For Step Function Map state in Distributed mode does the minimum concurrent executions have to be 40?

Question

I am reading the documentation here https://docs.aws.amazon.com/step-functions/latest/dg/concepts-asl-use-map-state-distributed.html and it says "You need a concurrency of more than 40 parallel iterations."

What if in my workflow there are some instances where I need more than 40 but not 100% of the time?

Mikel Del Tio · Answer

Hi,

40 is the limit of concurrent interactions supported by the map state in inline mode, hence the mention.

Thus, [AWS recommends](https://docs.aws.amazon.com/step-functions/latest/dg/concepts-map-process-modes.html) the **Inline mode** if your workflow's execution history won't exceed 25,000 entries, or if you don't require more than 40 concurrent iterations, and the **Distributed mode** when it is required to exceed those limits or the size of your dataset exceeds 256 KB.

You can take a look at the difference between them in the [following link](https://docs.aws.amazon.com/step-functions/latest/dg/concepts-inline-vs-distributed-map.html), but remember that Distributed mode is not supported for Express Step Functions.

For Step Function Map state in Distributed mode does the minimum concurrent executions have to be 40?

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