Files
Academic-Affairs-System/src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobRunner.cs
T
biss 034f1eacb8 第二阶段优化已完成,重点是提高后台任务吞吐并降低 Outbox 数据库开销。
RabbitMQ 默认从单一回调通道提升为三类任务独立并行,跨类型并发能力由 1 提升到 3;每类还能独立配置 1–16 个消费者。[RabbitMqBackgroundJobs.cs (line 143)](E:/jiaowu/src/Jiaowu.Api/Infrastructure/BackgroundJobs/RabbitMqBackgroundJobs.cs:143)
InMemory 开发模式同步改为按任务类型隔离队列,避免某类长任务堵塞其他任务。
租约恢复检查从“每发布一条执行一次”改为默认每 60 秒维护一次。
启动恢复改为数据库 NOT EXISTS 查询,不再把全部历史 Outbox 加载进内存。[BackgroundJobOutboxPublisher.cs (line 9)](E:/jiaowu/src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobOutboxPublisher.cs:9)
完成消息默认保留 14 天,之后按每批 500 条清理,并增加对应组合索引。
/health/messaging 现在返回各状态积压量、过期租约和最老任务等待时间。[BackgroundJobMonitoringService.cs (line 16)](E:/jiaowu/src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobMonitoringService.cs:16)
新增 Jiaowu.BackgroundJobs 运行时指标,覆盖发布量、处理量、发布耗时、处理耗时和清理量。[BackgroundJobTelemetry.cs (line 9)](E:/jiaowu/src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobTelemetry.cs:9)
配置、Compose 和调优建议已更新。[README.md (line 257)](E:/jiaowu/README.md:257)
2026-07-26 21:05:18 +08:00

349 lines
14 KiB
C#

using System.Diagnostics;
using Jiaowu.Api.Domain.Academic;
using Jiaowu.Api.Domain.System;
using Jiaowu.Api.Infrastructure.Exams;
using Jiaowu.Api.Infrastructure.Persistence;
using Jiaowu.Api.Infrastructure.Scheduling;
using Microsoft.EntityFrameworkCore;
namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
public sealed record BackgroundJobRunResult(
BackgroundJobRunOutcome Outcome,
TimeSpan RetryAfter)
{
public static BackgroundJobRunResult Completed { get; } =
new(BackgroundJobRunOutcome.Completed, TimeSpan.Zero);
public static BackgroundJobRunResult Retry(TimeSpan retryAfter) =>
new(BackgroundJobRunOutcome.Retry, retryAfter);
}
public enum BackgroundJobRunOutcome
{
Completed,
Retry
}
public sealed class BackgroundJobRunner(
IServiceScopeFactory scopeFactory,
IBackgroundJobTransport transport,
BackgroundJobOptions options,
BackgroundJobTelemetry telemetry,
ILogger<BackgroundJobRunner> logger)
{
public async Task<BackgroundJobRunResult> RunAsync(
BackgroundJobEnvelope message,
CancellationToken cancellationToken)
{
var startedAt = Stopwatch.GetTimestamp();
var token = Guid.NewGuid();
var claim = await TryClaimAsync(message, token, cancellationToken);
if (!claim.Claimed)
{
return claim.Completed
? BackgroundJobRunResult.Completed
: BackgroundJobRunResult.Retry(claim.RetryAfter);
}
if (claim.AttemptsExceeded)
{
await MarkJobRetryLimitExceededAsync(message, cancellationToken);
await MarkCompletedAsync(message.OutboxMessageId, token,
cancellationToken);
telemetry.RecordProcessing(
message.JobKind,
"retry-limit",
Stopwatch.GetElapsedTime(startedAt));
return BackgroundJobRunResult.Completed;
}
using var heartbeatCancellation =
CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
var heartbeat = RunHeartbeatAsync(
message.OutboxMessageId,
token,
heartbeatCancellation.Token);
try
{
await using var scope = scopeFactory.CreateAsyncScope();
switch (message.JobKind)
{
case BackgroundJobKind.AutomaticSchedule:
await scope.ServiceProvider
.GetRequiredService<AutomaticScheduleJobProcessor>()
.ProcessAsync(message.JobId, cancellationToken);
break;
case BackgroundJobKind.SchedulePublish:
await scope.ServiceProvider
.GetRequiredService<SchedulePublishJobProcessor>()
.ProcessAsync(message.JobId, cancellationToken);
break;
case BackgroundJobKind.MakeupExamAuto:
