Jochen Kühner
483447e783
Observe packet task failures to prevent unobserved overflow exceptions Server dispatch and session enqueue operations create packet bus items without waiting for delivery. When the pending-message queue overflows, Fail faults the item's completion task, which can later raise UnobservedTaskException even if the application handles the dropped-message notification. Observe the completion task's exception inside MqttPacketBusItem.Fail. This keeps the task faulted and preserves the original exception for existing and future WaitAsync callers, including DeliverApplicationMessageAsync. Add a garbage-collection regression test for failures without a waiter and verify that requesting the task before or after failure preserves the original overflow exception. Re-enable unobserved-exception tracking in the existing overflow integration tests for both drop strategies. Before the fix, the focused run failed the new unobserved-exception test and both enqueue overflow tests. After the fix, all nine focused cases and all 489 tests in the .NET 10 Release test suite pass. Fixes https://github.com/dotnet/MQTTnet/issues/2271
MQTTnet
MQTTnet is a high performance .NET library for MQTT based communication. It provides a MQTT client and a MQTT server (broker) and supports the MQTT protocol up to version 5. It is compatible with mostly any supported .NET Framework version and CPU architecture.
Features
General
- Async support
- TLS support for client and server (but not UWP servers)
- Extensible communication channels (e.g. In-Memory, TCP, TCP+TLS, WS)
- Lightweight (only the low level implementation of MQTT, no overhead)
- Performance optimized (processing ~150.000 messages / second)*
- Uniform API across all supported versions of the MQTT protocol
- Access to internal trace messages
- Unit tested (~636 tests)
- No external dependencies
* Tested on local machine (Intel i7 8700K) with MQTTnet client and server running in the same process using the TCP channel. The app for verification is part of this repository and stored in /Tests/MQTTnet.TestApp.NetCore.
Client
- Communication via TCP (+TLS) or WS (WebSocket) supported
- Included core LowLevelMqttClient with low level functionality
- Also included ManagedMqttClient which maintains the connection and subscriptions automatically. Also application messages are queued and re-scheduled for higher QoS levels automatically.
- Rx support (via another project)
- Compatible with Microsoft Azure IoT Hub
Server (broker)
- List of connected clients available
- Supports connected clients with different protocol versions at the same time
- Able to publish its own messages (no loopback client required)
- Able to receive every message (no loopback client required)
- Extensible client credential validation
- Retained messages are supported including persisting via interface methods (own implementation required)
- WebSockets supported (via ASP.NET Core 2.0, separate nuget)
- A custom message interceptor can be added which allows transforming or extending every received application message
- Validate subscriptions and deny subscribing of certain topics depending on requesting clients
Getting Started
MQTTnet is delivered via NuGet package manager. You can find the packages here: https://www.nuget.org/packages/MQTTnet/
Use these command in the Package Manager console to install MQTTnet manually:
Install-Package MQTTnet
Samples for using MQTTnet are part of this repository. For starters these samples are recommended:
Code of Conduct
This project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behavior in our community. For more information see the .NET Foundation Code of Conduct.
.NET Foundation
This project is supported by the .NET Foundation.