Installation 📦

dotnet add package Shaunebu.Common.Scheduler

Quick Start 🚀

1. Basic Setup

// In MauiProgram.cs or Startup
builder.Services.AddShaunebuScheduler(options =>
{
    options.MaxConcurrentJobs = 5;
    options.ShutdownTimeout = TimeSpan.FromSeconds(30);
    options.ContinueOnFailure = true;
})
.AddConsole()
.AddSchedulerPlugins();

2. Simple Job Scheduling

public class WeatherService
{
    private readonly IScheduler _scheduler;

    public WeatherService(IScheduler scheduler)
    {
        _scheduler = scheduler;
        
        // Schedule weather data refresh every 30 minutes
        _scheduler.ScheduleJob("WeatherRefresh", async (ct) =>
        {
            await RefreshWeatherDataAsync();
        }, 30.EveryMinutes());
    }
}

Core Features 🎯

1. Multiple Trigger Types 🎪

// Cron expressions
_scheduler.ScheduleJob("CronJob", DoWork, "0 */2 * * *".Cron());

// Simple intervals
_scheduler.ScheduleJob("IntervalJob", DoWork, 15.EveryMinutes());

// Daily at specific time
_scheduler.ScheduleJob("DailyJob", DoWork, 9.Hours().DailyAt());

// Business days only (skip weekends/holidays)
_scheduler.ScheduleJob("BusinessJob", DoWork, 
    new BusinessDayTrigger(TimeSpan.FromHours(9)));

// One-time execution
_scheduler.ScheduleJob("OneTimeJob", DoWork, 
    DateTimeOffset.Now.AddHours(2).RunOnceAt());

2. Advanced Retry Policies 🔄

_scheduler.ScheduleJob("PaymentProcessing", async (ct) =>
{
    await ProcessPaymentAsync();
}, 5.EveryMinutes(), new RetryPolicy
{
    MaxRetries = 5,
    BackoffStrategy = RetryBackoffStrategy.Exponential,
    InitialDelay = TimeSpan.FromSeconds(1),
    MaxDelaySeconds = 300,
    ShouldRetry = ex => ex is not BusinessException
});

3. Stateful Jobs 🏢

public class ReportGenerationState
{
    public int ReportId { get; set; }
    public string Format { get; set; }
    public int AttemptCount { get; set; }
}

var state = new ReportGenerationState { ReportId = 123, Format = "PDF" };
_scheduler.ScheduleJob("ReportJob", state, async (reportState, ct) =>
{
    reportState.AttemptCount++;
    await GenerateReportAsync(reportState.ReportId, reportState.Format);
}, 1.EveryHours());

4. Distributed Locking 🔒

// Automatic distributed locking for multi-instance deployments
_scheduler.ScheduleJob("ClusterSafeJob", async (ct) =>
{
    // This job will only run on one instance in a cluster
    await PerformClusterSafeOperationAsync();
}, 10.EveryMinutes());

5. Comprehensive Monitoring 📊

// Get job analytics
var analytics = await _scheduler.GetJobAnalyticsAsync(
    jobId, 
    DateTime.Today.AddDays(-7), 
    DateTime.Today);

Console.WriteLine($"Success Rate: {analytics.SuccessRate:P2}");
Console.WriteLine($"Average Duration: {analytics.AverageDuration:mm\\:ss}");
Console.WriteLine($"Total Executions: {analytics.TotalExecutions}");

Enterprise Features 🏢

1. Plugin System 🔌

services.AddShaunebuScheduler()
    .AddSchedulerPlugins(options =>
    {
        options.EnableAuditPlugin = true;     // Log all job executions
        options.EnableMetricsPlugin = true;   // Collect performance metrics
        options.CustomPlugins = [typeof(MyCustomPlugin)];
    });

// Custom plugin example
public class SecurityAuditPlugin : ISchedulerPlugin
{
    public Task OnJobExecutingAsync(IScheduledJob job)
    {
        _auditService.LogJobStart(job.Id, job.Name, DateTime.UtcNow);
        return Task.CompletedTask;
    }
}

2. Alerting System 🚨

// Register alert providers
services.AddShaunebuScheduler()
    .WithEmailAlerts(options =>
    {
        options.SmtpServer = "smtp.company.com";
        options.ToAddresses = ["team@company.com"];
    })
    .WithSlackAlerts("https://hooks.slack.com/...");

// Alerts are automatically sent for:
// - Job failures after retries exhausted
// - Unexpected execution errors
// - System health issues

3. Bulk Operations 📚

// Bulk schedule multiple jobs
var jobs = new[]
{
    new JobDefinition { Name = "Job1", Trigger = "0 * * * *".Cron() },
    new JobDefinition { Name = "Job2", Trigger = 30.EveryMinutes() }
};

await _scheduler.BulkScheduleAsync(jobs);

// Bulk management
await _scheduler.BulkPauseAsync(["Job1", "Job2"]);
await _scheduler.BulkResumeAsync(["Job1"]);
await _scheduler.BulkUnscheduleAsync(["Job2"]);

