Stratara.Outbox.RabbitMQ
4.4.2
Prefix Reserved
dotnet add package Stratara.Outbox.RabbitMQ --version 4.4.2
NuGet\Install-Package Stratara.Outbox.RabbitMQ -Version 4.4.2
<PackageReference Include="Stratara.Outbox.RabbitMQ" Version="4.4.2" />
<PackageVersion Include="Stratara.Outbox.RabbitMQ" Version="4.4.2" />
<PackageReference Include="Stratara.Outbox.RabbitMQ" />
paket add Stratara.Outbox.RabbitMQ --version 4.4.2
#r "nuget: Stratara.Outbox.RabbitMQ, 4.4.2"
#:package Stratara.Outbox.RabbitMQ@4.4.2
#addin nuget:?package=Stratara.Outbox.RabbitMQ&version=4.4.2
#tool nuget:?package=Stratara.Outbox.RabbitMQ&version=4.4.2
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 ProjectionReplayState that coordinates dispatch skip during projection replay — shared over Redis where a connection is registered, held in process otherwise. 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table on bus failure), EventBundleOutboxDispatcher (same for EventBundle), OutboxWorker (hosted service that retries unpublished outbox rows on a polling interval), NullOutboxLock + RedisOutboxLock (IOutboxLock implementations — default no-op for single-instance deployments, Redis-leased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. A worker subscription is a quorum queue <subscription>.v2 with <subscription>.dead-letter beside it; a message a handler cannot take is redelivered under MessageRetryOptions and then dead-lettered. A subscription holds at most Messaging:PrefetchCount messages (default 16), and the host waits for a stopping subscription's running handler to settle before it counts as stopped — within the host's shutdown timeout; twenty seconds for a subscription stopped on its own. 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 (concrete IProjectionReplayState, Redis-backed where a connection is registered, in process otherwise; 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() reads the options from the ProjectionReplay section of the host's configuration; services.Configure<ProjectionReplayOptions>(...) after that call takes precedence. A lease of zero or less fails the host at start. 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(only used when a connection is registered: shared 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 (>= 4.4.2)
- Stratara.Contracts (>= 4.4.2)
- Stratara.Mediator (>= 4.4.2)
- Stratara.Sessions (>= 4.4.2)
- Stratara.Shared (>= 4.4.2)
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 |
|---|---|---|
| 4.4.2 | 71 | 10/2/2026 |
| 4.4.1 | 356 | 9/29/2026 |
| 4.4.0 | 153 | 9/27/2026 |
| 4.3.1 | 143 | 9/25/2026 |
| 4.3.0 | 313 | 9/23/2026 |
| 4.2.0 | 182 | 9/18/2026 |
| 4.1.1 | 111 | 9/16/2026 |
| 4.1.0 | 115 | 9/16/2026 |
| 4.0.4 | 950 | 9/14/2026 |
| 4.0.3 | 192 | 9/3/2026 |
| 4.0.2 | 615 | 9/3/2026 |
| 4.0.1 | 304 | 9/2/2026 |
| 4.0.0 | 175 | 8/31/2026 |
| 4.0.0-preview.1 | 83 | 8/31/2026 |
| 3.4.0 | 164 | 8/28/2026 |
| 3.3.0 | 135 | 8/25/2026 |
| 3.2.3 | 146 | 8/22/2026 |
| 3.2.2 | 149 | 8/14/2026 |
| 3.2.1 | 160 | 8/2/2026 |
| 3.2.0 | 148 | 7/18/2026 |
A release about a flag that cost too much. Every host sharing the replay coordination state over Redis
asked Redis, with a blocking round trip on the calling thread, whether a replay was active — and the
Orleans execution model asked on every hot path, eight to ten times per command on a host with three
projections, inside grain turns. On a two-core host that was enough to starve the thread pool and time
the Redis connection out, surfacing as failed catch-ups, lagging read models and failed grain
registrations although no replay ever ran. The answer now comes from memory. No migration is needed;
one optional setting is new.
### Fixed
- **No path waits on Redis to learn whether a replay is active.** The Redis-backed replay state answers
`IsReplayActive` from a field. A change made in the host itself is seen there at once; a change made
elsewhere — a replay that began or ended in another host, or a marking that lapsed — is announced over
a channel beside the replay-request channel and seen within its latency, and every host re-reads the
marking every `ProjectionReplay:RefreshSeconds` regardless, as the safety net for a lost announcement.
The Orleans execution model's command dispatcher, bundle dispatcher, store readers and drain, and the
bus dispatchers, make no Redis call for it any more. Nothing changes for a host without Redis, whose
state was in process already, nor for a host that registers its own `IProjectionReplayState`.
### Added
- **`ProjectionReplayOptions.RefreshSeconds`** (default 5), read from the `ProjectionReplay` section
like the lease. It bounds how long a host answers from a replay marking that changed elsewhere where the
announcement was lost. Refused when the host starts at zero or below, and at or above
`LeaseSeconds`, with an `OptionsValidationException` naming `ProjectionReplay:RefreshSeconds`.
- **Log events `104_015` to `104_018`.** A host that cannot refresh the replay marking from Redis says
so once at Warning (`104_015`) and keeps its last answer; `104_016` at Information says it reads the
marking again. A host that cannot subscribe to the marking's announcements says so once at Warning
(`104_017`), sees a change on the refresh period only, and `104_018` says it is subscribed again.
### Changed
- **A host that cannot reach Redis keeps its last answer about the replay.** Before, every dispatch and
every catch-up on such a host failed with the connection's exception. Now they proceed on what the host
last learned — initially that no replay is active — and the loss is logged once. The replay stays
correct regardless: on the Orleans execution model the readers are paused by the rebuild and the
replay themselves, and apply the store from the beginning once more when the replay ends.
- **Rolling upgrade.** A host on a release before this one announces nothing when it starts or ends a
replay, so a host on this release sees that replay at the refresh period rather than at once. The
marking, its key and its lease are unchanged, so the two releases share one replay state.