服务{name}断路器半开启(时间控制，自动开关)");
        }))
        // 1.3 重试策略
        .AddPolicyHandler(Policy<HttpResponseMessage>
          .Handle<Exception>()
          .RetryAsync(options.RetryCount)
        )
        // 1.4 超时策略
        .AddPolicyHandler(Policy.TimeoutAsync<HttpResponseMessage>(TimeSpan.FromSeconds(options.TimeoutTime)));
        return services;
    }


}

  

 

  
1
  
2
  
3
  
4
  
5
  
6
  
7
  
8
  
9
  
10
  
11
  
12
  
13
  
14
  
15
  
16
  
17
  
18
  
19
  
20
  
21
  
22
  
23
  
24
  
25
  
26
  
27
  
28
  
29
  
30
  
31
  
32
  
33
  
34
  
35
  
36
  
37
  
38
  
39
  
40
  
41
  
42
  
43
  
44
  
45
  
46
  
47
  
48
  
49
  
50
  
51
  
52
  
53
  
54
  
55
  
56
  
57
  
58
  
59
  
60
  
61
  
62
  
63
 

文章来源: codeboy.blog.csdn.net，作者：愚公搬代码，版权归原作者所有，如需转载，请联系作者。

原文链接：codeboy.blog.csdn.net/article/details/117375763