Skip to main content

AWS Step Functions

AWS Step Functions FAQs

Overview

Open all

    AWS Step Functions is a fully managed service that makes it easier to coordinate the components of distributed applications and microservices using visual workflows. Building applications from individual components that each perform a discrete function helps you scale more easily and change applications more quickly.

    Step Functions is a reliable way to coordinate components and step through the functions of your application. Step Functions provides a graphical console to arrange and visualize the components of your application as a series of steps. This makes it easier to build and run multi-step applications.

    Step Functions automatically triggers and tracks each step and retries when there are errors, so your application executes in order and as expected. Step Functions logs the state of each step, so when things do go wrong, you can diagnose and debug problems more quickly. You can change and add steps without even writing code, so you can more easily evolve your application and innovate faster.

    Breaking an application into service components (or steps) ensures that the failure of one component does not bring the whole system down. Each component scales independently and that component may be updated without requiring the entire system to be redeployed after each change.

    The coordination of service components involves managing execution dependencies and scheduling, and concurrency in accordance with the logical flow of the application. In such an application, you can use service orchestration to do this and to handle failures.

    Step Functions helps with any computational problem or business process that can be subdivided into a series of steps. It’s also useful for creating end-to-end workflows to manage jobs with interdependencies. Common use cases include:

    • Data processing: consolidate data from multiple databases into unified reports, refine and reduce large data sets into useful formats, iterate and process millions of files in an Amazon Simple Storage Service (S3) bucket with high concurrency workflows, or coordinate multi-step analytics and machine learning workflows
    • Building serverless generative AI applications: leverage Step Functions for orchestrating interactions with Amazon Bedrock’s Foundation Models, prompt chaining, fine-tuning, and enriching with capabilities from over 220 AWS services
    • DevOps and IT automation: build tools for continuous integration and continuous deployment, or create event-driven applications that automatically respond to changes in infrastructure
    • E-commerce: automate mission-critical business processes, such as order fulfillment and inventory tracking
    • Web applications: implement robust user registration processes and sign-on authentication

    For more details, explore AWS Step Functions use cases and customer testimonials.

    When you use Step Functions, you define state machines that describe your workflow as a series of steps, their relationships, and their inputs and outputs. State machines contain a number of states, each of which represents a step in a workflow diagram.

    States can perform work, make choices, pass parameters, initiate parallel execution, manage timeouts, or terminate your workflow with a success or failure.

    The visual console automatically graphs each state in the order of execution, making it easier to design multi-step applications. The console highlights the real-time status of each step and provides a detailed history of every execution.

    For more information, see How Step Functions Works in the Step Functions developer guide.

    You can orchestrate any AWS service using service integrations or any self-managed application component using Activity Tasks.

    Service integrations help you construct calls to AWS services and include the response in your workflow. AWS–SDK service integrations help you invoke one of over 9,000 AWS API actions from over 200 services directly from your workflow.

    Optimized service integrations further simplify use of common services such as AWS Lambda, Amazon Elastic Container Service (ECS), AWS Glue, or Amazon EMR with capabilities including IAM policy generation and the RunAJob pattern that will automatically wait for completion of asynchronous jobs.

    Activity Tasks incorporate integration with activity works that you run in a location of your choice, including in Amazon Elastic Compute Cloud (EC2), in Amazon ECS, on a mobile device, or on an on-premises server. The activity worker polls Step Functions for work, takes any inputs from Step Functions, performs the work using your code, and returns results. Since activity workers request work, it is easier to use workers that are deployed behind a firewall.

    A Step Functions state machine can contain combinations of service integrations and Activity Tasks. Step Functions applications can also combine activity workers running in a data center with service tasks that run in the cloud. The workers in the data center continue to run as usual, along with any cloud-based service tasks.