if d == "" {
		cfg.MaxTimeout = 30 * time.Second
	} else {
		dur, _ := time.ParseDuration(d)
		if dur < time.Second {
			cfg.MaxTimeout = 30 * time.Second
		} else {
			cfg.MaxTimeout = getMaxTimeout(dur)
		}
	}
	return cfg, err
}

func getMaxTimeout(t time.Duration) time.Duration {
	if t > time.Second {
		return t
	}

	if dsecs == "" {
		return defaultExpiry, nil
	}

	d, err := strconv.Atoi(dsecs)
	if err != nil {
		return 0, auth.ErrInvalidDuration
	}

	dur := time.Duration(d) * time.Second

	if dur < minExpiry || dur > maxExpiry {
		return 0, auth.ErrInvalidDuration
	}
	return dur, nil
}

// Lookup returns a new Config by merging the given K/V config
// system with environment variables.

type AccElem struct {
	Total int64
	Size  int64
	N     int64
}

// Add a duration to a single element.
func (a *AccElem) add(dur time.Duration) {
	if dur < 0 {
		dur = 0
	}
	a.Total += int64(dur)
	a.N++
}

// Merge b into a.
func (a *AccElem) merge(b AccElem) {
	a.N += b.N
	a.Total += b.Total
	a.Size += b.Size
}

// Avg returns average time spent.

// previous results
func (dt *dynamicTimeout) adjust(entries [dynamicTimeoutLogSize]time.Duration) {
	failures, max := 0, time.Duration(0)
	for _, dur := range entries[:] {
		if dur == maxDuration {
			failures++
		} else if dur > max {
			max = dur
		}
	}

	failPct := float64(failures) / float64(len(entries))

	if failPct > dynamicTimeoutIncreaseThresholdPct {