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.

public void retry() {
    final int maxRetries = 3;
    int attempts = 0;
    int sleepTime = 100;
    Exception lastException = null;
    do {
      attempts++;
      try {
        // perform request
      } catch (Exception e) {
        lastException = e;
        try {
          Thread.sleep(sleepTime);
        } catch (InterruptedException ie) {
          break;
        }
        sleepTime *= 2;
      }
    } while (attempts < maxRetries && sleepTime < 10000);
    if (attempts == maxRetries) {
      throw lastException;
    }
  }