Cron Jobs

Cron jobs are scheduled background tasks that run at specified intervals using cron expressions.

TickerFunction Attribute

Use the [TickerFunction] attribute to mark methods as scheduled jobs:

[TickerFunction("JobName", "cron-expression")]
public async Task YourJobMethod(CancellationToken cancellationToken)
{
    // Your job logic here
}

Example: Auto-Reject Stale Requests

Here's a real example from our demo that auto-rejects approved requests after 3 minutes:

public class BackgroundJobs(IRepository<RequestEntity> _requestRepository, IRepository<RequestLog> _logRepository, IRepository<Report> _reportRepository, ILogger<RequestEntity> logger)
{
    [TickerFunction("AutoReject", "*/30 * * * *")]
    public async Task RejectStaleApprovedRequests(CancellationToken cancellationToken)
    {
        // Get all approved requests that are older than 3 minutes
        var threeMinutesAgo = DateTime.UtcNow.AddMinutes(-3);
        var staleApprovedRequests = await _requestRepository.GetAllAsync(r =>
            r.Status == RequestStatus.Approved &&
            r.ApprovedAt.HasValue &&
            r.ApprovedAt.Value < threeMinutesAgo);
        
        Console.WriteLine("The Background Job is running //////////////////////////////////////");
        
        foreach (var request in staleApprovedRequests)
        {
            try
            {
                await UpdateRequestStatus(request.Id, RequestStatus.Rejected, 
                    "Auto-rejected: Approved for more than 3 minutes without completion");
            }
            catch (Exception ex)
            {
                await LogError(request.Id, $"Error rejecting stale request: {ex.Message}");
            }
        }
    }
}

Example: Report Generation

Another example that creates reports:

[TickerFunction("CreateReport")]
public async Task CreateReport(TickerFunctionContext tickerContext, CancellationToken cancellationToken)
{
    var report = new Report
    {
        Title = $"Scheduled Report - {DateTime.UtcNow:yyyy-MM-dd HH:mm}",
        Content = $"This is an automatically generated report created at {DateTime.UtcNow:yyyy-MM-dd HH:mm:ss}",
        CreatedAt = DateTime.UtcNow
    };

    await _reportRepository.AddAsync(report);
    await _reportRepository.SaveAsync();
    logger.LogInformation($"Report created with ID: {report.Id}");
}

Cron Expression Syntax

TickerQ uses standard cron expressions:

Field	Values	Special Characters
Minute	0-59	* , - /
Hour	0-23	* , - /
Day	1-31	* , - / ? L W
Month	1-12	* , - /
Day of Week	0-7	* , - / ? L #

Common Patterns

"*/30 * * * *"     // Every 30 seconds
"0 * * * *"        // Every hour
"0 0 * * *"        // Daily at midnight
"0 0 * * 1"        // Weekly on Monday
"0 0 1 * *"        // Monthly on the 1st
"0 9-17 * * 1-5"   // Every hour from 9 AM to 5 PM, Monday to Friday

Primary Constructor Pattern

Use primary constructors for dependency injection:

public class BackgroundJobs(
    IRepository<RequestEntity> _requestRepository, 
    IRepository<RequestLog> _logRepository, 
    IRepository<Report> _reportRepository, 
    ILogger<RequestEntity> logger)
{
    // Your job methods here
}

TickerFunctionContext

For jobs that need access to context data:

[TickerFunction("JobWithData", "*/1 * * * *")]
public async Task ProcessData(TickerFunctionContext<MyDataType> context, CancellationToken cancellationToken)
{
    var data = context.Request; // Access your typed data
    // Process the data
}

Best Practices

1. Use meaningful job names that describe what the job does
2. Handle exceptions within your job methods
3. Use CancellationToken for cancellation support
4. Log job execution for monitoring and debugging
5. Keep jobs lightweight - avoid long-running operations
6. Use dependency injection for accessing services

Service Registration

Register your job classes in Program.cs:

builder.Services.AddScoped<BackgroundJobs>();

Next Steps

Learn about Time Jobs for one-time scheduled tasks.