func NewEventHandler(cf Config) (events.Handler, error) {
	h := &handler{listenAddr: cf.ListenAddr, errorSink: cf.ErrorSink}

	h.connections = prom.NewCounterVec(prom.CounterOpts{
		Name: "flux_connections_total",
		Help: "Number of TCP connections established",
	}, []string{"individual", "group", "src", "dst", "protocol"})

	httpLabels := []string{"individual", "group", "src", "dst", "method", "code"}

	h.http = prom.NewCounterVec(prom.CounterOpts{
		Name: "flux_http_total",
		Help: "Number of HTTP request/response exchanges",
	}, httpLabels)

	h.httpRoundtrip = prom.NewSummaryVec(prom.SummaryOpts{
		Name: "flux_http_roundtrip_usec",
		Help: "HTTP response roundtrip time in microseconds",
	}, httpLabels)

	h.httpTotal = prom.NewSummaryVec(prom.SummaryOpts{
		Name: "flux_http_total_usec",
		Help: "HTTP total response time in microseconds",
	}, httpLabels)

	if cf.AdvertiseAddr != "" {
		var err error
		if h.advertiser, err = newAdvertiser(cf); err != nil {
			return nil, err
		}
	}

	return h, nil
}

// NewExporter returns an initialized exporter
func NewExporter(server string) *Exporter {
	return &Exporter{
		mc: memcache.New(server),
		up: prometheus.NewGauge(
			prometheus.GaugeOpts{
				Name:        "up",
				Namespace:   namespace,
				Help:        "Are the servers up.",
				ConstLabels: prometheus.Labels{"server": server},
			},
		),
		uptime: prometheus.NewCounter(
			prometheus.CounterOpts{
				Name:        "uptime",
				Namespace:   namespace,
				Help:        "The uptime of the server.",
				ConstLabels: prometheus.Labels{"server": server},
			},
		),
		cache: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Name:        "cache",
				Namespace:   namespace,
				Help:        "The cache hits/misses broken down by command (get, set, etc.).",
				ConstLabels: prometheus.Labels{"server": server},
			},
			[]string{"command", "status"},
		),
		usage: prometheus.NewGaugeVec(
			prometheus.GaugeOpts{
				Name:        "usage",
				Namespace:   namespace,
				Help:        "Details the resource usage (items/connections) of the server, by time (current/total).",
				ConstLabels: prometheus.Labels{"server": server},
			},
			[]string{"time", "resource"},
		),
		bytes: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Name:        "bytes",
				Namespace:   namespace,
				Help:        "The bytes sent/received by the server.",
				ConstLabels: prometheus.Labels{"server": server},
			},
			[]string{"direction"},
		),
		removals: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Name:        "removal",
				Namespace:   namespace,
				Help:        "Number of items that have been evicted/expired (status), and if the were fetched ever or not.",
				ConstLabels: prometheus.Labels{"server": server},
			},
			[]string{"status", "fetched"},
		),
	}
}

// New constructs a neww Notifier.
func New(o *Options) *Notifier {
	ctx, cancel := context.WithCancel(context.Background())

	return &Notifier{
		queue:  make(model.Alerts, 0, o.QueueCapacity),
		ctx:    ctx,
		cancel: cancel,
		more:   make(chan struct{}, 1),
		opts:   o,

		latency: prometheus.NewSummaryVec(prometheus.SummaryOpts{
			Namespace: namespace,
			Subsystem: subsystem,
			Name:      "latency_seconds",
			Help:      "Latency quantiles for sending alert notifications (not including dropped notifications).",
		},
			[]string{alertmanagerLabel},
		),
		errors: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: subsystem,
			Name:      "errors_total",
			Help:      "Total number of errors sending alert notifications.",
		},
			[]string{alertmanagerLabel},
		),
		sent: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: subsystem,
			Name:      "sent_total",
			Help:      "Total number of alerts successfully sent.",
		},
			[]string{alertmanagerLabel},
		),
		dropped: prometheus.NewCounter(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: subsystem,
			Name:      "dropped_total",
			Help:      "Total number of alerts dropped due to alert manager missing in configuration.",
		}),
		queueLength: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Subsystem: subsystem,
			Name:      "queue_length",
			Help:      "The number of alert notifications in the queue.",
		}),
		queueCapacity: prometheus.MustNewConstMetric(
			prometheus.NewDesc(
				prometheus.BuildFQName(namespace, subsystem, "queue_capacity"),
				"The capacity of the alert notifications queue.",
				nil, nil,
			),
			prometheus.GaugeValue,
			float64(o.QueueCapacity),
		),
	}
}

func initPrometheusMetrics() {
	TotalClientCounter = stat.NewGauge(stat.GaugeOpts{
		Name: "total_clients",
		Help: "Total number of connected clients",
	})

