> For the complete documentation index, see [llms.txt](https://brightercommand.gitbook.io/paramore-brighter-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://brightercommand.gitbook.io/paramore-brighter-documentation/outbox-and-inbox/brighterinboxsupport/spannerinbox.md). # Spanner Inbox The Spanner Inbox records the messages a consumer has already handled in a Google Cloud Spanner table, so a redelivery is recognised rather than reprocessed. > **Reference** · Applies to **Brighter V10** · Prerequisites: [Inbox Support](/paramore-brighter-documentation/outbox-and-inbox/brighterinboxsupport.md) The Spanner Inbox records the messages a consumer has already handled in a Google Cloud Spanner table, so a redelivery is recognised rather than reprocessed. It is configured entirely through the shared relational configuration. ## Spanner Inbox Configuration ```powershell dotnet add package Paramore.Brighter.Inbox.Spanner dotnet add package Paramore.Brighter.Spanner ``` **The class is `SpannerInboxAsync`, and there is no synchronous twin.** It implements Brighter's inbox interfaces through `RelationalDatabaseInbox`, so it is used exactly like any other Inbox; only the name is different. ```csharp using Microsoft.Extensions.DependencyInjection; using Paramore.Brighter; using Paramore.Brighter.Inbox; using Paramore.Brighter.Inbox.Spanner; using Paramore.Brighter.ServiceActivator.Extensions.DependencyInjection; public static class SpannerInboxRegistration { public static void ConfigureServices(IServiceCollection services) { var configuration = new RelationalDatabaseConfiguration( connectionString: "Data Source=projects/my-project/instances/my-instance/databases/brighter", inboxTableName: "Inbox"); services.AddSingleton(configuration); services.AddConsumers(options => { options.InboxConfiguration = new InboxConfiguration( new SpannerInboxAsync(configuration), scope: InboxScope.Commands, onceOnly: true, actionOnExists: OnceOnlyAction.Warn); // ... your subscriptions and channel factory }); } } ``` Before Brighter 10.8.0 this configuration took effect only in an application that also called `AddProducers`; see [Global Inbox Configuration in a Consumer-Only Application](/paramore-brighter-documentation/outbox-and-inbox/brighterinboxsupport.md#global-inbox-configuration-in-a-consumer-only-application). Constructed with the configuration alone, `SpannerInboxAsync` builds its own `SpannerConnectionProvider`; a second constructor takes an `IAmARelationalDbConnectionProvider` when you want to share one. ## Spanner Inbox Options **The Spanner Inbox has no options type of its own.** It takes an `IAmARelationalDatabaseConfiguration`, the type every relational Outbox, Inbox, provisioner and queue-table transport takes, and its options are documented once at [Relational Database Configuration Reference](/paramore-brighter-documentation/brighter-configuration/brighterbasicconfiguration/relationaldatabaseconfigurationreference.md#relational-database-configuration-options). That is why this page has no table: there is no Spanner Inbox surface to tabulate. The option that matters here is **`inboxTableName`**, which defaults to `Inbox`. Note the asymmetry the reference page records — the constructor parameter is `inboxTableName` and the property you read back is `InBoxTableName`, with a capital `B`. `schemaName` is not used: Spanner does not organise tables into schemas the way the other relational backends do, and its provisioning extensions take no `schemaName` argument. ## Provisioning the Spanner Inbox You have the same two options every relational Inbox has. **Option A — let Brighter provision it.** `AddSpannerInbox` registers a provisioner that creates the table at startup; see [Configuring Box Provisioning](/paramore-brighter-documentation/outbox-and-inbox/boxprovisioning/boxprovisioningconfiguration.md#spanner). Spanner uses the **degenerate runner** — it creates the table on a fresh database and cannot evolve an existing one, so an Inbox table created by an earlier Brighter release needs its new columns added by hand. See [Per-backend differences to be aware of](/paramore-brighter-documentation/outbox-and-inbox/boxprovisioning.md#per-backend-differences-to-be-aware-of), and [Replay On Seen Reference](/paramore-brighter-documentation/outbox-and-inbox/replayonseen/replayonseenreference.md) for the causation column that [replay on seen](/paramore-brighter-documentation/outbox-and-inbox/replayonseen.md) needs on both boxes. **Option B — manage the DDL yourself.** `SpannerInboxBuilder.GetDDL()` returns the DDL Brighter ships: ```csharp using Paramore.Brighter.Inbox.Spanner; public static class SpannerInboxDdl { public static string Ddl() => SpannerInboxBuilder.GetDDL("Inbox"); } ``` The table is keyed on `(CommandId, ContextKey)`, so the same command handled by two different handlers is two rows rather than a collision: ```sql CREATE TABLE IF NOT EXISTS `Inbox`( `CommandId` STRING(256) NOT NULL, `CommandType` STRING(256), `CommandBody` JSON, `Timestamp` TIMESTAMP, `ContextKey` STRING(256), `CausationId` STRING(256) ) PRIMARY KEY (`CommandId`, `ContextKey`) ``` `CausationId` arrives at Brighter 10.8.0. A table an earlier release created still records commands without it, but [Replay On Seen](/paramore-brighter-documentation/outbox-and-inbox/replayonseen/replayonseenreference.md#store-support) needs it, and the Spanner provisioner adds it only on a fresh install, so add it by hand to an existing table. Duplicate inserts surface as a `SpannerException` carrying an `AlreadyExists` status, which the Inbox translates into the `OnceOnlyAction` you configured. ## Further Reading * [Inbox Support](/paramore-brighter-documentation/outbox-and-inbox/brighterinboxsupport.md) — what an Inbox is for and when you need one * [Relational Database Configuration Reference](/paramore-brighter-documentation/brighter-configuration/brighterbasicconfiguration/relationaldatabaseconfigurationreference.md) — every option this Inbox takes * [Spanner Outbox](/paramore-brighter-documentation/outbox-and-inbox/brighteroutboxsupport/spanneroutbox.md) — the same configuration type, one family over * [Database Provisioning](/paramore-brighter-documentation/outbox-and-inbox/boxprovisioning.md) — the migration machinery, and why Spanner's runner is degenerate * [Dispatcher Configuration Reference](/paramore-brighter-documentation/brighter-configuration/brighterbasicconfiguration/dispatcherconfigurationreference.md#inbox) — where `InboxConfiguration` fits --- # Agent Instructions This documentation is published with GitBook. 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