Koan.Data.Cqrs.Outbox.Mongo 0.5.2

Koan.Data.Cqrs.Outbox.Mongo

MongoDB-backed IOutboxStore for Koan's implicit CQRS pipeline.

• Durable outbox storage using MongoDB
• Leased dequeuing to avoid concurrent delivery
• Unique index on DedupKey (if provided in the future)

Quick start

• Just reference this package and the provider will be discovered automatically. The outbox selector picks the highest ProviderPriority and prefers Mongo over the in-memory default.
• Optionally, call services.AddMongoOutbox() to register explicitly or to override options in code.

Install and enable

1. Configure from appsettings (bound from Koan:Cqrs:Outbox:Mongo). Connection will resolve in this order:

• options.ConnectionString (explicit)
• Koan:Data:Sources:{name}:mongo:ConnectionString (named source; {name} = ConnectionStringName, default "mongo")
• ConnectionStrings:{name}

Example appsettings.json (named connection via ConnectionStrings)

{
  "Koan": {
    "Cqrs": {
      "Outbox": {
        "Mongo": {
          // ConnectionStringName defaults to "mongo"; set explicitly if you like
          "ConnectionStringName": "mongo",
          "Database": "Koan",
          "Collection": "Outbox",
          "LeaseSeconds": 30,
          "MaxAttempts": 10
        }
      }
    }
  },
  "ConnectionStrings": {
    "mongo": "mongodb://localhost:27017"
  }
}

Alternative (inline connection string under Koan:Cqrs:Outbox:Mongo)

{
  "Koan": {
    "Cqrs": {
      "Outbox": {
        "Mongo": {
          "ConnectionString": "mongodb://localhost:27017",
          "Database": "Koan",
          "Collection": "Outbox"
        }
      }
    }
  }
}

2. Register the store in your service setup:

services.AddMongoOutbox(); // binds from Koan:Cqrs:Outbox:Mongo and defaults name to "mongo"

Or override via options:

services.AddMongoOutbox(o ⇒ { o.ConnectionStringName = "custom-mongo"; // or set o.ConnectionString directly o.Database = "Koan"; o.Collection = "Outbox"; o.LeaseSeconds = 30; o.MaxAttempts = 10; });

Notes:

• Cqrs initializer registers a default in-memory outbox. Adding Mongo will override it (highest ProviderPriority wins; explicit registration also works).
• The outbox processor (in Koan.Data.Cqrs) will pick up this store automatically.

Schema and indexes

The store creates indexes on:

• Status + VisibleAt (for efficient pending scans)
• LeaseUntil (to reclaim expired leases)
• DedupKey (unique, sparse)