Step Functions is a serverless orchestration service that integrates Lambda functions and other AWS services to build workflows modeled as a state machine in JSON.
The max execution time is 1 year with the ability to implement human interaction and approval. Strangely, Step Functions does NOT integrate with Mechanical Turk.
Step Function has several optimized integrations with Lambda, Batch, ECS, DynamoDB, SNS/SQS, EMR/Glue/SageMaker, and the SDK and can be invoked using the StartExecution call from SDK, API, Lambda), or from API Gateway, EventBridge, CodePipeline, and StepFunctions.
Task types
There are 4 types of Tasks:
- Lambda tasks - invoke a function
- Activity task - set up an activity worker then distribute a task via call back once active
- Service task - connection to a supported AWS service
- Wait task - wait for a duration or until a timestamp.
Workflow types
There are two types of workflows:
| Standard | Express | |
|---|---|---|
| Max duration | 1 year | 5 minutes |
| Execution start per second | 2000 | >100k |
| Transition rate per second | 4000 | nearly unlimited |
| Price | per state transition | executions, duration, memory |
| Execution Semantics | exactly once | at least once (asynchronous); at most once(synchronous) |
Error handling
You can enable error handling, retries (retry interval, MaxAttempts, backoffRate) and add alerting to State Machines.