Why does my AWS step function time out after 5 minutes?

Question

I have an AWS step function that times out after 5 minutes and I cannot come up with a reason why this would happen. This is my state machine definition:

{
  "Comment": "This state machine will fire off a reminder lambda for an outage status update after a delay",
  "StartAt": "Wait",
  "States": {
    "Wait": {
      "Type": "Wait",
      "Comment": "Wait for an hour",
      "Seconds": 3600,
      "Next": "Send Reminder"
    },
    "Send Reminder": {
      "Type": "Task",
      "Comment": "Send a reminder in Slack for a status update",
      "Resource": "arn:aws:states:::lambda:invoke",
      "Parameters": {
        "Payload.$": "$",
        "FunctionName": "${FunctionArn}"
      },
      "End": true
    }
  }
}

Whenever the state machine is kicked off, it enters the Wait state, but after 5 minutes in that state, the entire machine times out. As you can see in the logs, it never reaches the Lambda function to execute it.

As I understand it, if I don't put a timeout on the state machine, it should not time out by itself until 1 year after starting. I've tried adding "TimeoutSeconds": 7200 to the machine definition to see if explicitly setting a timeout would help, but that doesn't change the outcome.

What could cause this?

Answer 1

You probably created an Express Workflow, they have a timeout of 5 minutes - see: Standard vs. Express Workflows.

Use a standard Workflow if you want a step function that can run for a longer time. You could use the TimeoutSeconds parameter on the highest level of the state machine definition to limit the runtime (see State Machine Structure).