Managing Lambda workflows and events - AWS Lambda
Orchestrating workflows with Step FunctionsManaging events with EventBridge and EventBridge Scheduler

Managing Lambda workflows and events

When building serverless applications with Lambda, you often need ways to orchestrate function execution and handle events. AWS provides two key services that help coordinate Lambda functions:

  • AWS Step Functions for workflow orchestration

  • Amazon EventBridge Scheduler and Amazon EventBridge for event management

Additionally, you can integrate Step Functions and EventBridge together in your applications. For example, you might use EventBridge Scheduler to trigger Step Functions workflows when specific events occur, or configure Step Functions workflows to publish events to EventBridge Scheduler at defined execution points. The following topics in this section provide more information on how you can use these services.

Orchestrating workflows with Step Functions

AWS Step Functions is a workflow orchestration service that helps you coordinate multiple Lambda functions and other AWS services into structured workflows. These workflows can maintain state, handle errors with sophisticated retry mechanisms, and process data at scale.

Step Functions offers two types of workflows to meet different orchestration needs:

Standard workflows

Ideal for long-running, auditable workflows that require exactly-once execution semantics. Standard workflows can run for up to one year, provide detailed execution history, and support visual debugging. They are suitable for processes like order fulfillment, data processing pipelines, or multi-step analytics jobs.

Express workflows

Designed for high-event-rate, short-duration workloads with at-least-once execution semantics. Express workflows can run for up to five minutes and are ideal for high-volume event processing, streaming data transformations, or IoT data ingestion scenarios. They offer higher throughput and potentially lower cost compared to Standard workflows.

Note

For more information on Step Functions workflow types, see Choosing workflow type in Step Functions.

Within these workflows, Step Functions provides two types of Map states for parallel processing:

Inline Map

Processes items from a JSON array within the execution history of the parent workflow. Inline Map supports up to 40 concurrent iterations and is suitable for smaller datasets or when you need to keep all processing within a single execution. For more information, see Using Map state in Inline mode.

Distributed Map

Enables processing of large-scale parallel workloads by iterating over datasets that exceed 256 KiB or require more than 40 concurrent iterations. With support for up to 10,000 parallel child workflow executions, Distributed Map excels at processing semi-structured data stored in Amazon S3, such as JSON or CSV files, making it ideal for batch processing and ETL operations. For more information, see Using Map state in Distributed mode.

By combining these workflow types and Map states, Step Functions provides a flexible and powerful toolset for orchestrating complex serverless applications, from small-scale operations to large-scale data processing pipelines.

To get started with using Lambda with Step Functions, see Orchestrating Lambda functions with Step Functions.

Managing events with EventBridge and EventBridge Scheduler

Amazon EventBridge is an event bus service that helps you build event-driven architectures. It routes events between AWS services, integrated applications, and software as a service (SaaS) applications. EventBridge Scheduler is a serverless scheduler that enables you to create, run, and manage tasks from one central service, allowing you to invoke Lambda functions on a schedule using cron and rate expressions, or configure one-time invocations.

Amazon EventBridge and EventBridge Scheduler help you build event-driven architectures with Lambda. EventBridge routes events between AWS services, integrated applications, and SaaS applications, while EventBridge Scheduler provides specific scheduling capabilities for invoking Lambda functions on a recurring or one-time basis.

These services provide several key capabilities for working with Lambda functions:

  • Create rules that match and route events to Lambda functions using EventBridge

  • Set up recurring function invocations using cron and rate expressions with EventBridge Scheduler

  • Configure one-time function invocations at specific dates and times

  • Define flexible time windows and retry policies for scheduled invocations

For more information, see Invoke a Lambda function on a schedule.