Stratara.Outbox.RabbitMQ
4.0.4
Prefix Reserved
See the version list below for details.
dotnet add package Stratara.Outbox.RabbitMQ --version 4.0.4
NuGet\Install-Package Stratara.Outbox.RabbitMQ -Version 4.0.4
<PackageReference Include="Stratara.Outbox.RabbitMQ" Version="4.0.4" />
<PackageVersion Include="Stratara.Outbox.RabbitMQ" Version="4.0.4" />
<PackageReference Include="Stratara.Outbox.RabbitMQ" />
paket add Stratara.Outbox.RabbitMQ --version 4.0.4
#r "nuget: Stratara.Outbox.RabbitMQ, 4.0.4"
#:package Stratara.Outbox.RabbitMQ@4.0.4
#addin nuget:?package=Stratara.Outbox.RabbitMQ&version=4.0.4
#tool nuget:?package=Stratara.Outbox.RabbitMQ&version=4.0.4
Stratara.Outbox.RabbitMQ
Derived. The behaviour described here is specified under
openspec/specs/. Those specifications are the source; this page explains and illustrates them.
License: MIT.
Outbox-pattern command + event dispatch for the Stratara event-sourced stack with a RabbitMQ message-bus implementation. Contains the write-side dispatchers, the outbox-retry worker, the read-side mediator command worker, the RabbitMQ bus, and the Redis-backed ProjectionReplayState that coordinates dispatch skip during projection replay. Azure Service Bus ships separately as Stratara.Outbox.AzureServiceBus.
What's in the box
| Folder | Contents |
|---|---|
Outbox/ |
OutboxOptions, CommandOutboxDispatcher (write-side ICommand fan-out via IMessageBus, falls back to outbox table on bus failure), EventBundleOutboxDispatcher (same for EventBundle), OutboxWorker (hosted service that retries unpublished outbox rows on a polling interval), NullOutboxLock + RedisOutboxLock (IOutboxLock implementations — default no-op for single-instance deployments, Redis-leased distributed lock for multi-replica setups) |
Messaging/ |
RabbitMqBus — IMessageBus over RabbitMQ. Azure Service Bus ships as the sibling Stratara.Outbox.AzureServiceBus package. |
Mediator/ |
MediatorCommandWorker (hosted service that subscribes to the command topic and dispatches into the in-process IMediator) |
Projections/ |
ProjectionReplayState (Redis-backed concrete IProjectionReplayState; dispatchers skip publishing while replay is active), ProjectionReplayOptions (how long the replay marking survives without renewal) |
DependencyInjection/ |
AddOutboxDispatcher(), AddOutboxWorker(IConfiguration), AddRedisOutboxLock() (opt-in distributed lock), AddProjectionReplayState(), AddMediatorWorker(), AddMessaging() |
Diagnostics/Extensions/ |
LoggerOutboxExtensions, LoggerMessagingExtensions (source-generated logger surfaces) |
Quick start
// In your API host:
builder.AddMessaging(); // IMessageBus + MessagingOptions binding
builder.Services
.AddOutboxDispatcher() // CommandOutboxDispatcher + EventBundleOutboxDispatcher + ProjectionReplayState
.AddOutboxWorker(builder.Configuration); // OutboxWorker hosted service (only if this host owns retries)
// In your command worker:
builder.Services
.AddMediatorWorker(); // MediatorCommandWorker hosted service
The dispatchers consult IProjectionReplayState.IsReplayActive before each publish and skip dispatch (writing to the outbox table only) while a replay is in progress. They also record the outbox.published counter for what the broker accepted — the worker counts nothing, because only the dispatcher knows what went out.
The replay marking and its progress counters are held on the lease configured by ProjectionReplayOptions.LeaseSeconds (default 300), which the replay renews every time it reports progress. A replay whose host is killed stops renewing it and the marking lapses on its own, instead of suppressing publication indefinitely. AddProjectionReplayState() registers the options with their defaults; override with services.Configure<ProjectionReplayOptions>(...). Set it longer than the slowest stretch between two progress reports — too short lets the marking lapse while the replay is still running.
A drain cycle takes one batch of each kind and ends. Rows the broker would not accept stay in the table for the next interval; a cycle never re-reads what it just failed to publish, so an unreachable broker or a suppressed drain cannot turn a cycle into a loop over the same rows.
Multi-instance outbox workers
AddOutboxWorker registers NullOutboxLock as the default IOutboxLock — a no-op that preserves the single-instance assumption. For multi-replica deployments call AddRedisOutboxLock() afterwards; it replaces the no-op with a Redis-leased lock (SET stratara:outbox:lock NX EX) so only one replica drains at a time:
builder.AddCaching(); // registers IConnectionMultiplexer
builder.Services
.AddOutboxDispatcher()
.AddOutboxWorker(builder.Configuration)
.AddRedisOutboxLock(); // multi-replica safe
The lease defaults to 60 s (OutboxOptions.LockLeaseSeconds). Tune it so it exceeds the worst-case drain duration; otherwise the lock can expire mid-cycle and a peer may start a concurrent drain. Outbox semantics are still at-least-once, so a duplicate publish is recoverable provided handlers stay idempotent.
