Simple Workflow Essentials:
SWF is a fully-managed "work flow" service provided by AWS.
A SWF workflow allows an architecture/developer to implement distributed, synchronous applications as a work flow.
A workflow coordinates and manages the execution of activities that can be run asynchronously across multiple computing devices.
SWF has consistent execution.
Guarantees the order in which tasks are executed.
There are no duplicate tasks.
The SWF service is primarily an API which an application can integrate it's work flow service into. This allows the service to be used by non-AWS services, such as an on-premise data center.
A workflow execution can last up to 1 year.
Components of SWF
- Workflow: A sequence of steps required to perform a specific task.
- A workflow is also commonly referred to as a decider.
- Activities: A single step (or unit of work) in the workflow.
- Tasks: What interacts with the "workers" that are part of a workflow.
- Activity task - Tells the worker to perform a function.
- Decision task - Tells the decider the state of the work flow execution, which allows the decider to determine the next activity to be performed.
- Worker: Responsible for receiving a task and taking action on it.
- Can be any type of component such as an EC2 instance, or even a person.