.NET 7健康检查重复执行：如何实现单次执行兼顾存储与通知

问题分析 #

当前配置存在两个独立的定时触发逻辑，导致健康检查重复执行且功能割裂：

• HealthCheckPublisherOptions.Period：.NET内置的健康检查定时任务，会重复执行检查并调用CustomHealthCheckPublisher.PublishAsync，但不会将结果持久化到PostgreSQL
• HealthChecksUI.SetEvaluationTimeInSeconds：HealthChecksUI的定时任务，会调用健康检查端点并将结果存入数据库，但不会触发自定义邮件通知

解决方案 #

核心思路是禁用.NET内置的健康检查定时任务，完全依托HealthChecksUI的定时机制执行检查并持久化结果，同时在UI执行完检查后触发自定义邮件通知逻辑。

具体步骤 #

1. 移除内置定时配置：删除HealthCheckPublisherOptions的Period设置，避免内置定时触发重复检查
2. 绑定UI执行回调：在HealthChecksUI的配置中添加OnHealthCheckExecuted回调，每次UI完成检查并持久化结果后，调用CustomHealthCheckPublisher.PublishAsync发送故障邮件

修改后的代码 #

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services
        .AddHealthChecks()
        .AddCheck<NotificationsServiceHealthCheck>("Notifications service health check", tags: new[] { "external-service" });

    // 移除内置健康检查定时配置，避免重复执行
    // services.Configure<HealthCheckPublisherOptions>(options =>
    // {
    //     options.Period = TimeSpan.FromSeconds(evaluationTimeInSeconds);
    // });

    services.AddSingleton<IHealthCheckPublisher, CustomHealthCheckPublisher>();

    var evaluationTimeInSeconds = 60;
    services
        .AddHealthChecksUI(setup =>
        {
            setup.AddHealthCheckEndpoint("External services health checks", "https://localhost:44366/health-external-services");
            setup.SetEvaluationTimeInSeconds(evaluationTimeInSeconds);
            // 添加UI执行完成后的回调，触发邮件通知
            setup.OnHealthCheckExecuted(async (context) =>
            {
                var publisher = context.ServiceProvider.GetRequiredService<CustomHealthCheckPublisher>();
                await publisher.PublishAsync(context.Report, context.CancellationToken);
            });
        })
        .AddPostgreSqlStorage("CONNECTION_STRING", c => c.UseNpgsql(o => o.MigrationsHistoryTable(HistoryRepository.DefaultTableName, "hangfire")));
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILogger<Startup> logger)
{
    app.UseEndpoints(endpoints =>
    {
        endpoints.MapHealthChecks("/health-external-services", new HealthCheckOptions()
        {
            Predicate = r => r.Tags.Contains("external-service"),
            ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
        });
        
        endpoints.MapHealthChecksUI(setup =>
        {
            setup.UIPath = "/HealthChecks";
            setup.AsideMenuOpened = false;
        });
    });
}

CustomHealthCheckPublisher.cs（无需修改）

public class CustomHealthCheckPublisher : IHealthCheckPublisher
{
    public Task PublishAsync(HealthReport report, CancellationToken cancellationToken)
    {
        if (report.Status == HealthStatus.Healthy)
        {
            return Task.CompletedTask;
        }

        var nonhealthyChecks = report.Entries
            .Where(x => x.Value.Status != HealthStatus.Healthy)
            .ToList();

        // 发送包含nonhealthyChecks的故障邮件

        return Task.CompletedTask;
    }
}

效果说明 #

• 健康检查仅由HealthChecksUI的定时任务触发，每60秒执行一次
• 检查结果自动持久化到PostgreSQL
• 每次检查完成后，自动调用CustomHealthCheckPublisher.PublishAsync，仅当检查状态为非健康时发送邮件通知

内容的提问来源于stack exchange，提问作者Aleks Vujic