Automatic Cron Seeding

TickerQ can automatically seed cron jobs from [TickerFunction] attributes that include cron expressions.

How It Works

When TickerQ starts, it scans all methods marked with [TickerFunction] attributes that have a cronExpression parameter. These cron jobs are automatically created (upserted) in the database.

Example: Defining Cron Jobs with Attributes

public class ScheduledJobs
{
    [TickerFunction("GenerateDailyReport", "0 0 9 * * *")] // Daily at 9 AM
    public async Task GenerateDailyReport(
        TickerFunctionContext context,
        CancellationToken cancellationToken)
    {
        // Your job logic
    }
    
    [TickerFunction("CleanupLogs", "0 0 0 * * *")] // Daily at midnight
    public async Task CleanupLogs(
        TickerFunctionContext context,
        CancellationToken cancellationToken)
    {
        // Your cleanup logic
    }
    
    [TickerFunction("SendWeeklyDigest", "0 0 8 * * 1")] // Every Monday at 8 AM
    public async Task SendWeeklyDigest(
        TickerFunctionContext context,
        CancellationToken cancellationToken)
    {
        // Your email digest logic
    }
}

Automatic Behavior

By default, automatic seeding is enabled. When your application starts:

1. TickerQ scans for all [TickerFunction] attributes with cron expressions
2. Creates CronTickerEntity entries in the database
3. Uses upsert logic (inserts new, doesn't update existing)

Seeding Logic

The seeding uses upsert logic based on:

• Function name
• Expression (cron expression)
• Request (must be empty for seeded jobs)

Important: If a cron ticker with the same Function, Expression, and empty Request already exists, it will not be updated. This prevents overwriting manually configured cron jobs.

Configuration

Automatic seeding is enabled by default. No configuration is required:

builder.Services.AddTickerQ(options =>
{
    options.AddOperationalStore(efOptions =>
    {
        efOptions.UseTickerQDbContext<TickerQDbContext>(optionsBuilder =>
        {
            optionsBuilder.UseNpgsql(connectionString);
        });
        // Automatic seeding is enabled by default
    });
});

When to Use

Use automatic seeding when:

• You want cron jobs defined in code via attributes
• You prefer code-based configuration over database configuration
• You want to version control your cron job definitions
• Your cron expressions are static and don't change at runtime

Limitations

• Only works with cron expressions (not one-time jobs)
• Jobs are seeded with empty Request data
• Expression and Function must match exactly for upsert logic
• Cannot seed jobs with custom properties (use custom seeding instead)

Disabling Automatic Seeding

To disable automatic seeding, use IgnoreSeedDefinedCronTickers():

options.AddOperationalStore(efOptions =>
{
    efOptions.UseTickerQDbContext<TickerQDbContext>(optionsBuilder =>
    {
        optionsBuilder.UseNpgsql(connectionString);
    });
    efOptions.IgnoreSeedDefinedCronTickers(); // Disable automatic seeding
});

See Disable Seeding for more details.

Logging

Automatic seeding operations are logged:

[INF] TickerQ start seeding data: SeedDefinedCronTickers(CronTickerEntity)
[INF] TickerQ completed seeding data: SeedDefinedCronTickers(CronTickerEntity)

With OpenTelemetry instrumentation, you'll see:

• tickerq.seeding.started activity
• tickerq.seeding.completed activity

Troubleshooting

Jobs not being seeded?

• Verify [TickerFunction] has a cronExpression parameter
• Check that Entity Framework Core persistence is configured
• Ensure cron expression is valid (6-part format)
• Review application logs for seeding errors

Jobs being overwritten?

• Seeding uses upsert logic and won't update existing jobs
• Only jobs with matching Function, Expression, and empty Request are skipped

Multiple nodes seeding?

• Each node will attempt to seed, but upsert logic prevents duplicates
• Safe to run in multi-node environments

See Also

• Custom Seeding - Programmatic seeding for more control
• Disable Seeding - Prevent automatic seeding