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Lambda Durable Functions Operation Limit Jumps 10x to 30,000!

AWS What's New ★★★★ View Markdown
#aws#serverless#ai

Hi, it's Shii-chan! Today the limits of Lambda durable functions got a big boost!

AWS What's New aws.amazon.com

What was announced?

AWS What's New announced higher limits for AWS Lambda durable functions.

  • Maximum durable operations per execution: from 3,000 to 30,000
  • Maximum checkpoint payload size: from 256 KB to 1 MB

AWS Lambda durable functions help you build resilient multi-step applications and AI workflows that run for up to one year, with built-in checkpointing, automatic retries, and waits that suspend execution without incurring compute charges.

The story so far

Until now, a single execution could handle up to 3,000 operations and checkpoints could hold up to 256 KB. Long loops, long polling, and AI agents with large conversation histories could run into those limits.

What changes

You can safely fit more work into a single execution. The source mentions these uses.

  • Expanding iterative loops
  • Polling for longer time periods
  • Building more complex rollback paths that run when a step fails
  • Agentic applications that reason over thousands of model and tool calls

With 1 MB checkpoints, you can persist larger conversation histories, model responses, and tool outputs directly.

Dive Deep

These operations count toward the limit.

  • Each step attempt
  • Each poll of a wait-for-condition
  • Each branch of a parallel or map operation

With 30,000 operations, you can iterate across thousands of items or poll an external system for weeks without hitting the limit.

1 MB matches the maximum payload size of asynchronous Lambda invocations and of integration services such as Amazon SQS and Amazon EventBridge. That means a workflow can persist a full event from any of them in a single operation.

If you need state larger than 1 MB, the JavaScript and Python SDKs provide a FileSystem serializer. It writes the payload to an Amazon EFS or Amazon S3 Files mount and checkpoints a pointer to it.

The new limits apply in all AWS Regions where Lambda durable functions is available.

Wrap-up

  • Durable operations go from 3,000 to 30,000 per execution
  • Checkpoint payloads go from 256 KB to 1 MB
  • 1 MB matches async Lambda invocation, SQS, and EventBridge payload limits
  • State over 1 MB can be stored by pointer with the FileSystem serializer

This update is for anyone building long-running workflows or AI agents on Lambda!

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