failureThreshold: 3
```

## Cluster probe

### Cluster-writeable probe

The reply is '200 OK' if cluster has write quorum if not it returns '503 Service Unavailable'.

```
curl http://minio1:9001/minio/health/cluster
HTTP/1.1 503 Service Unavailable
Accept-Ranges: bytes
Content-Length: 0
Server: MinIO
Vary: Origin
X-Amz-Bucket-Region: us-east-1
X-Minio-Write-Quorum: 3
X-Amz-Request-Id: 16239D6AB80EBECF

	}

	for _, signer := range hmacSigners {
		if string(alg) == signer.Name {
			return signer, nil
		}
	}

	return nil, jwtgo.NewValidationError(fmt.Sprintf("signing method (%s) is unavailable.", string(alg)),
		jwtgo.ValidationErrorUnverifiable)
}

// ParseWithClaims - parse the token string, valid methods.
func ParseWithClaims(tokenStr string, claims *MapClaims, fn func(*MapClaims) ([]byte, error)) error {

			listenErrCallback(srv.Addrs[i], listenErrs[i])
		} else {
			interfaceFound = true
		}
	}
	if !interfaceFound {
		return nil, errors.New("no available interface found")
	}

	// Wrap given handler to do additional
	// * return 503 (service unavailable) if the server in shutdown.
	wrappedHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// If server is in shutdown.

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrBusy: {
		Code:           "ServerBusy",
		Description:    "The service is unavailable. Please retry.",
		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrUnauthorizedAccess: {
		Code:           "UnauthorizedAccess",
		Description:    "You are not authorized to perform this operation",

	"github.com/minio/minio/internal/kms"
)

const unavailable = "offline"

// ClusterCheckHandler returns if the server is ready for requests.
func ClusterCheckHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "ClusterCheckHandler")

	objLayer := newObjectLayerFn()
	if objLayer == nil {
		w.Header().Set(xhttp.MinIOServerStatus, unavailable)
		writeResponse(w, http.StatusServiceUnavailable, nil, mimeNone)

						logger.Info("   - Drive: %s", disk.String())
					}
				})
				logger.Info(color.Yellow("WARNING:")+" Host %v has more than %v drives of set. "+
					"A host failure will result in data becoming unavailable.", host, wantAtMost)
			}
		}
	}

	// Save formats `format.json` across all disks.
	if err := saveFormatErasureAll(ctx, storageDisks, formats); err != nil {
		return nil, err
	}

)

const (
	memTotal     = "total"
	memUsed      = "used"
	memFree      = "free"
	memBuffers   = "buffers"
	memCache     = "cache"
	memUsedPerc  = "used_perc"
	memShared    = "shared"
	memAvailable = "available"
)

var (
	memTotalMD     = NewGaugeMD(memTotal, "Total memory on the node")
	memUsedMD      = NewGaugeMD(memUsed, "Used memory on the node")

```

> NOTE: A zero value of `requests_max` means MinIO will automatically calculate requests based on available RAM size and that is the default behavior.

### Configuring connection (wait) deadline

This value works in conjunction with max connection setting, setting this value allows for long waiting requests to quickly time out when there is no slot available to perform the request.

type poolAvailableSpace struct {
	Index      int
	Available  uint64 // in bytes
	MaxUsedPct int    // Used disk percentage of most filled disk, rounded down.
}

// TotalAvailable - total available space
func (p serverPoolsAvailableSpace) TotalAvailable() uint64 {
	total := uint64(0)
	for _, z := range p {
		total += z.Available
	}
	return total
}

	return len(list.targets) == 0
}

// List - returns available target IDs.
func (list *TargetList) List(region string) []ARN {
	list.RLock()
	defer list.RUnlock()

	keys := make([]ARN, 0, len(list.targets))
	for k := range list.targets {
		keys = append(keys, k.ToARN(region))
	}

	return keys
}

// TargetMap - returns available targets.
func (list *TargetList) TargetMap() map[TargetID]Target {