Hangfire异常致ASP.NET Core应用崩溃，求跳过异常方案

异常信息 #

Unhandled exception. System.AggregateException: One or more hosted services failed to stop. (The operation was canceled.)
 ---> System.OperationCanceledException: The operation was canceled.
   at System.Threading.CancellationToken.ThrowOperationCanceledException()
   at Hangfire.Processing.TaskExtensions.WaitOneAsync(WaitHandle waitHandle, TimeSpan timeout, CancellationToken token)
   at Hangfire.Processing.BackgroundDispatcher.WaitAsync(TimeSpan timeout, CancellationToken cancellationToken)
   at Hangfire.Server.BackgroundProcessingServer.WaitForShutdownAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.Internal.Host.StopAsync(CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at Microsoft.Extensions.Hosting.Internal.Host.StopAsync(CancellationToken cancellationToken)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.WaitForShutdownAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(IHost host, CancellationToken token)
   at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.Run(IHost host)
   at Microsoft.AspNetCore.Builder.WebApplication.Run(String url

环境版本 #

• ASP.NET Core 6.0.3
• Hangfire.Core 1.7.28、Hangfire.AspNetCore 1.7.28

核心代码 #

Startup.cs - ConfigureServices方法 #

services.AddHangfire();
services.AddHangfireServer();

Startup.cs - Configure方法 #

app.UseHangfireDashboard("/hangfire");

当前分析 #

异常抛出点为Microsoft.Extensions.Hosting.Internal.Host.StopAsync，Hangfire作为内部托管服务，停止时抛出OperationCanceledException，最终引发未被捕获的AggregateException，导致应用崩溃。自定义托管服务可通过IHostedService包装类捕获异常，但Hangfire的托管服务由框架自动注册，需要针对性处理方案。

解决方案 #

可以通过替换Hangfire托管服务的注册逻辑，用自定义包装类包裹其IHostedService实现，从而捕获停止时的异常：

1. 保留你已定义的MyHostedServiceWrapper类（可按需调整日志逻辑）
2. 修改ConfigureServices中的Hangfire注册代码，手动注册并包装：

services.AddHangfire();

// 先注册Hangfire的BackgroundProcessingServer，再替换为包装后的服务
services.AddSingleton<BackgroundProcessingServer>();
services.AddSingleton<IHostedService>(sp => 
    new MyHostedServiceWrapper(
        sp.GetRequiredService<ILogger<MyHostedServiceWrapper>>(),
        sp.GetRequiredService<BackgroundProcessingServer>()));

如果需要保留Hangfire的默认配置选项，可调整为：

services.AddHangfire();

// 先添加HangfireServer的自定义配置
services.AddHangfireServer(options => 
{
    // 此处添加你的HangfireServer配置项
});

// 移除默认注册的IHostedService，替换为包装后的版本
var descriptor = services.FirstOrDefault(d => d.ServiceType == typeof(IHostedService) && d.ImplementationType == typeof(BackgroundProcessingServer));
if (descriptor != null)
{
    services.Remove(descriptor);
    services.AddSingleton<IHostedService>(sp => 
        new MyHostedServiceWrapper(
            sp.GetRequiredService<ILogger<MyHostedServiceWrapper>>(),
            ActivatorUtilities.CreateInstance<BackgroundProcessingServer>(sp, descriptor.ImplementationInstance)));
}

通过此方式，Hangfire服务停止时抛出的异常会被包装类捕获并记录日志，不会向上传递导致应用崩溃。另外，也可以尝试升级Hangfire到最新稳定版本，新版本可能已修复停止阶段抛出取消异常的问题。

内容的提问来源于stack exchange，提问作者Arvind Maurya