4. Persistence & Recovery 💾

// SQL Server persistence
services.AddShaunebuScheduler()
    .WithSqlPersistence(connectionString);

// Jobs survive application restarts
// Execution history is preserved
// Failed jobs can be analyzed and retried

Advanced Usage 🛠️

1. Complex Workflow Scheduling

// Chain jobs: Job2 runs after Job1 completes
var job1 = _scheduler.ScheduleJob("DataExtraction", ExtractData, 9.EveryHours());
var job2 = _scheduler.ScheduleJob("DataProcessing", ProcessData, 
    new ChainedTrigger(job1, _scheduler));

// Conditional scheduling based on events
var eventTrigger = new EventTrigger("DataReady", _eventBus);
_scheduler.ScheduleJob("EventDrivenJob", ProcessReadyData, eventTrigger);

2. Custom Triggers

public class MarketHoursTrigger : IScheduleTrigger
{
    public DateTimeOffset? GetNextOccurrence(DateTimeOffset from)
    {
        // Only run during market hours (9:30 AM - 4:00 PM ET)
        var easternTime = TimeZoneInfo.ConvertTime(from, TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time"));
        
        var nextMarketOpen = GetNextMarketOpen(easternTime);
        return new DateTimeOffset(nextMarketOpen, TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time").GetUtcOffset(nextMarketOpen));
    }
}

_scheduler.ScheduleJob("MarketDataJob", CollectMarketData, new MarketHoursTrigger());

3. Health Monitoring Integration

public class SchedulerHealthCheck : IHealthCheck
{
    private readonly IScheduler _scheduler;

    public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
    {
        var jobs = _scheduler.GetScheduledJobs();
        var failedJobs = jobs.Count(j => j.Status == JobStatus.Failed);
        
        return failedJobs > 0 
            ? HealthCheckResult.Degraded($"{failedJobs} jobs in failed state")
            : HealthCheckResult.Healthy("All jobs running normally");
    }
}

MAUI Integration 📱

1. Lifecycle-Aware Scheduling

public partial class App : Application
{
    private readonly IScheduler _scheduler;

    public App(IScheduler scheduler)
    {
        _scheduler = scheduler;
        InitializeComponent();
        MainPage = new MainPage();
    }

    protected override async void OnStart()
    {
        await _scheduler.StartAsync();
    }

    protected override async void OnSleep()
    {
        await _scheduler.StopAsync();
    }

    protected override async void OnResume()
    {
        await _scheduler.StartAsync();
    }
}

2. Background Tasks in MAUI

public class LocationTrackingService
{
    private readonly IScheduler _scheduler;

    public LocationTrackingService(IScheduler scheduler)
    {
        _scheduler = scheduler;
        
        // Schedule location updates every 5 minutes
        _scheduler.ScheduleJob("LocationUpdate", async (ct) =>
        {
            var location = await GetCurrentLocationAsync();
            await SaveLocationAsync(location);
        }, 5.EveryMinutes(), new RetryPolicy { MaxRetries = 3 });
    }
}

Performance Optimization 🚀

1. Configuration Tuning

services.AddShaunebuScheduler(options =>
{
    options.MaxConcurrentJobs = Environment.ProcessorCount * 2;
    options.JobExecutionTimeout = TimeSpan.FromMinutes(10);
    options.ShutdownTimeout = TimeSpan.FromSeconds(60);
    options.ContinueOnFailure = false; // Stop on failure for critical jobs
});

2. Memory Management

// For long-running applications, configure history retention
services.AddShaunebuScheduler()
    .WithSqlPersistence(connectionString)
    .WithHistoryRetention(TimeSpan.FromDays(30)); // Keep 30 days of history

3. Monitoring and Metrics

// Integrate with application metrics
services.AddShaunebuScheduler()
    .WithApplicationInsights()
    .WithPrometheusMetrics();

// Custom metrics collection
services.AddSingleton<ISchedulerPlugin, CustomMetricsPlugin>();

Best Practices 📝

✅ DO:

// Use descriptive job names
_scheduler.ScheduleJob("Customer_Email_Campaign_Processing", ...);

// Implement proper error handling
_scheduler.ScheduleJob("PaymentProcessing", async (ct) =>
{
    try
    {
        await ProcessPaymentsAsync();
    }
    catch (PaymentGatewayException ex)
    {
        _logger.LogError(ex, "Payment gateway unavailable");
        throw; // Let retry policy handle it
    }
}, 5.EveryMinutes());

// Use appropriate retry policies for external dependencies
new RetryPolicy 
{ 
    MaxRetries = 5,
    BackoffStrategy = RetryBackoffStrategy.Exponential,
    ShouldRetry = ex => ex is TransientException
};

❌ DON'T:

// Don't use generic job names
_scheduler.ScheduleJob("Job1", ...); // ❌

// Don't ignore exceptions
_scheduler.ScheduleJob("DataSync", async (ct) =>
{
    await SyncDataAsync(); // ❌ Exceptions are swallowed
});

// Don't schedule too frequently for resource-intensive jobs
_scheduler.ScheduleJob("ReportGeneration", GenerateReport, 10.EverySeconds()); // ❌

Troubleshooting 🔧

Common Issues

Jobs not executing?