Dependencies
Stratara.Abstractions— forICommand,IEvent,IMessageBus,ICommandOutboxDispatcher,IEventBundleOutboxDispatcher,IProjectionReplayState,IMessagingIdentifier,IWriteUnitOfWork(used at runtime via the outbox repository).Stratara.Contracts— forEventBundle+CommandEnvelopemessages.Stratara.Mediator—MediatorCommandWorkerdispatches into the in-processIMediator.Stratara.Sessions— dispatcher hydratesCommandEnvelopefrom the current session context.Stratara.Shared— for messaging primitives, resilience pipeline names, mapping helpers, and the diagnostics base.RabbitMQ.Client,StackExchange.Redis(replay-state + optional outbox-lock).Microsoft.Extensions.Hosting.Abstractions+Microsoft.Extensions.Options.ConfigurationExtensions— for hosted services + options binding.
The outbox dispatcher persists rows through
IWriteUnitOfWork.CreateOutboxRepository— that interface lives inStratara.Abstractions, but the concrete implementation comes fromStratara.EventSourcing.EntityFrameworkCore. Reference that package alongside this one to get a working stack.
| Product | Versions Compatible and additional computed target framework versions. |
|---|---|
| .NET | net10.0 is compatible. net10.0-android was computed. net10.0-browser was computed. net10.0-ios was computed. net10.0-maccatalyst was computed. net10.0-macos was computed. net10.0-tvos was computed. net10.0-windows was computed. |
-
net10.0
- Microsoft.Extensions.Configuration.Abstractions (>= 10.0.11)
- Microsoft.Extensions.DependencyInjection (>= 10.0.11)
- Microsoft.Extensions.Hosting.Abstractions (>= 10.0.11)
- Microsoft.Extensions.Logging.Abstractions (>= 10.0.11)
- Microsoft.Extensions.Options.ConfigurationExtensions (>= 10.0.11)
- RabbitMQ.Client (>= 7.2.2)
- StackExchange.Redis (>= 3.1.31)
- Stratara.Abstractions (>= 4.0.4)
- Stratara.Contracts (>= 4.0.4)
- Stratara.Mediator (>= 4.0.4)
- Stratara.Sessions (>= 4.0.4)
- Stratara.Shared (>= 4.0.4)
NuGet packages (2)
Showing the top 2 NuGet packages that depend on Stratara.Outbox.RabbitMQ:
| Package | Downloads |
|---|---|
|
Stratara.Infrastructure
Infrastructure glue for the Stratara framework — authorization decorators, configuration providers, and DI composition helpers that wire Mediator, Outbox, Identity, and EF Core into a hosted app. |
|
|
Stratara.EventSourcing.WorkerDefaults
Worker-host wiring composites for the Stratara event-sourced stack. IHostApplicationBuilder extensions (AddBackendServices, AddCommandWorkerServices, AddHeavyCommandWorkerServices, AddEventProjectionWorkerServices, AddEventStreamHashWorkerServices, AddSagaWorkerServices, AddOutboxWorkerServices, and AddCommandServices, AddEventProjectionServices and AddSagaServices without the bus-fed workers) bundle the per-concern DI calls so each worker host opts in with one line. |
GitHub repositories
This package is not used by any popular GitHub repositories.
| Version | Downloads | Last Updated |
|---|---|---|
| 4.2.0 | 46 | 9/18/2026 |
| 4.1.1 | 80 | 9/16/2026 |
| 4.1.0 | 87 | 9/16/2026 |
| 4.0.4 | 625 | 9/14/2026 |
| 4.0.3 | 186 | 9/3/2026 |
| 4.0.2 | 609 | 9/3/2026 |
| 4.0.1 | 222 | 9/2/2026 |
| 4.0.0 | 169 | 8/31/2026 |
| 4.0.0-preview.1 | 76 | 8/31/2026 |
| 3.4.0 | 160 | 8/28/2026 |
| 3.3.0 | 128 | 8/25/2026 |
| 3.2.3 | 141 | 8/22/2026 |
| 3.2.2 | 146 | 8/14/2026 |
| 3.2.1 | 152 | 8/2/2026 |
| 3.2.0 | 142 | 7/18/2026 |
| 3.1.7 | 155 | 7/1/2026 |
| 3.1.6 | 570 | 6/22/2026 |
| 3.1.5 | 152 | 6/22/2026 |
| 3.1.4 | 153 | 6/15/2026 |
| 3.1.3 | 154 | 6/10/2026 |
Three findings from a proof of concept of an alternative execution model, each fixed on the shipped
path. A message a handler cannot take is now redelivered a bounded number of times and then
dead-lettered on both brokers instead of being dropped on one of them; an opt-in closes the window
in which a committed fact could be lost between the commit and its publication; and a version
collision is a concurrency conflict on every supported database provider, not only on PostgreSQL.
