SWF

Simple Workflow Service

Amazon SFW is a web service that makes it easy to coordinate work across distributed application components. SWF enables application components. SWF enables applications for a range of use cases, including media processing, web application backends, business process workflows, and analytics pipelines, to be designed as a coordination of tasks.

Tasks represent invocations of various processing steps in an application which can be performed by executable code, web service calls, human actions and scripts.

SWF Actors

• Workflow starters - an application that can initiate (start) a workflow.

• Deciders - control the flow of activity tasks in a workflow execution. If something has finished (or failed) in a workflow, a decider decides what to do next.

• Activity workers - carry out the activity tasks.

SQS vs SWF

• SQS has a retention period of up to 14 days, with SWF workflow executions can last up to 1 year.

• SWF represents a task-oriented API, whereas SQS offers a message-oriented API.

• SWF ensures that a task is assigned only once and is never duplicated. With SQS, you need to handle duplicate messages.

• SWF keeps track of all the tasks and events in an application. With SQS, you need to implement your own application-level tracking, especially if your application uses multiple queues.