	TotalNodes = stat.NewGauge(stat.GaugeOpts{
		Name: "meshnodes_total",
		Help: "Total number of Nodes",
	})

	TotalNodeTrafficRx = stat.NewCounter(stat.CounterOpts{
		Name: "total_traffic_rx",
		Help: "Total accumulated received traffic as reported by Nodes",
	})

	TotalNodeTrafficTx = stat.NewCounter(stat.CounterOpts{
		Name: "total_traffic_tx",
		Help: "Total accumulated transmitted traffic as reported by Nodes",
	})

	TotalNodeMgmtTrafficRx = stat.NewCounter(stat.CounterOpts{
		Name: "total_traffic_mgmt_rx",
		Help: "Total accumulated received management traffic as reported by Nodes",
	})

	TotalNodeMgmtTrafficTx = stat.NewCounter(stat.CounterOpts{
		Name: "total_traffic_mgmt_tx",
		Help: "Total accumulated transmitted management traffic as reported by Nodes",
	})

	OnlineNodes = stat.NewGauge(stat.GaugeOpts{
		Name: "meshnodes_online_total",
		Help: "All online nodes",
	})

	NodesTrafficRx = stat.NewCounterVec(stat.CounterOpts{
		Name: "meshnode_traffic_rx",
		Help: "Transmitted traffic from nodes",
	}, append(nodeLabels, "type"))

	NodesTrafficTx = stat.NewCounterVec(stat.CounterOpts{
		Name: "meshnode_traffic_tx",
		Help: "Received traffic on nodes",
	}, append(nodeLabels, "type"))

	NodesUptime = stat.NewCounterVec(stat.CounterOpts{
		Name: "meshnode_uptime",
		Help: "Uptime of meshnodes",
	}, nodeLabels)

	NodesClients = stat.NewGaugeVec(stat.GaugeOpts{
		Name: "meshnode_clients",
		Help: "Clients on single meshnodes",
	}, nodeLabels)
}

// Takes a prometheus registry and returns a new Collector exposing
// Device stats.
func NewDevstatCollector() (Collector, error) {
	return &devstatCollector{
		bytes: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Namespace: Namespace,
				Subsystem: devstatSubsystem,
				Name:      "bytes_total",
				Help:      "The total number of bytes in transactions.",
			},
			[]string{"device", "type"},
		),
		transfers: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Namespace: Namespace,
				Subsystem: devstatSubsystem,
				Name:      "transfers_total",
				Help:      "The total number of transactions.",
			},
			[]string{"device", "type"},
		),
		duration: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Namespace: Namespace,
				Subsystem: devstatSubsystem,
				Name:      "duration_seconds_total",
				Help:      "The total duration of transactions in seconds.",
			},
			[]string{"device", "type"},
		),
		busyTime: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Namespace: Namespace,
				Subsystem: devstatSubsystem,
				Name:      "busy_time_seconds_total",
				Help:      "Total time the device had one or more transactions outstanding in seconds.",
			},
			[]string{"device"},
		),
		blocks: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Namespace: Namespace,
				Subsystem: devstatSubsystem,
				Name:      "blocks_transferred_total",
				Help:      "The total number of blocks transferred.",
			},
			[]string{"device"},
		),
	}, nil
}

func init() {
	prometheus.MustRegister(memAllocBytesGauge)
	prometheus.MustRegister(availFSGauge)

	prometheus.MustRegister(&cpuTimeMetric{prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Subsystem: "process",
			Name:      "cpu_nsec",
			Help:      "CPU time spent in ns, split by user/system.",
		},
		[]string{"mode"},
	)})

	prometheus.MustRegister(&diskStatsMetric{
		reads: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Subsystem: "system",
				Name:      "disk_reads",
				Help:      "Disk reads, per device name (e.g. xvda).",
			},
			[]string{"device"},
		),
		writes: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Subsystem: "system",
				Name:      "disk_writes",
				Help:      "Disk writes, per device name (e.g. xvda).",
			},
			[]string{"device"},
		),
		readbytes: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Subsystem: "system",
				Name:      "disk_read_bytes",
				Help:      "Bytes read from disk, per device name (e.g. xvda).",
			},
			[]string{"device"},
		),
		writtenbytes: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Subsystem: "system",
				Name:      "disk_written_bytes",
				Help:      "Bytes written to disk, per device name (e.g. xvda).",
			},
			[]string{"device"},
		),
	})
}

