const (
    // SchedulerSubsystem - subsystem name used by scheduler
    SchedulerSubsystem = "scheduler"

    // PrioritizingExtender - prioritizing extender operation label value
    PrioritizingExtender = "prioritizing_extender"
    // Binding - binding operation label value
    Binding = "binding"
)

var (
    SchedulingAlgorithmLatency = metrics.NewHistogram(
        &metrics.HistogramOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "scheduling_algorithm_duration_seconds",
            Help:           "Scheduling algorithm latency in seconds",
            Buckets:        metrics.ExponentialBuckets(0.001, 2, 15),
            StabilityLevel: metrics.ALPHA,
        },
    )
    PreemptionVictims = metrics.NewHistogram(
        &metrics.HistogramOpts{
            Subsystem: SchedulerSubsystem,
            Name:      "preemption_victims",
            Help:      "Number of selected preemption victims",

            Buckets:        metrics.LinearBuckets(5, 5, 10),
            StabilityLevel: metrics.ALPHA,
        })
    PreemptionAttempts = metrics.NewCounter(
        &metrics.CounterOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "preemption_attempts_total",
            Help:           "Total preemption attempts in the cluster till now",
            StabilityLevel: metrics.ALPHA,
        })

    SchedulerGoroutines = metrics.NewGaugeVec(
        &metrics.GaugeOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "scheduler_goroutines",
            Help:           "Number of running goroutines split by the work they do such as binding.",
            StabilityLevel: metrics.ALPHA,
        }, []string{"work"})

    PodSchedulingDuration = metrics.NewHistogramVec(
        &metrics.HistogramOpts{
            Subsystem: SchedulerSubsystem,
            Name:      "pod_scheduling_duration_seconds",
            Help:      "E2e latency for a pod being scheduled which may include multiple scheduling attempts.",

            Buckets:        metrics.ExponentialBuckets(0.01, 2, 20),
            StabilityLevel: metrics.ALPHA,
        },
        []string{"attempts"})

    PodSchedulingAttempts = metrics.NewHistogram(
        &metrics.HistogramOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "pod_scheduling_attempts",
            Help:           "Number of attempts to successfully schedule a pod.",
            Buckets:        metrics.ExponentialBuckets(1, 2, 5),
            StabilityLevel: metrics.ALPHA,
        })

    FrameworkExtensionPointDuration = metrics.NewHistogramVec(
        &metrics.HistogramOpts{
            Subsystem: SchedulerSubsystem,
            Name:      "framework_extension_point_duration_seconds",
            Help:      "Latency for running all plugins of a specific extension point.",

            Buckets:        metrics.ExponentialBuckets(0.0001, 2, 12),
            StabilityLevel: metrics.ALPHA,
        },
        []string{"extension_point", "status", "profile"})

    PluginExecutionDuration = metrics.NewHistogramVec(
        &metrics.HistogramOpts{
            Subsystem: SchedulerSubsystem,
            Name:      "plugin_execution_duration_seconds",
            Help:      "Duration for running a plugin at a specific extension point.",

            Buckets:        metrics.ExponentialBuckets(0.00001, 1.5, 20),
            StabilityLevel: metrics.ALPHA,
        },
        []string{"plugin", "extension_point", "status"})

    SchedulerQueueIncomingPods = metrics.NewCounterVec(
        &metrics.CounterOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "queue_incoming_pods_total",
            Help:           "Number of pods added to scheduling queues by event and queue type.",
            StabilityLevel: metrics.ALPHA,
        }, []string{"queue", "event"})

    PermitWaitDuration = metrics.NewHistogramVec(
        &metrics.HistogramOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "permit_wait_duration_seconds",
            Help:           "Duration of waiting on permit.",
            Buckets:        metrics.ExponentialBuckets(0.001, 2, 15),
            StabilityLevel: metrics.ALPHA,
        },
        []string{"result"})

    CacheSize = metrics.NewGaugeVec(
        &metrics.GaugeOpts{
            Subsystem:      SchedulerSubsystem,
            Name:           "scheduler_cache_size",
            Help:           "Number of nodes, pods, and assumed (bound) pods in the scheduler cache.",
            StabilityLevel: metrics.ALPHA,
        }, []string{"type"})
)

type MetricRecorder interface {
    Inc()
    Dec()
    Clear()
}

type PendingPodsRecorder struct {
    // contains filtered or unexported fields
}