// InstanceErrs is a measure of the number of errors for processing instance config.
	InstanceErrs = monitoring.NewGauge(
		"mixer/config/instance_config_errors_total",
		"The number of errors encountered during processing of the instance configuration.",
	)

	// RulesTotal is a measure of the number of known rules.
	RulesTotal = monitoring.NewGauge(
		"mixer/config/rule_configs_total",
		"The number of known rules in the current config.",
	)

	)

	// pilot_total_xds_rejects should be used instead. This is for backwards compatibility
	cdsReject = monitoring.NewGauge(
		"pilot_xds_cds_reject",
		"Pilot rejected CDS configs.",
	)

	// pilot_total_xds_rejects should be used instead. This is for backwards compatibility
	edsReject = monitoring.NewGauge(
		"pilot_xds_eds_reject",
		"Pilot rejected EDS.",
	)

)

const (
	namespace = "kube_apiserver"
	subsystem = "nodeport_allocator"
)

var (
	// nodePortAllocated indicates the amount of ports allocated by NodePort Service.
	nodePortAllocated = metrics.NewGauge(
		&metrics.GaugeOpts{
			Namespace:      namespace,
			Subsystem:      subsystem,
			Name:           "allocated_ports",
			Help:           "Gauge measuring the number of allocated NodePorts for Services",

	OrphanPodCleanedVolumesErrors = metrics.NewGauge(
		&metrics.GaugeOpts{
			Subsystem:      KubeletSubsystem,
			Name:           orphanPodCleanedVolumesErrorsKey,
			Help:           "The number of orphaned Pods whose volumes failed to be cleaned in the last periodic sweep.",
			StabilityLevel: metrics.ALPHA,
		},
	)

	NodeStartupPreKubeletDuration = metrics.NewGauge(
		&metrics.GaugeOpts{

			StabilityLevel: metrics.ALPHA,
		},
	)

	// SyncProxyRulesLastTimestamp is the timestamp proxy rules were last
	// successfully synced.
	SyncProxyRulesLastTimestamp = metrics.NewGauge(
		&metrics.GaugeOpts{
			Subsystem:      kubeProxySubsystem,
			Name:           "sync_proxy_rules_last_timestamp_seconds",
			Help:           "The last time proxy rules were successfully synced",

	)

	successCounts = monitoring.NewSum(
		"citadel_server_success_cert_issuance_count",
		"The number of certificates issuances that have succeeded.",
	)

	rootCertExpiryTimestamp = monitoring.NewGauge(
		"citadel_server_root_cert_expiry_timestamp",
		"The unix timestamp, in seconds, when Citadel root cert will expire. "+
			"A negative time indicates the cert is expired.",
	)

	cniInstalls = monitoring.NewSum(
		"istio_cni_installs_total",
		"Total number of CNI plugins installed by the Istio CNI installer",
	)

	installReady = monitoring.NewGauge(
		"istio_cni_install_ready",
		"Whether the CNI plugin installation is ready or not",
	)

	})
	o, dm := createOptions(name, description, opts...)
	if dm != nil {
		return dm
	}
	return newCounter(o)
}

// NewGauge creates a new Gauge Metric. That means that data collected by the new
// Metric will export only the last recorded value.
func NewGauge(name, description string, opts ...Options) Metric {
	knownMetrics.register(MetricDefinition{
		Name:        name,
		Type:        "LastValue",

	versionTag = monitoring.CreateLabel("version")

	monServices = monitoring.NewGauge(
		"pilot_services",
		"Total services known to pilot.",
	)

	// TODO: Update all the resource stats in separate routine
	// virtual services, destination rules, gateways, etc.
	xdsClients = monitoring.NewGauge(
		"pilot_xds",
		"Number of endpoints connected to this pilot using XDS.",
	)

// See the License for the specific language governing permissions and
// limitations under the License.

package monitoring_test

import "istio.io/istio/pkg/monitoring"

var pushLatency = monitoring.NewGauge(
	"push_latency_seconds",
	"Duration, measured in seconds, of the last push",
	monitoring.WithUnit(monitoring.Seconds),
)

func ExampleNewGauge() {