ScheduleMany / ScheduleManyAsync

Batch-schedules multiple instances of a train from a collection. All manifests are created or updated in a single transaction. Supports automatic cleanup of stale manifests via prunePrefix.

ScheduleMany is used at startup configuration time; ScheduleManyAsync is used at runtime via ITraxScheduler.

Signatures

Startup: Name-Based with ManifestItem (Recommended)

public SchedulerConfigurationBuilder ScheduleMany<TTrain>(
    string name,
    IEnumerable<ManifestItem> items,
    Schedule schedule,
    Action<ScheduleOptions>? options = null
)
    where TTrain : class

The name parameter automatically derives:

groupId = name
prunePrefix = "{name}-"
externalId = "{name}-{item.Id}" for each item

Each ManifestItem contains the item's ID and input. The input type is inferred from TTrain's IServiceTrain<TInput, TOutput> interface and validated at configuration time. The output type is not constrained — scheduled trains can return any output type, and the output is discarded for background jobs.

Startup: Unnamed with ManifestItem

public SchedulerConfigurationBuilder ScheduleMany<TTrain>(
    IEnumerable<ManifestItem> items,
    Schedule schedule,
    Action<ScheduleOptions>? options = null
)
    where TTrain : class

Each ManifestItem.Id is used as the full external ID (no name prefix applied).

ManifestItem

public sealed record ManifestItem(
    string Id,
    IManifestProperties Input,
    string? DependsOn = null
);

Property	Type	Description
`Id`	`string`	The item's identifier. In name-based overloads, this becomes the suffix (full external ID = `"{name}-{Id}"`). In unnamed overloads, this is the full external ID.
`Input`	`IManifestProperties`	The train input for this item. Must match the expected input type of `TTrain`.
`DependsOn`	`string?`	The external ID of the parent manifest this item depends on. Used by `IncludeMany` and `ThenIncludeMany`. See Dependent Scheduling.

Startup: Explicit Type Parameters (Legacy)

The four-type-parameter forms are still available for backward compatibility:

// Name-based
public SchedulerConfigurationBuilder ScheduleMany<TTrain, TInput, TOutput, TSource>(
    string name,
    IEnumerable<TSource> sources,
    Func<TSource, (string Suffix, TInput Input)> map,
    Schedule schedule,
    Action<ScheduleOptions>? options = null,
    Action<TSource, ManifestOptions>? configureEach = null
)
    where TTrain : IServiceTrain<TInput, TOutput>
    where TInput : IManifestProperties
 
// Explicit
public SchedulerConfigurationBuilder ScheduleMany<TTrain, TInput, TOutput, TSource>(
    IEnumerable<TSource> sources,
    Func<TSource, (string ExternalId, TInput Input)> map,
    Schedule schedule,
    Action<ScheduleOptions>? options = null,
    Action<TSource, ManifestOptions>? configureEach = null
)
    where TTrain : IServiceTrain<TInput, TOutput>
    where TInput : IManifestProperties

Runtime (ITraxScheduler)

Task<IReadOnlyList<Manifest>> ScheduleManyAsync<TTrain, TInput, TOutput, TSource>(
    IEnumerable<TSource> sources,
    Func<TSource, (string ExternalId, TInput Input)> map,
    Schedule schedule,
    Action<ScheduleOptions>? options = null,
    Action<TSource, ManifestOptions>? configureEach = null,
    CancellationToken ct = default
)
    where TTrain : IServiceTrain<TInput, TOutput>
    where TInput : IManifestProperties

Type Parameters

ManifestItem API (Recommended)

Type Parameter	Constraint	Description
`TTrain`	`class`	The train interface type. Can implement `IServiceTrain<TInput, TOutput>` with any output type. The input type is inferred at configuration time. The output is discarded for background jobs.

Legacy / Runtime API

Type Parameter	Constraint	Description
`TTrain`	`IServiceTrain<TInput, TOutput>`	The train interface type. All items in the batch execute the same train. Can have any output type — the output is discarded for background jobs.
`TInput`	`IManifestProperties`	The input type for the train. Each item in the batch can have different input data.
`TOutput`	—	The output type of the train. Not constrained — any output type is accepted. The output is discarded when jobs complete.
`TSource`	—	The type of elements in the source collection. Can be any type — it is transformed into `(ExternalId, Input)` pairs by the `map` function.

Parameters

ManifestItem API (Recommended)

Parameter	Type	Required	Default	Description
`name`	`string`	Yes (name-based)	—	The batch name. Automatically derives `groupId` = `name`, `prunePrefix` = `"{name}-"`, and each external ID = `"{name}-{item.Id}"`.
`items`	`IEnumerable<ManifestItem>`	Yes	—	The collection of items to create manifests from. Each item becomes one scheduled manifest.
`schedule`	`Schedule`	Yes	—	The schedule definition applied to all manifests in the batch. Use Every or Cron helpers.
`options`	`Action<ScheduleOptions>?`	No	`null`	Optional callback to configure all scheduling options. The name-based overload pre-sets `Group(name)` and `PrunePrefix("{name}-")` before invoking your callback. See ScheduleOptions.

