TaskFlow/Engines

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Engine
Engines are what really runs your  and.



An engine takes a  structure (described by patterns) and uses it to decide which   to run and when.

There may be different implementation of engines. Some may be easier to use (ie, require no additional infrastructure setup) and understand, others might require more complicated setup but provide better scalability. The idea and ideal is that deployers/developers of a service that uses taskflow can select an engine that suites their setup best without modifying the code of said service. This allows for that deployer/developer to start off using a simpler implementation and scaling out the service that is powered by taskflow as the service grows. In concept, all engines should implement the same interface to make it easy to replace one engine with another, and provide the same guarantees on how patterns are interpreted -- for example, if an engine runs a linear flow, the tasks should be run one after another in order no matter what type of engine is actually running that linear flow.

Note: engines might have different capabilities/configuration but overall the interface will remain the same and should be transparent to developers and users using taskflow.

Distributed
When you want your applications  and   to be performed in a system that is highly available & resilient to individual failure.

Distributed via RPC

Supports the following:


 * Remote workers that connect over kombu supported transports.
 * Combined with jobboards, provides a high-available engine orchestrator and worker combination.
 * And more...

Traditional
When you want your  and   to just run inside your applications existing framework and still take advantage of the functionality  offered.

Supports the following:


 * Threaded engine using a thread based executor.
 * Threaded engine using a provided eventlet greenthread based executor.
 * Single threaded engine using no threads.
 * And more...