var (
    SyncProxyRulesLatency = metrics.NewHistogram(
        &metrics.HistogramOpts{
            Subsystem:      kubeProxySubsystem,
            Name:           "sync_proxy_rules_duration_seconds",
            Help:           "SyncProxyRules latency in seconds",
            Buckets:        metrics.ExponentialBuckets(0.001, 2, 15),
            StabilityLevel: metrics.ALPHA,
        },
    )

    DeprecatedSyncProxyRulesLatency = metrics.NewHistogram(
        &metrics.HistogramOpts{
            Subsystem:         kubeProxySubsystem,
            Name:              "sync_proxy_rules_latency_microseconds",
            Help:              "SyncProxyRules latency in microseconds",
            Buckets:           metrics.ExponentialBuckets(1000, 2, 15),
            StabilityLevel:    metrics.ALPHA,
            DeprecatedVersion: "1.14.0",
        },
    )

    // 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",
            StabilityLevel: metrics.ALPHA,
        },
    )
)