Additive on every published surface, with one operator step on RabbitMQ: the worker queues change
name and type, and the old ones are deleted once drained.
### Added
- `Outbox:DurableBundles` (`OutboxOptions.DurableBundles`, default `false`): an event bundle is
written to the outbox table in the transaction that commits its events, published after the
commit, and removed once the bus has accepted it — so a process that ends between the commit and
the publish no longer loses the bundle for every subscription. `IEventBundleOutboxDispatcher`
gains `StoresBundlesWithCommit` and `StoreEventBundleAsync`, and `IOutboxRepository` an
`AddAsync(Guid id, …)` overload, all default-implemented so a consumer's own implementations keep
compiling and keep bus-first. `AddOutboxDispatcher()` now binds the `Outbox` section when the host
carries a configuration. Log event `106_108` records a stored copy the bus accepted but the
framework could not remove. The default path is unchanged; the specification now names its window.
- `IStoreConflictDetector` in `Stratara.Abstractions.EventSourcing`: recognises a database
provider's refusal of a duplicate stream version, so the event source can surface it as a
`ConcurrencyException` on that provider. `AddNpgsqlWriteDbContextFactory<T>()` registers the
PostgreSQL detector and `AddStrataraTestingEventStore<T>()` the SQLite one; detectors accumulate,
so a host on another provider adds its own without displacing the framework's. A host that
registers its write context without `AddNpgsqlWriteDbContextFactory<T>()` gets no detector and
no longer sees a `ConcurrencyException` on a version collision: it switches to that registration,
or registers an `IStoreConflictDetector` of its own that recognises PostgreSQL's SQL state
`23505` in the exception chain (the framework's implementations are not public).
- `MessageRetryOptions` (`Stratara.Abstractions.Messaging`, section `MessageRetry`):
`MaxDeliveryAttempts` (default 3) and `MaxConflictRequeues` (default 100), bound and validated by
`AddMessaging()` and by both `AddAzureServiceBus*` registrations. `MessageRetryPolicy` is the
decision both transports apply. Log event `108_110` and counter `messaging.dead_lettered`
(tags `messaging.topic`, `messaging.subscription`, `reason`) record every dead-lettering; `108_111`
warns when a Service Bus subscription's `MaxDeliveryCount` is below the bounds.
### Changed
- A save now maps and signs its event bundle before the transaction opens, so a save with no
session context — or a signer that fails — fails before anything is committed rather than after
the commit with the events stranded unpublished.
- **RabbitMQ worker subscriptions are quorum queues with a dead-letter queue, under a new name.**
A message whose handler throws is redelivered up to `MaxDeliveryAttempts` times (a concurrency
conflict up to `MaxConflictRequeues` times) and then moved to `<subscription>.dead-letter`; it was
rejected and dropped by the broker before (conflicts were requeued without bound). Because a
classic queue cannot be redeclared as a quorum queue, the worker queue is now
`<subscription>.v2`. **Rollout:** deploy — old and new consumers share the exchange and both
receive every message — then delete the old `<subscription>` queue once it is drained, or it fills
forever. Needs RabbitMQ 3.8+.
- **Azure Service Bus applies the same bounds.** A handler failure is abandoned for redelivery until
`MaxDeliveryAttempts` and then dead-lettered with reason `failure` (it was dead-lettered on the
first failure with the exception type as reason); a conflict is dead-lettered by the framework
past `MaxConflictRequeues` with reason `conflict` (it was left to the broker's `MaxDeliveryCount`).
Set the subscription's `MaxDeliveryCount` at least one above the larger bound.
- `AddAzureServiceBus` and `AddAzureServiceBusWithManagedIdentity` also register a
`ServiceBusAdministrationClient` (try-add) for the advisory limit check.
### Fixed
- The `MediatorCommandWorker` remark said a failing command was dead-lettered; on RabbitMQ it was
dropped. It is now dead-lettered on both brokers, and the remark and the
`BusEnvelopeIntegrityMode.Strict` remark say what happens.
- A duplicate stream version on the SQLite test store (`Stratara.Testing.EntityFrameworkCore`) now
surfaces as `ConcurrencyException`, as it does on PostgreSQL, instead of a bare
`DbUpdateException`. A test that asserted the old exception type needs the new one.