Background Job Generator (Quartz)

Overview

Quartz.NET is a full-featured job scheduling library:

• Job scheduling - Run tasks at specific times or intervals
• Cron expressions - Complex scheduling patterns
• Persistence - Jobs survive application restarts
• Dependency injection - Full DI support
• Clustering - Distributed job execution

Quick Reference

Job Structure

/Infrastructure/
├── BackgroundJobs/
│   ├── {JobName}Job.cs
│   ├── {JobName}JobSetup.cs
│   └── ...
└── DependencyInjection.cs

Template: Simple Interval Job

// src/{name}.infrastructure/BackgroundJobs/ProcessPendingOrdersJob.cs
using Microsoft.Extensions.Logging;
using Quartz;

namespace {name}.infrastructure.backgroundjobs;

/// <summary>
/// Processes pending orders every 5 minutes
/// </summary>
[DisallowConcurrentExecution]  // Prevent overlapping executions
public sealed class ProcessPendingOrdersJob : IJob
{
    private readonly IOrderRepository _orderRepository;
    private readonly IOrderProcessor _orderProcessor;
    private readonly ILogger<ProcessPendingOrdersJob> _logger;

    public ProcessPendingOrdersJob(
        IOrderRepository orderRepository,
        IOrderProcessor orderProcessor,
        ILogger<ProcessPendingOrdersJob> logger)
    {
        _orderRepository = orderRepository;
        _orderProcessor = orderProcessor;
        _logger = logger;
    }

    public async Task Execute(IJobExecutionContext context)
    {
        _logger.LogInformation("Starting pending orders processing...");

        try
        {
            var pendingOrders = await _orderRepository
                .GetPendingOrdersAsync(context.CancellationToken);

            _logger.LogInformation(
                "Found {Count} pending orders to process",
                pendingOrders.Count);

            foreach (var order in pendingOrders)
            {
                try
                {
                    await _orderProcessor.ProcessAsync(order, context.CancellationToken);
                    
                    _logger.LogInformation(
                        "Processed order {OrderId}",
                        order.Id);
                }
                catch (Exception ex)
                {
                    _logger.LogError(
                        ex,
                        "Failed to process order {OrderId}",
                        order.Id);
                }
            }

            _logger.LogInformation("Completed pending orders processing");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error in pending orders processing job");
            throw;  // Quartz will handle retry based on configuration
        }
    }
}

Template: Job Setup (IConfigureOptions)

// src/{name}.infrastructure/BackgroundJobs/ProcessPendingOrdersJobSetup.cs
using Microsoft.Extensions.Options;
using Quartz;

namespace {name}.infrastructure.backgroundjobs;

internal sealed class ProcessPendingOrdersJobSetup 
    : IConfigureOptions<QuartzOptions>
{
    public void Configure(QuartzOptions options)
    {
        var jobKey = JobKey.Create(nameof(ProcessPendingOrdersJob));

        options
            .AddJob<ProcessPendingOrdersJob>(jobBuilder =>
                jobBuilder
                    .WithIdentity(jobKey)
                    .WithDescription("Processes pending orders"))
            .AddTrigger(triggerBuilder =>
                triggerBuilder
                    .ForJob(jobKey)
                    .WithIdentity($"{nameof(ProcessPendingOrdersJob)}-trigger")
                    .WithSimpleSchedule(schedule =>
                        schedule
                            .WithIntervalInMinutes(5)
                            .RepeatForever())
                    .StartNow());
    }
}

Template: Cron Scheduled Job

// src/{name}.infrastructure/BackgroundJobs/DailyReportJob.cs
using Microsoft.Extensions.Logging;
using Quartz;

namespace {name}.infrastructure.backgroundjobs;

/// <summary>
/// Generates daily reports at 6:00 AM every day
/// </summary>
[DisallowConcurrentExecution]
public sealed class DailyReportJob : IJob
{
    private readonly IReportService _reportService;
    private readonly IEmailService _emailService;
    private readonly ILogger<DailyReportJob> _logger;

    public DailyReportJob(
        IReportService reportService,
        IEmailService emailService,
        ILogger<DailyReportJob> logger)
    {
        _reportService = reportService;
        _emailService = emailService;
        _logger = logger;
    }

    public async Task Execute(IJobExecutionContext context)
    {
        _logger.LogInformation("Starting daily report generation...");

        var reportDate = DateTime.UtcNow.Date.AddDays(-1);

        var report = await _reportService.GenerateDailyReportAsync(
            reportDate,
            context.CancellationToken);

        await _emailService.SendReportAsync(
            report,
            context.CancellationToken);

        _logger.LogInformation(
            "Daily report for {Date} sent successfully",
            reportDate.ToShortDateString());
    }
}

// src/{name}.infrastructure/BackgroundJobs/DailyReportJobSetup.cs
using Microsoft.Extensions.Options;
using Quartz;

namespace {name}.infrastructure.backgroundjobs;

internal sealed class DailyReportJobSetup : IConfigureOptions<QuartzOptions>
{
    public void Configure(QuartzOptions options)
    {
        var jobKey = JobKey.Create(nameof(DailyReportJob));

        options
            .AddJob<DailyReportJob>(jobBuilder =>
                jobBuilder
                    .WithIdentity(jobKey)
                    .WithDescription("Daily report generation"))
            .AddTrigger(triggerBuilder =>
                triggerBuilder
                    .ForJob(jobKey)
                    .WithIdentity($"{nameof(DailyReportJob)}-trigger")
                    .WithCronSchedule(
                        "0 0 6 * * ?",  // 6:00 AM every day
                        builder => builder.InTimeZone(TimeZoneInfo.Utc))
                    .WithDescription("Fires at 6:00 AM UTC daily"));
    }
}

Cron Expression Reference

Format: seconds minutes hours day-of-month month day-of-week [year]

Special Characters:

• * - All values
• ? - No specific value (day-of-month/day-of-week)
• - - Range (e.g., MON-FRI)
• , - List (e.g., MON,WED,FRI)
• / - Increment (e.g., 0/15 = every 15)
• L - Last (e.g., last day of month)
• W - Nearest weekday
• # - Nth day (e.g., 2#3 = third Monday)

Template: Job with Data Map

// src/{name}.infrastructure/BackgroundJobs/SendScheduledEmailJob.cs
using Microsoft.Extensions.Logging;
using Quartz;

namespace {name}.infrastructure.backgroundjobs;

/// <summary>
/// Sends a scheduled email using data from JobDataMap
/// </summary>
public sealed class SendScheduledEmailJob : IJob
{
    public const string EmailIdKey = "EmailId";
    public const string