• Check MinimumLevel configuration

• Verify trigger configuration

• Check concurrent job limits

Performance issues?

• Reduce batch size for memory-constrained environments

• Increase batch interval for battery-sensitive applications

• Use appropriate retry policies

Memory leaks?

• Ensure proper job disposal

• Configure history retention policies

• Monitor job execution durations

Debugging Configuration

// Enable detailed logging for troubleshooting
services.AddShaunebuScheduler(options =>
{
    options.LogJobExecutions = true;
})
.AddSchedulerPlugins(options =>
{
    options.EnableAuditPlugin = true; // Detailed execution logging
});

// Check scheduler status
var jobs = _scheduler.GetScheduledJobs();
_logger.LogInformation("Active jobs: {Count}", jobs.Count);
foreach (var job in jobs)
{
    _logger.LogInformation("Job: {Name}, Status: {Status}, Next: {NextRun}", 
        job.Name, job.Status, job.NextRun);
}

API Reference 📚

IScheduler Interface

Trigger Extensions

Configuration Options

Migration Guide 🚚

From Quartz.NET

// QUARTZ.NET
var job = JobBuilder.Create<MyJob>()
    .WithIdentity("myJob", "group1")
    .Build();

var trigger = TriggerBuilder.Create()
    .WithIdentity("myTrigger", "group1")
    .WithCronSchedule("0 0/5 * * * ?")
    .Build();

scheduler.ScheduleJob(job, trigger);

// SHAUNEBU SCHEDULER
_scheduler.ScheduleJob("MyJob", async (ct) => 
{
    await MyJob.Execute();
}, "0 0/5 * * * ?".Cron());

From Hangfire

// HANGFIRE
RecurringJob.AddOrUpdate<MyService>(
    "my-job", 
    x => x.DoWork(), 
    "*/5 * * * *");

// SHAUNEBU SCHEDULER  
_scheduler.ScheduleJob("MyJob", async (ct) =>
{
    await myService.DoWork();
}, "*/5 * * * *".Cron());

Examples 🎨

E-commerce Order Processing

public class OrderProcessingService
{
    private readonly IScheduler _scheduler;

    public OrderProcessingService(IScheduler scheduler)
    {
        _scheduler = scheduler;
        
        // Process abandoned carts every hour
        _scheduler.ScheduleJob("AbandonedCartProcessing", async (ct) =>
        {
            var abandonedCarts = await _cartService.GetAbandonedCartsAsync();
            foreach (var cart in abandonedCarts)
            {
                await _emailService.SendReminderAsync(cart);
            }
        }, 1.EveryHours(), new RetryPolicy { MaxRetries = 3 });

        // Clean up old orders daily at 2 AM
        _scheduler.ScheduleJob("OrderCleanup", async (ct) =>
        {
            await _orderService.CleanupOldOrdersAsync();
        }, 2.Hours().DailyAt());
    }
}

IoT Data Collection

public class IoTDataService
{
    public IoTDataService(IScheduler scheduler)
    {
        // Collect sensor data every 30 seconds with aggressive retry
        _scheduler.ScheduleJob("SensorDataCollection", async (ct) =>
        {
            var sensorReadings = await _sensorNetwork.ReadAllSensorsAsync();
            await _dataLake.StoreReadingsAsync(sensorReadings);
        }, 30.EverySeconds(), new RetryPolicy
        {
            MaxRetries = 10,
            BackoffStrategy = RetryBackoffStrategy.Linear,
            InitialDelay = TimeSpan.FromSeconds(1)
        });

        // Health check every 5 minutes
        _scheduler.ScheduleJob("DeviceHealthCheck", async (ct) =>
        {
            var healthStatus = await _sensorNetwork.CheckHealthAsync();
            if (!healthStatus.IsHealthy)
            {
                await _alertService.SendAlertAsync(healthStatus);
            }
        }, 5.EveryMinutes());
    }
}

Financial Reporting

public class FinancialReportService
{
    public FinancialReportService(IScheduler scheduler)
    {
        // End-of-day reports at 6 PM on business days
        _scheduler.ScheduleJob("EODReporting", async (ct) =>
        {
            var report = await _reportGenerator.GenerateEODReportAsync();
            await _distributionService.DistributeReportAsync(report);
        }, new BusinessDayTrigger(TimeSpan.FromHours(18)));

        // Monthly reconciliation on first business day of month
        _scheduler.ScheduleJob("MonthlyReconciliation", async (ct) =>
        {
            await _accountingService.ReconcileAccountsAsync();
        }, "0 0 1 * *".Cron()); // 1st day of month at midnight
    }
}