await scope.ServiceProvider
.GetRequiredService<MakeupExamAutoJobProcessor>()
.ProcessAsync(message.JobId, cancellationToken);
break;
default:
throw new InvalidOperationException(
$"Unsupported background job kind '{message.JobKind}'.");
}
await MarkCompletedAsync(message.OutboxMessageId, token,
cancellationToken);
telemetry.RecordProcessing(
message.JobKind,
"completed",
Stopwatch.GetElapsedTime(startedAt));
return BackgroundJobRunResult.Completed;
}
catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
{
throw;
}
catch (Exception exception)
{
logger.LogError(
exception,
"Background job {JobKind}/{JobId} will be retried.",
message.JobKind,
message.JobId);
await ReleaseForRetryAsync(
message.OutboxMessageId,
token,
exception,
CancellationToken.None);
telemetry.RecordProcessing(
message.JobKind,
"retry",
Stopwatch.GetElapsedTime(startedAt));
return BackgroundJobRunResult.Retry(TimeSpan.FromSeconds(2));
}
finally
{
await heartbeatCancellation.CancelAsync();
try
{
await heartbeat;
}
catch (OperationCanceledException)
{
// Expected when processing completes or the application stops.
}
}
}
private async Task<(
bool Claimed,
bool Completed,
bool AttemptsExceeded,
TimeSpan RetryAfter)>
TryClaimAsync(
BackgroundJobEnvelope message,
Guid token,
CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var now = DateTime.UtcNow;
var leaseExpiresAt = now.AddSeconds(options.LeaseSeconds);
var claimed = await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == message.OutboxMessageId &&
x.JobKind == message.JobKind &&
x.JobId == message.JobId &&
(x.State == BackgroundJobOutboxState.Pending ||
x.State == BackgroundJobOutboxState.Publishing ||
x.State == BackgroundJobOutboxState.Published ||
(x.State == BackgroundJobOutboxState.Processing &&
x.LeaseExpiresAt != null &&
x.LeaseExpiresAt < now)))
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, BackgroundJobOutboxState.Processing)
.SetProperty(x => x.ProcessingToken, token)
.SetProperty(x => x.LeaseExpiresAt, leaseExpiresAt)
.SetProperty(
x => x.ProcessingAttempts,
x => x.ProcessingAttempts + 1)
.SetProperty(x => x.LastError, (string?)null),
cancellationToken);
if (claimed == 1)
{
var attempts = await db.BackgroundJobOutboxMessages.AsNoTracking()
.Where(x => x.Id == message.OutboxMessageId)
.Select(x => x.ProcessingAttempts)
.SingleAsync(cancellationToken);
return (
true,
false,
attempts > options.ProcessingAttemptLimit,
TimeSpan.Zero);
}
var current = await db.BackgroundJobOutboxMessages.AsNoTracking()
.Where(x => x.Id == message.OutboxMessageId)
.Select(x => new { x.State, x.LeaseExpiresAt })
.FirstOrDefaultAsync(cancellationToken);
if (current is null || current.State == BackgroundJobOutboxState.Completed)
return (false, true, false, TimeSpan.Zero);
var retryAfter = current.LeaseExpiresAt.HasValue
? current.LeaseExpiresAt.Value - now
: TimeSpan.FromSeconds(2);
retryAfter = TimeSpan.FromSeconds(Math.Clamp(
retryAfter.TotalSeconds,
1,
options.LeaseSeconds));
return (false, false, false, retryAfter);
}
private async Task MarkJobRetryLimitExceededAsync(
BackgroundJobEnvelope message,
CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var completedAt = DateTime.UtcNow;
var error = $"后台任务连续处理失败超过 {options.ProcessingAttemptLimit} 次," +
"已停止自动重试,请检查服务日志后重新创建任务。";
switch (message.JobKind)
{
case BackgroundJobKind.AutomaticSchedule:
await db.AutomaticScheduleJobs
.Where(x =>
x.Id == message.JobId &&
