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.

Script
function exponentialRetryPolicy(context) {
    var retries = 3;
    var backoffRate = 2.0;
    var retryInterval = 1000; // 1s
    var maxInterval = 10000; // 10s
    var maxElapsedTime = 10000; // 10s
    var errorCodes = [
        "RequestEntityTooLarge",
        "Throttling",
        "ThrottlingException",
        "RequestLimitExceeded",
        "LimitExceededException",
        "InternalServerError",
        "ServiceUnavailable"
    ];
    return new ExponentialRetryPolicy(errorCodes, retryInterval, maxInterval, maxElapsedTime, retries, backoffRate, context);
}