When requests to Step Function fail, Workflow Service performs exponential backoff retries to notify Step Function service. Number of retries = 3 The total duration of all attempts doesn't exceed 10 seconds, the processing must not exceed the message visibility timeout.

Script
"Retry": [
  {
    "ErrorEquals": [
      "States.ALL"
    ],
    "IntervalSeconds": 1,
    "MaxAttempts": 3,
    "BackoffRate": 2
  }
]