x.Status != AutomaticScheduleJobStatus.Succeeded &&
x.Status != AutomaticScheduleJobStatus.Failed)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(
x => x.Status,
AutomaticScheduleJobStatus.Failed)
.SetProperty(x => x.ActiveSchedulePlanId, (Guid?)null)
.SetProperty(x => x.ErrorMessage, error)
.SetProperty(x => x.CompletedAt, completedAt),
cancellationToken);
break;
case BackgroundJobKind.SchedulePublish:
await db.SchedulePublishJobs
.Where(x =>
x.Id == message.JobId &&
x.Status != SchedulePublishJobStatus.Succeeded &&
x.Status != SchedulePublishJobStatus.Failed)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(
x => x.Status,
SchedulePublishJobStatus.Failed)
.SetProperty(x => x.ActiveAcademicTermId, (Guid?)null)
.SetProperty(x => x.CurrentStep, "后台处理已停止")
.SetProperty(x => x.ErrorMessage, error)
.SetProperty(x => x.CompletedAt, completedAt),
cancellationToken);
break;
case BackgroundJobKind.MakeupExamAuto:
await db.MakeupExamAutoJobs
.Where(x =>
x.Id == message.JobId &&
x.Status != MakeupExamAutoJobStatus.Succeeded &&
x.Status != MakeupExamAutoJobStatus.Failed)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(
x => x.Status,
MakeupExamAutoJobStatus.Failed)
.SetProperty(x => x.ErrorMessage, error)
.SetProperty(x => x.CompletedAt, completedAt),
cancellationToken);
break;
default:
throw new ArgumentOutOfRangeException(
nameof(message.JobKind),
message.JobKind,
null);
}
logger.LogError(
"Background job {JobKind}/{JobId} exceeded {AttemptLimit} processing attempts.",
message.JobKind,
message.JobId,
options.ProcessingAttemptLimit);
}
private async Task RunHeartbeatAsync(
Guid outboxMessageId,
Guid token,
CancellationToken cancellationToken)
{
var intervalSeconds = Math.Max(5, options.LeaseSeconds / 3);
while (!cancellationToken.IsCancellationRequested)
{
await Task.Delay(TimeSpan.FromSeconds(intervalSeconds), cancellationToken);
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == outboxMessageId &&
x.State == BackgroundJobOutboxState.Processing &&
x.ProcessingToken == token)
.ExecuteUpdateAsync(
setters => setters.SetProperty(
x => x.LeaseExpiresAt,
DateTime.UtcNow.AddSeconds(options.LeaseSeconds)),
cancellationToken);
}
}
private async Task MarkCompletedAsync(
Guid outboxMessageId,
Guid token,
CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == outboxMessageId &&
x.State == BackgroundJobOutboxState.Processing &&
x.ProcessingToken == token)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, BackgroundJobOutboxState.Completed)
.SetProperty(x => x.CompletedAt, DateTime.UtcNow)
.SetProperty(x => x.ProcessingToken, (Guid?)null)
.SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
cancellationToken);
}
private async Task ReleaseForRetryAsync(
Guid outboxMessageId,
Guid token,
Exception exception,
CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var message = exception.GetBaseException().Message;
if (message.Length > 2000)
message = message[..2000];
var state = transport.IsDurable
? BackgroundJobOutboxState.Published
: BackgroundJobOutboxState.Pending;
await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == outboxMessageId &&
x.State == BackgroundJobOutboxState.Processing &&
x.ProcessingToken == token)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, state)
.SetProperty(x => x.ProcessingToken, (Guid?)null)
.SetProperty(x => x.LeaseExpiresAt, (DateTime?)null)
.SetProperty(x => x.LastError, message),
cancellationToken);
}
}