metric

var (
	ConnMaxOpen = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_max_open",
			Help: "The maximum number of open connections to the database.",
		},
		[]string{sqlInstance},
	)
	ConnInUse = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_in_use",
			Help: "The number of connections currently in use",
		},
		[]string{sqlInstance},
	)
	ConnIdle = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_idle",
			Help: "The number of idle connections",
		},
		[]string{sqlInstance},
	)
	ConnWait = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_wait",
			Help: "The total number of connections wait for",
		},
		[]string{sqlInstance},
	)
	ConnIdleClosed = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_idle_closed",
			Help: "The total number of connections closed because of SetMaxIdleConns",
		},
		[]string{sqlInstance},
	)
	ConnIdleTimeClosed = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_idle_time_closed",
			Help: "The total number of connections closed because of SetConnMaxIdleTime",
		},
		[]string{sqlInstance},
	)
	ConnLifetimeClosed = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_lifetime_closed",
			Help: "The total number of connections closed because of SetConnMaxLifetime",
		},
		[]string{sqlInstance},
	)
	ConnWaitMS = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "go_sql_conn_wait_ms",
			Help: "The total time blocked by waiting for a new connection, millisecond.",
		},
		[]string{sqlInstance},
	)
)

var (
	DefaultLatency = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name: "go_sql_latency",
			Help: "The latency of sql calls in microseconds.",
		},
		[]string{sqlInstance, sqlDatabase, sqlMethod, sqlStatus},
	)
)