Overview of crumble

To create an event-driven job, unit of work, function, or whatever you want to call it, is extremely simple. Just by marking a method with the [Crumb] attribute. This registers the crumb to crumble runtime, which can later be triggered by an event. However, if a specific trigger must be explicitly specified, there are two main options. First, an in-code approach using corresponding attributes [TimeEvent], [VolumeEvent] or [MessageEvent].

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Units of work (cumbs) and three events: time, data, and message.

The runtime supports three triggers, no more are needed. [TimeEvent] based trigger that can follow a schedule defined by a CRON expression and be combined with a time zone. [VolumeEvent] represents a trigger of an event in a data source or file source. [MessageEvent] is an asynchronous event with or without a payload on the input or output side.

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The most flexible way is to connect your crumble orchestration to the 2S platform and make the trigger fully configurable from within, without needing to change code or redeploy your application when a trigger is modified, added, or removed.

Simplest examples of crumbs

A time scheduled:

[Crumb, TimeEvent("42 */2 * * *")]
public Task DoScheduledWork(DateTimeOffset startTime)
{
    // your business logic lies here
}

The concept of volume and its triggers serves as an abstraction of a data source. A virtual source of entities. It is optimized to work with a large number of entities, which can be structured in a tree-shaped folder structure. Sources, such as files, Azure storage, PostgreSQL entities, CosmosDB documents, and similar, can be connected to your crumbs.

[Crumb, VolumeEvent("folder/entityName")]
public Task DoWorkOnEntity(string path)
{
    // your business logic lies here
}

Message triggers represent async communication on any of the supported channels. For example, Azure storage queues, message buses, EventHub, Kafka, and much more.

[Crumb, MessageEvent]
public Task DoMessageWork(IMessageModel message)
{
    // your business logic lies here
}

When you put together your crumbs orchestration, you can take it into your application. It can be a serverless architecture built on Azure Applications, a pure distributed system powered by Orleans, or a monolithic application on the .NET platform. The only thing you have to do is register it with your IServiceCollection by calling .AddCrumbs() for every library with crumbs. The generation for different architectures can be achieved by referencing the corresponding source generator package.