// NewExporter returns a new MySQL exporter for the provided DSN.
func NewExporter(dsn string) *Exporter {
	return &Exporter{
		dsn: dsn,
		duration: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Subsystem: exporter,
			Name:      "last_scrape_duration_seconds",
			Help:      "Duration of the last scrape of metrics from MySQL.",
		}),
		totalScrapes: prometheus.NewCounter(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: exporter,
			Name:      "scrapes_total",
			Help:      "Total number of times MySQL was scraped for metrics.",
		}),
		scrapeErrors: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: exporter,
			Name:      "scrape_errors_total",
			Help:      "Total number of times an error occurred scraping a MySQL.",
		}, []string{"collector"}),
		error: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Subsystem: exporter,
			Name:      "last_scrape_error",
			Help:      "Whether the last scrape of metrics from MySQL resulted in an error (1 for error, 0 for success).",
		}),
		mysqldUp: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Name:      "up",
			Help:      "Whether the MySQL server is up.",
		}),
	}
}

// NewMiddleware returns a new prometheus Middleware handler.
func NewMiddleware(name string, buckets ...float64) *Middleware {
	var m Middleware
	m.reqs = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name:        reqsName,
			Help:        "How many HTTP requests processed, partitioned by status code, method and HTTP path.",
			ConstLabels: prometheus.Labels{"service": name},
		},
		[]string{"code", "method", "path"},
	)
	prometheus.MustRegister(m.reqs)

	if len(buckets) == 0 {
		buckets = dflBuckets
	}
	m.latency = prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Name:        latencyName,
		Help:        "How long it took to process the request, partitioned by status code, method and HTTP path.",
		ConstLabels: prometheus.Labels{"service": name},
		Buckets:     buckets,
	},
		[]string{"code", "method", "path"},
	)
	prometheus.MustRegister(m.latency)
	return &m
}

// Creates and returns a new Manager.
func New() *Manager {
	refreshChannel := make(chan string, 10)
	quitChannel := make(chan int)

	refreshCounter := prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "proxym",
		Subsystem: "refresh",
		Name:      "count",
		Help:      "Number of refreshes triggered",
	}, []string{"result"})
	prometheus.MustRegister(refreshCounter)

	var c Config
	envconfig.Process("proxym", &c)

	m := &Manager{
		Config:         &c,
		httpRouter:     pat.New(),
		refresh:        refreshChannel,
		refreshCounter: refreshCounter,
		quit:           quitChannel,
	}

	m.httpRouter.Get("/metrics", prometheus.Handler())

	return m
}

// NewExporter returns an initialized Exporter.
func NewExporter(uri string) *Exporter {
	return &Exporter{
		URI: uri,
		scrapeFailures: prometheus.NewCounter(prometheus.CounterOpts{
			Namespace: namespace,
			Name:      "exporter_scrape_failures_total",
			Help:      "Number of errors while scraping nginx.",
		}),
		processedConnections: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Name:      "connections_processed_total",
			Help:      "Number of connections processed by nginx",
		},
			[]string{"stage"},
		),
		currentConnections: prometheus.NewGaugeVec(prometheus.GaugeOpts{
			Namespace: namespace,
			Name:      "connections_current",
			Help:      "Number of connections currently processed by nginx",
		},
			[]string{"state"},
		),
		client: &http.Client{
			Transport: &http.Transport{
				TLSClientConfig: &tls.Config{InsecureSkipVerify: *insecure},
			},
		},
	}
}

func TestToReader(t *testing.T) {
	cntVec := prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name:        "name",
			Help:        "docstring",
			ConstLabels: prometheus.Labels{"constname": "constvalue"},
		},
		[]string{"labelname"},
	)
	cntVec.WithLabelValues("val1").Inc()
	cntVec.WithLabelValues("val2").Inc()

	reg := prometheus.NewRegistry()
	reg.MustRegister(cntVec)

	want := `prefix.name.constname.constvalue.labelname.val1 1 1477043
prefix.name.constname.constvalue.labelname.val2 1 1477043
`
	mfs, err := reg.Gather()
	if err != nil {
		t.Fatalf("error: %v", err)
	}

