# 10.5 Schedule it, with retries

`ManifestNames.cs`:

```csharp compile=app file=ManifestNames.cs
namespace Shopfront;

// The external id of each manifest Shopfront schedules: its identity on every start and every host.
public static class ManifestNames
{
    public const string StockReport = "stock-report";
    public const string LowStockCheck = "low-stock-check";
    public const string Restock = "restock";
}
```

`Program.cs`:

```csharp compile=app file=Program.cs
using Shopfront;
using Shopfront.Auth;
using Shopfront.Data;
using Shopfront.Extensions;
using Shopfront.Staff;
using Shopfront.Suppliers;
using Shopfront.Trains.LowStockCheck;
using Shopfront.Trains.Restock;
using Shopfront.Trains.StockReport;
using Trax.Api.Auth.Jwt;
using Trax.Api.Dashboard.Extensions;
using Trax.Api.GraphQL.Extensions;
using Trax.Effect.Data.Extensions;
using Trax.Effect.Data.Postgres.Extensions;
using Trax.Effect.Data.Services.DomainContext;
using Trax.Effect.Enums;
using Trax.Effect.Extensions;
using Trax.Effect.JunctionProvider.Logging.Extensions;
using Trax.Effect.Models.Manifest;
using Trax.Effect.Provider.Parameter.Extensions;
using Trax.Mediator.Extensions;
using Trax.Scheduler.Extensions;
using Trax.Scheduler.Services.Scheduling;

var builder = WebApplication.CreateBuilder(args);

var connectionString =
    builder.Configuration.GetConnectionString("Shopfront")
    ?? throw new InvalidOperationException("ConnectionStrings:Shopfront is not set.");
var development = builder.Environment.IsDevelopment();

builder.Services.AddShopfront(connectionString);

if (development)
    builder.Services.AddTraxJwtAuth(jwt =>
        jwt.UseSymmetricKey(DevJwt.Issuer, DevJwt.Audience, DevJwt.Key)
    );
else
    builder.Services.AddTraxJwtAuth(
        builder.Configuration["Auth:Authority"]
            ?? throw new InvalidOperationException("Auth:Authority is not set."),
        builder.Configuration["Auth:Audience"]
            ?? throw new InvalidOperationException("Auth:Audience is not set.")
    );
builder.Services.AddAuthorization();

builder.Services.AddTrax(trax =>
    trax.AddEffects(effects =>
            effects
                .UsePostgres(connectionString)
                .SaveTrainParameters()
                .AddJunctionLogger(serializeJunctionData: true)
                .AddDecisionRecording()
                .AddJunctionEvents()
                .AddLifecycleHook<StaffFailureHook>()
        )
        .AddMediator(typeof(Program).Assembly)
        .AddScheduler(scheduler =>
        {
            // In Development, retries come seconds apart rather than minutes, to be watched.
            if (development)
                scheduler
                    .DefaultRetryDelay(TimeSpan.FromSeconds(5))
                    .MaxRetryDelay(TimeSpan.FromSeconds(30));

            return scheduler
                .Schedule<IStockReportTrain>(
                    ManifestNames.StockReport,
                    new StockReportInput(),
                    Cron.Daily(hour: 2),
                    options =>
                        options
                            // The shop's holidays: no count, and none the morning after.
                            .Exclude(
                                Exclude.Dates(new DateOnly(2026, 12, 25), new DateOnly(2027, 1, 1))
                            )
                            .OnMisfire(MisfirePolicy.DoNothing)
                            .Variance(TimeSpan.FromMinutes(10))
                )
                .ThenInclude<ILowStockCheckTrain>(
                    ManifestNames.LowStockCheck,
                    new LowStockCheckInput { Threshold = 3 }
                )
                .Schedule<IRestockTrain>(
                    ManifestNames.Restock,
                    new RestockInput { Threshold = 3 },
                    development ? Every.Minutes(1) : Every.Hours(1),
                    options => options.MaxRetries(2)
                );
        })
);
builder.Services.AddTraxGraphQL(graphql =>
    graphql
        .AddDbContext<ShopfrontDbContext>()
        .ExposeOperationQueries()
        .ExposeOperationMutations()
        .GateOperations(roles: Roles.Staff)
);

var app = builder.Build();

await app.Services.EnsureSchemaCreatedAsync<ShopfrontDbContext>();

app.UseAuthentication();
app.UseAuthorization();
app.UseTraxGraphQL();
app.UseTraxApiDashboard(dashboard => dashboard.AllowAnonymousShell());

if (development)
{
    app.MapGet(
            "/dev/token/{user}",
            (string user, bool staff = false) =>
                DevJwt.Mint(user, staff ? Roles.Staff : Roles.Customer)
        )
        .AllowAnonymous();

    // Takes the fake supplier down, or brings it back.
    app.MapPost(
            "/dev/supplier/{state}",
            (string state, FakeSupplier supplier) =>
            {
                supplier.IsDown = state == "down";
                return Results.NoContent();
            }
        )
        .AllowAnonymous();
}

await app.RunAsync();
```

What is new:

- **`MaxRetries(2)`** retries a failed restock twice, so it runs at most three times. The third
  failure makes it a dead letter.
- **The backoff** spaces the retries out. The first waits `DefaultRetryDelay`, five minutes by
  default, and each one after it waits twice as long as the last, up to `MaxRetryDelay`, an hour by
  default. Development uses five seconds and thirty, so the whole story takes less than a minute.
  These are the scheduler's settings, shared by every manifest.
- **`AddLifecycleHook<StaffFailureHook>()`** registers the hook. It goes last in `AddEffects`,
  after the effects that need the data provider before them.
- **The restock runs every hour**, and every minute in Development.
- **`/dev/supplier/{state}`** flips the fake supplier, in Development only.

## SDK Reference

> [Schedule](/docs/sdk-reference/scheduler-api/schedule) | [AddScheduler](/docs/sdk-reference/scheduler-api/add-scheduler) | [How retries work](/docs/scheduler/how-retries-work) | [Resolve a dead letter](/docs/scheduler/dead-letters-and-cleanup) | [AddLifecycleHook](/docs/sdk-reference/configuration/add-lifecycle-hook)

---

Next: [10.6 Watch it fail](/docs/book/failures-retries-and-dead-letters/watch-it-fail)