Legacy API Parameters

Parameter	Type	Required	Default	Description
`name`	`string`	Yes (name-based)	—	The batch name. Automatically derives `groupId` = `name`, `prunePrefix` = `"{name}-"`, and each external ID = `"{name}-{suffix}"`.
`sources`	`IEnumerable<TSource>`	Yes	—	The collection of items to create manifests from. Each item becomes one scheduled manifest.
`map`	`Func<TSource, (string, TInput)>`	Yes	—	A function that transforms each source item into an ID/suffix and input pair.
`schedule`	`Schedule`	Yes	—	The schedule definition applied to all manifests in the batch.
`options`	`Action<ScheduleOptions>?`	No	`null`	Optional callback to configure all scheduling options. See ScheduleOptions.
`configureEach`	`Action<TSource, ManifestOptions>?`	No	`null`	Optional callback to set per-item manifest options. Receives both the source item and options, allowing per-item overrides of the base options set via `options`.
`ct`	`CancellationToken`	No	`default`	Cancellation token (runtime API only).

Returns

Startup: SchedulerConfigurationBuilder — for continued fluent chaining.
Runtime: Task<IReadOnlyList<Manifest>> — all created or updated manifest records.

Examples

Basic Batch Scheduling with ManifestItem (Recommended)

var tables = new[] { "customers", "orders", "products" };
 
services.AddTrax(trax => trax
    .AddScheduler(scheduler => scheduler
        .ScheduleMany<ISyncTableTrain>(
            "sync",
            tables.Select(table => new ManifestItem(
                table,
                new SyncTableInput { TableName = table }
            )),
            Every.Minutes(5))
    )
);
// Creates: sync-customers, sync-orders, sync-products
// groupId: "sync", prunePrefix: "sync-"

Each ManifestItem contains the item's ID (used as the suffix in name-based overloads) and the train input. No map function needed — the data is already structured.

Unnamed Batch Scheduling

var tables = new[] { "customers", "orders", "products" };
 
scheduler.ScheduleMany<ISyncTableTrain>(
    tables.Select(table => new ManifestItem(
        $"sync-{table}",
        new SyncTableInput { TableName = table }
    )),
    Every.Minutes(5));

With Pruning (Automatic Stale Cleanup)

The name-based overload includes pruning automatically (prunePrefix: "{name}-"):

// If "partners" was in a previous deployment but removed from this list,
// its manifest ("sync-partners") will be deleted because it starts with
// "sync-" but wasn't included in the current batch.
var tables = new[] { "customers", "orders" };
 
scheduler.ScheduleMany<ISyncTableTrain>(
    "sync",
    tables.Select(table => new ManifestItem(
        table,
        new SyncTableInput { TableName = table }
    )),
    Every.Minutes(5));

With Group Configuration

scheduler.ScheduleMany<ISyncTableTrain>(
    "sync",
    tables.Select(table => new ManifestItem(
        table,
        new SyncTableInput { TableName = table }
    )),
    Every.Minutes(5),
    options => options
        .Priority(10)
        .Group(group => group
            .MaxActiveJobs(5)
            .Priority(20)));

Legacy API with Map Function

The three-type-parameter form is still available and supports per-item configuration via configureEach:

scheduler.ScheduleMany<ISyncTableTrain, SyncTableInput, Unit, string>(
    tables,
    table => ($"sync-{table}", new SyncTableInput { TableName = table }),
    Every.Minutes(5),
    options => options.Priority(10),
    configureEach: (table, opts) =>
    {
        if (table == "orders")
        {
            opts.MaxRetries = 10;
            opts.Priority = 25;
        }
    });

Runtime Scheduling

public class TenantSyncService(ITraxScheduler scheduler)
{
    public async Task SyncTenants(IEnumerable<Tenant> tenants)
    {
        var manifests = await scheduler.ScheduleManyAsync<ISyncTenantTrain, SyncTenantInput, Unit, Tenant>(
            sources: tenants,
            map: tenant => (
                ExternalId: $"tenant-sync-{tenant.Id}",
                Input: new SyncTenantInput { TenantId = tenant.Id, Name = tenant.Name }
            ),
            schedule: Every.Hours(1),
            options => options
                .PrunePrefix("tenant-sync-")
                .Group("tenant-syncs"));
    }
}

Remarks

All manifests are created/updated in a single database transaction. If any manifest fails to save, the entire batch is rolled back.
Pruning runs in a separate database context after the main transaction commits. A prune failure does not roll back the upserted manifests — the failure is logged as a warning and retried on the next cycle.
The configureEach callback receives Action<TSource, ManifestOptions> (not Action<ManifestOptions> like Schedule) — this lets you customize options based on the source item. It applies per-item overrides on top of the base options from ScheduleOptions.
The source collection is materialized (.ToList()) internally to avoid multiple enumeration.
The group is configured via .Group(...) on ScheduleOptions. Per-group settings (MaxActiveJobs, Priority, IsEnabled) can be set from code or adjusted at runtime from the dashboard. See Per-Group Dispatch Controls.
ScheduleMany cannot be followed by .ThenInclude() — use IncludeMany (with dependsOn) instead for batch dependent scheduling.