When requests to Step Function fail, Workflow Service performs exponential backoff retries to notify Step Function service.

public class ExponentialBackoff {
    private static final int MAX_RETRIES = 5;
    private static final long INITIAL_DELAY = 500;
    private static final long MAX_DELAY = 15000;

    public static void main(String[] args) {
        int currentRetries = 0;
        long delay = INITIAL_DELAY;
        while (currentRetries < MAX_RETRIES) {
            System.out.println("currentRetries: " + currentRetries + " ; delay: " + delay);
            currentRetries++;
            delay *= 2;
            if (delay > MAX_DELAY) {
                delay = MAX_DELAY;
            }
        }
    }
}