| title | summary | reviewed | component | related | ||
|---|---|---|---|---|---|---|
Hangfire Usage |
Using of Hangfire to send messages from within an NServiceBus endpoint. |
2017-09-20 |
Core |
|
This sample illustrates the use of Hangfire to send messages from within an NServiceBus endpoint.
Hangfire - An easy way to perform background processing in .NET and .NET Core applications. Hangfire is an open-source framework that helps you to create, process and manage your background jobs.
include: scheduler-drawbacks
- Start both the Scheduler and Receiver projects.
- At startup Scheduler will schedule sending a message to Receiver every minute.
- Receiver will handle the message.
This is a helper class used to make the NServiceBus IEndpointInstance available inside Hangfire jobs. In this sample it is implemented as a static property.
snippet: EndpointInstance
Hangfire also supports Dependency Injection (DI) via the JobActivator API for more advanced scenarios.
The endpoint is started and the IEndpointInstance is stored in the static endpoint helper.
This sample uses in-memory storage for the jobs. Production scenarios should use more robust alternatives: SqlServer, Msmq or Redis.
Hangfire calls their scheduler a BackgroundJobServer. It is started automatically when an instance of the BackgroundJobServer class is instantiated.
snippet: Configuration
This sample passes in an expression pointing to the static Run method in SendMessageJob.
snippet: SendMessageJob
Note that the EndpointHelper is used by the job to get access to the IEndpointInstance .
Hangfire will accept any lambda expression as a job definition.
The expression is serialized, stored and scheduled for execution by the BackgroundJobServer in Hangfire.
The schedule is set using Cron syntax through the Cron class. In this sample the job gets scheduled to run every minute.
snippet: scheduleJob
The Hangfire server should be disposed when the endpoint is shut down.
snippet: shutdown
The Hangfire scheduler implements the IDisposable interface. For cleanup purposes, keep a reference to the scheduler instance and call Dispose() at shutdown. Alternatively, use dependency injection and let cleanup be automatically be managed.
Hangfire uses LibLog. Since LibLog supports the detection and utilization of Serilog, this sample uses the NServiceBus Serilog integration
snippet: serilog
LibLog supports many other common logging libraries. Hangfire can also be configured to use a custom logger. See also Adding logging in Hangfire.
Note that in this sample an instance of the Hangfire scheduler is configured to run in every endpoint's instance. If an endpoint is scaled out then the configured jobs will be executed by each of the running instances. A persistent job storage can help to manage the Hangfire scheduler shared state, including jobs, triggers, calendars, etc.