| `minio_api_requests_rejected_auth_total`       | `counter` | Total number of requests rejected for auth failure      | `type,pool_index,server`         |
| `minio_api_requests_rejected_header_total`     | `counter` | Total number of requests rejected for invalid header    | `type,pool_index,server`         |

type MetricType int

const (
	// CounterMT - represents a counter metric.
	CounterMT MetricType = iota
	// GaugeMT - represents a gauge metric.
	GaugeMT
	// HistogramMT - represents a histogram metric.
	HistogramMT
)

func (mt MetricType) String() string {
	switch mt {
	case CounterMT:
		return "counter"
	case GaugeMT:
		return "gauge"
	case HistogramMT:
		return "histogram"
	default:

	sync.RWMutex
}

// Inc increments the api stats counter.
func (stats *HTTPAPIStats) Inc(api string) {
	if stats == nil {
		return
	}
	stats.Lock()
	defer stats.Unlock()
	if stats.apiStats == nil {
		stats.apiStats = make(map[string]int)
	}
	stats.apiStats[api]++
}

// Dec increments the api stats counter.
func (stats *HTTPAPIStats) Dec(api string) {
	if stats == nil {

	// Ignore the uuid sentinel and count the rest.
	for _, etag := range etags {
		if etag == "" {
			continue
		}
		etagOccurrenceMap[etag]++
	}

	maxima = 0 // Counter for remembering max occurrence of elements.
	latest := ""

	// Find the common cardinality from previously collected
	// occurrences of elements.
	for etag, count := range etagOccurrenceMap {
		if count < maxima {