Basic Fault Tolerance Patterns Questions

# Pseudocode (python-style)
def http_request_with_retries(req, max_retries=4, base_backoff=0.5):
    attempt = 0
    while attempt <= max_retries:
        state = circuit_breaker.get_state()  # CLOSED, OPEN, HALF_OPEN
        if state == "OPEN":
            metrics.increment("client.fast_fail")
            return Failure("circuit_open")
        # allow attempt if CLOSED or HALF_OPEN
        start = now()
        resp = http_client.send(req, timeout=compute_timeout(attempt))
        latency = now() - start
        metrics.record("client.request.latency", latency)
        if resp.is_success():
            circuit_breaker.on_success()
            metrics.increment("client.success")
            return resp
        else:
            metrics.increment("client.error")
            circuit_breaker.on_failure()
            attempt += 1
            if attempt > max_retries:
                metrics.increment("client.retry_exhausted")
                return Failure("retries_exhausted")
            # decide backoff: if breaker just moved to OPEN, fast-fail next loop
            backoff = jittered_backoff(base_backoff * (2 ** (attempt - 1)))
            sleep(backoff)