Files
Academic-Affairs-System/src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobOutboxPublisher.cs
T
2026-08-09 10:13:12 +08:00

341 lines
14 KiB
C#

using System.Diagnostics;
using Jiaowu.Api.Domain.Academic;
using Jiaowu.Api.Domain.System;
using Jiaowu.Api.Infrastructure.Persistence;
using Microsoft.EntityFrameworkCore;
namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
public sealed class BackgroundJobOutboxPublisher(
IServiceScopeFactory scopeFactory,
IBackgroundJobTransport transport,
BackgroundJobOptions options,
BackgroundJobTelemetry telemetry,
ILogger<BackgroundJobOutboxPublisher> logger) : BackgroundService
{
protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
await PrepareForStartupAsync(stoppingToken);
var nextMaintenanceAt = DateTime.MinValue;
while (!stoppingToken.IsCancellationRequested)
{
try
{
if (DateTime.UtcNow >= nextMaintenanceAt)
{
await RecoverExpiredProcessingAsync(stoppingToken);
await CleanupCompletedAsync(stoppingToken);
nextMaintenanceAt = DateTime.UtcNow.AddSeconds(
options.MaintenanceIntervalSeconds);
}
var claimed = await ClaimNextAsync(stoppingToken);
if (claimed is null)
{
await Task.Delay(options.PollIntervalMilliseconds, stoppingToken);
continue;
}
await PublishClaimedAsync(claimed.Value.Message, claimed.Value.Token,
stoppingToken);
}
catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
{
break;
}
catch (Exception exception)
{
logger.LogError(exception, "Background job outbox publishing failed.");
await Task.Delay(TimeSpan.FromSeconds(2), stoppingToken);
}
}
}
private async Task PrepareForStartupAsync(CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
if (!transport.IsDurable)
{
await db.BackgroundJobOutboxMessages
.Where(x => x.State != BackgroundJobOutboxState.Completed)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, BackgroundJobOutboxState.Pending)
.SetProperty(x => x.ProcessingToken, (Guid?)null)
.SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
cancellationToken);
}
await AddMissingOutboxMessagesAsync(db, cancellationToken);
}
private async Task AddMissingOutboxMessagesAsync(
AppDbContext db,
CancellationToken cancellationToken)
{
var automaticJobs = await db.AutomaticScheduleJobs.AsNoTracking()
.Where(x =>
(x.Status == AutomaticScheduleJobStatus.Queued ||
x.Status == AutomaticScheduleJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.AutomaticSchedule &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var publishJobs = await db.SchedulePublishJobs.AsNoTracking()
.Where(x =>
(x.Status == SchedulePublishJobStatus.Queued ||
x.Status == SchedulePublishJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.SchedulePublish &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var makeupJobs = await db.MakeupExamAutoJobs.AsNoTracking()
.Where(x =>
(x.Status == MakeupExamAutoJobStatus.Queued ||
x.Status == MakeupExamAutoJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.MakeupExamAuto &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var arrangementJobs = await db.ExamArrangementJobs.AsNoTracking()
.Where(x =>
(x.Status == ExamArrangementJobStatus.Queued ||
x.Status == ExamArrangementJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.ExamArrangement &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var exportJobs = await db.ExamSignInExportJobs.AsNoTracking()
.Where(x =>
(x.Status == ExamSignInExportJobStatus.Queued ||
x.Status == ExamSignInExportJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.ExamSignInExport &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var publishJobs2 = await db.ExamPublishJobs.AsNoTracking()
.Where(x =>
(x.Status == ExamPublishJobStatus.Queued ||
x.Status == ExamPublishJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.ExamPublish &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var gradeStatisticsJobs = await db.CourseGradeStatisticsRefreshJobs.AsNoTracking()
.Where(x =>
(x.Status == CourseGradeStatisticsRefreshJobStatus.Queued ||
x.Status == CourseGradeStatisticsRefreshJobStatus.Running) &&
!db.BackgroundJobOutboxMessages.Any(message =>
message.JobKind == BackgroundJobKind.CourseGradeStatisticsRefresh &&
message.JobId == x.Id))
.Select(x => x.Id)
.ToListAsync(cancellationToken);
var missingKeys = automaticJobs
.Select(id => (BackgroundJobKind.AutomaticSchedule, id))
.Concat(publishJobs.Select(id =>
(BackgroundJobKind.SchedulePublish, id)))
.Concat(makeupJobs.Select(id =>
(BackgroundJobKind.MakeupExamAuto, id)))
.Concat(arrangementJobs.Select(id =>
(BackgroundJobKind.ExamArrangement, id)))
.Concat(exportJobs.Select(id =>
(BackgroundJobKind.ExamSignInExport, id)))
.Concat(publishJobs2.Select(id =>
(BackgroundJobKind.ExamPublish, id)))
.Concat(gradeStatisticsJobs.Select(id =>
(BackgroundJobKind.CourseGradeStatisticsRefresh, id)))
.ToList();
foreach (var (kind, jobId) in missingKeys)
{
db.BackgroundJobOutboxMessages.Add(
