Csharp 利用.NET 8中的AddStandardResilienceDeliveries和AddStandardHedgingDeliveries实现Resiliency

我有一个.NET 8 API，使用Polly来恢复Azure SQL和Microsoft Curve等外部服务的弹性.我当前的实现使用自定义再试和断路器策略，如下所示:

PollyExtensions.cs:

public static class PollyExtensions
{
    public static AsyncRetryPolicy CreateRetryPolicy(this ILogger logger, string infraService)
    {
        var delay = Backoff.DecorrelatedJitterBackoffV2(medianFirstRetryDelay: TimeSpan.FromSeconds(1), retryCount: 5);

        return Policy
            .Handle<SqlException>()
            .Or<Exception>()
            .Or<TimeoutException>()
            .WaitAndRetryAsync(delay,
                onRetry: (exception, timespan, retryAttempt, context) =>
                {
                    logger.LogWarning(exception, "Error talking to {infraService}, Error: {Message}, will retry after {timeSpan}. Retry attempt {retryCount} ",
                        infraService, exception.Message, timespan, retryAttempt);
                });
    }

    public static AsyncCircuitBreakerPolicy CreateCircuitBreakerPolicy()
    {
        return Policy
            .Handle<Exception>()
            .CircuitBreakerAsync(
                exceptionsAllowedBeforeBreaking: 5,
                durationOfBreak: TimeSpan.FromMinutes(1)
            );
    }
}

在探索.NET 8中的新功能时，我发现了实现弹性的AddStandardResilienceHandler和AddStandardHedgingHandler.

References :

https://devblogs.microsoft.com/dotnet/building-resilient-cloud-services-with-dotnet-8/

https://juliocasal.com/blog/Building-Microservices-With-Dotnet-8

有人可以提供代码示例来演示如何在我的GraphSvcClient类的上下文中使用AddStandardResilienceeds和AddStandardHedgingeeds来进行外部依赖项调用？

与自定义策略相比，使用这些新功能时是否有任何具体的注意事项？

GraphSvcClient.cs

public sealed class GraphSvcClient(ICacheProvider cacheProvider,
    IAzureAuthTokenService azureAuthTokenService,    
    ILogger<GraphSvcClient> logger) : IGraphSvcClient
{
    private readonly ICacheProvider _cacheProvider = cacheProvider.IsNotNull();
    private readonly IAzureAuthTokenService _azureAuthTokenService = azureAuthTokenService.IsNotNull();
    private readonly ILogger<GraphSvcClient> _logger = logger.IsNotNull();
    
    /// <summary>
    /// Get Microsoft Graph graphClient
    /// </summary>
    /// <returns></returns>
    public async Task<GraphServiceClient> GetGraphServiceClientAsync()
    {
        var accessToken = await GetAccessTokenAsync();

        var retryPolicy = _logger.CreateRetryPolicy(infraService: "MicrosoftGraph");
        var circuitBreakerPolicy = PollyExtensions.CreateCircuitBreakerPolicy();

        var combinedPolicy = Policy.WrapAsync(retryPolicy, circuitBreakerPolicy);

        var graphServiceClient = await combinedPolicy.ExecuteAsync(async () =>
        {
            var client = new GraphServiceClient(new DelegateAuthenticationProvider(async (req) =>
            {
                req.Headers.Authorization = new AuthenticationHeaderValue(JwtBearerDefaults.AuthenticationScheme, accessToken);
                await Task.CompletedTask;
            }));
            return client;
        });

        return graphServiceClient;
    }
}

我正在考虑将Polly及其相关的nuget包更新到最新的兼容版本，以利用.NET 8中的最新功能.

项目中使用的Nuget包列表:

<PackageReference Include="Polly" Version="7.2.4" />
<PackageReference Include="Polly.Contrib.WaitAndRetry" Version="1.1.1" />
<PackageReference Include="Microsoft.Extensions.Http.Polly" Version="8.0.0" />