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.

int retryCount = 0;
while (retryCount <= 3) {
  try {
    // Attempt to send request to Step Function
    break;
  } catch (SdkClientException e) {
    retryCount++;
    final int pause = (int) (Math.pow(2, retryCount) * 100);
    Thread.sleep(pause);
    // Re-throw if retryCount is 3
    if (retryCount == 3) {
      throw e;
    }
  }
}