BackgroundJobOutboxMessage.Create(kind, jobId));
}
if (!db.ChangeTracker.HasChanges())
return;
try
{
await db.SaveChangesAsync(cancellationToken);
}
catch (DbUpdateException)
{
db.ChangeTracker.Clear();
foreach (var (kind, jobId) in missingKeys)
{
var recovered = await db.BackgroundJobOutboxMessages
.AsNoTracking()
.AnyAsync(
message => message.JobKind == kind &&
message.JobId == jobId,
cancellationToken);
if (!recovered)
throw;
}
logger.LogInformation(
"Another application instance recovered {Count} missing outbox messages first.",
missingKeys.Count);
}
}
private async Task CleanupCompletedAsync(CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var cutoff = DateTime.UtcNow.AddDays(-options.CompletedRetentionDays);
var completedIds = await db.BackgroundJobOutboxMessages.AsNoTracking()
.Where(x =>
x.State == BackgroundJobOutboxState.Completed &&
x.CompletedAt != null &&
x.CompletedAt < cutoff)
.OrderBy(x => x.CompletedAt)
.Select(x => x.Id)
.Take(options.CleanupBatchSize)
.ToListAsync(cancellationToken);
if (completedIds.Count == 0)
return;
foreach (var id in completedIds)
{
db.BackgroundJobOutboxMessages.Remove(
new BackgroundJobOutboxMessage { Id = id });
}
await db.SaveChangesAsync(cancellationToken);
telemetry.RecordCleaned(completedIds.Count);
logger.LogInformation(
"Removed {Count} completed background job outbox messages older than {Cutoff}.",
completedIds.Count,
cutoff);
}
private async Task RecoverExpiredProcessingAsync(
CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var now = DateTime.UtcNow;
var recoveredState = transport.IsDurable
? BackgroundJobOutboxState.Published
: BackgroundJobOutboxState.Pending;
await db.BackgroundJobOutboxMessages
.Where(x =>
(x.State == BackgroundJobOutboxState.Publishing ||
x.State == BackgroundJobOutboxState.Processing) &&
x.LeaseExpiresAt != null &&
x.LeaseExpiresAt < now)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, recoveredState)
.SetProperty(x => x.ProcessingToken, (Guid?)null)
.SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
cancellationToken);
}
private async Task<(BackgroundJobEnvelope Message, Guid Token)?> ClaimNextAsync(
CancellationToken cancellationToken)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var candidateId = await db.BackgroundJobOutboxMessages.AsNoTracking()
.Where(x => x.State == BackgroundJobOutboxState.Pending)
.OrderBy(x => x.CreatedAt)
.Select(x => (Guid?)x.Id)
.FirstOrDefaultAsync(cancellationToken);
if (!candidateId.HasValue)
return null;
var token = Guid.NewGuid();
var leaseExpiresAt = DateTime.UtcNow.AddSeconds(options.LeaseSeconds);
var claimed = await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == candidateId.Value &&
x.State == BackgroundJobOutboxState.Pending)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, BackgroundJobOutboxState.Publishing)
.SetProperty(x => x.ProcessingToken, token)
.SetProperty(x => x.LeaseExpiresAt, leaseExpiresAt)
.SetProperty(x => x.PublishAttempts, x => x.PublishAttempts + 1)
.SetProperty(x => x.LastError, (string?)null),
cancellationToken);
if (claimed == 0)
return null;
var message = await db.BackgroundJobOutboxMessages.AsNoTracking()
.Where(x => x.Id == candidateId.Value)
.Select(x => new BackgroundJobEnvelope(x.Id, x.JobKind, x.JobId))
.SingleAsync(cancellationToken);
return (message, token);
}
private async Task PublishClaimedAsync(
BackgroundJobEnvelope message,
Guid token,
CancellationToken cancellationToken)
{
var startedAt = Stopwatch.GetTimestamp();
try
{
await transport.PublishAsync(message, cancellationToken);
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == message.OutboxMessageId &&
x.State == BackgroundJobOutboxState.Publishing &&
x.ProcessingToken == token)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, BackgroundJobOutboxState.Published)
.SetProperty(x => x.PublishedAt, DateTime.UtcNow)
.SetProperty(x => x.ProcessingToken, (Guid?)null)
.SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
cancellationToken);
telemetry.RecordPublish(
message.JobKind,
transport.IsDurable,
"published",
Stopwatch.GetElapsedTime(startedAt));
}
catch (Exception exception)
{
await using var scope = scopeFactory.CreateAsyncScope();
var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
var messageText = exception.GetBaseException().Message;
if (messageText.Length > 2000)
messageText = messageText[..2000];
await db.BackgroundJobOutboxMessages
.Where(x =>
x.Id == message.OutboxMessageId &&
x.State == BackgroundJobOutboxState.Publishing &&
x.ProcessingToken == token)
.ExecuteUpdateAsync(
setters => setters
.SetProperty(x => x.State, BackgroundJobOutboxState.Pending)
.SetProperty(x => x.ProcessingToken, (Guid?)null)
.SetProperty(x => x.LeaseExpiresAt, (DateTime?)null)
.SetProperty(x => x.LastError, messageText),
cancellationToken);
telemetry.RecordPublish(
message.JobKind,
transport.IsDurable,
"failed",
Stopwatch.GetElapsedTime(startedAt));
throw;
}
}
}