	now := model.Time(1477043083)
	var buf bytes.Buffer
	err = writeMetrics(&buf, mfs, "prefix", now)
	if err != nil {
		t.Fatalf("error: %v", err)
	}

	if got := buf.String(); want != got {
		t.Fatalf("wanted \n%s\n, got \n%s\n", want, got)
	}
}

func ExampleCounterVec() {
	binaryVersion := flag.String("environment", "test", "Execution environment: test, staging, production.")
	flag.Parse()

	httpReqs := prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name:        "http_requests_total",
			Help:        "How many HTTP requests processed, partitioned by status code and HTTP method.",
			ConstLabels: prometheus.Labels{"env": *binaryVersion},
		},
		[]string{"code", "method"},
	)
	prometheus.MustRegister(httpReqs)

	httpReqs.WithLabelValues("404", "POST").Add(42)

	// If you have to access the same set of labels very frequently, it
	// might be good to retrieve the metric only once and keep a handle to
	// it. But beware of deletion of that metric, see below!
	m := httpReqs.WithLabelValues("200", "GET")
	for i := 0; i < 1000000; i++ {
		m.Inc()
	}
	// Delete a metric from the vector. If you have previously kept a handle
	// to that metric (as above), future updates via that handle will go
	// unseen (even if you re-create a metric with the same label set
	// later).
	httpReqs.DeleteLabelValues("200", "GET")
	// Same thing with the more verbose Labels syntax.
	httpReqs.Delete(prometheus.Labels{"method": "GET", "code": "200"})
}

func newMesosExporter(opts *exporterOpts) *periodicExporter {
	e := &periodicExporter{
		errors: prometheus.NewCounterVec(
			prometheus.CounterOpts{
				Namespace: "mesos_exporter",
				Name:      "slave_scrape_errors_total",
				Help:      "Current total scrape errors",
			},
			[]string{"slave"},
		),
		opts: opts,
	}
	e.slaves.urls = []string{e.opts.localURL}

	if e.opts.autoDiscover {
		log.Info("auto discovery enabled from command line flag.")

		// Update nr. of mesos slaves every 10 minutes
		e.updateSlaves()
		go runEvery(e.updateSlaves, 10*time.Minute)
	}

	// Fetch slave metrics every interval
	go runEvery(e.scrapeSlaves, e.opts.interval)

	return e
}

func (c *netDevCollector) Update(ch chan<- prometheus.Metric) (err error) {
	netDev, err := getNetDevStats()
	if err != nil {
		return fmt.Errorf("couldn't get netstats: %s", err)
	}
	for direction, devStats := range netDev {
		for dev, stats := range devStats {
			for t, value := range stats {
				key := direction + "_" + t
				if _, ok := c.metrics[key]; !ok {
					c.metrics[key] = prometheus.NewCounterVec(
						prometheus.CounterOpts{
							Namespace: Namespace,
							Subsystem: netDevSubsystem,
							Name:      key,
							Help:      fmt.Sprintf("%s %s from getifaddrs().", t, direction),
						},
						[]string{"device"},
					)
				}
				v, err := strconv.ParseFloat(value, 64)
				if err != nil {
					return fmt.Errorf("invalid value %s in netstats: %s", value, err)
				}
				c.metrics[key].WithLabelValues(dev).Set(v)
			}
		}
	}
	for _, m := range c.metrics {
		m.Collect(ch)
	}
	return err
}

func TestPush(t *testing.T) {
	reg := prometheus.NewRegistry()
	cntVec := prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name:        "name",
			Help:        "docstring",
			ConstLabels: prometheus.Labels{"constname": "constvalue"},
		},
		[]string{"labelname"},
	)
	cntVec.WithLabelValues("val1").Inc()
	cntVec.WithLabelValues("val2").Inc()
	reg.MustRegister(cntVec)

	host := "localhost"
	port := ":56789"
	b, err := NewBridge(&Config{
		URL:      host + port,
		Gatherer: reg,
		Prefix:   "prefix",
	})
	if err != nil {
		t.Fatalf("error creating bridge: %v", err)
	}

	nmg, err := newMockGraphite(port)
	if err != nil {
		t.Fatalf("error creating mock graphite: %v", err)
	}
	defer nmg.Close()

	err = b.Push()
	if err != nil {
		t.Fatalf("error pushing: %v", err)
	}

	wants := []string{
		"prefix.name.constname.constvalue.labelname.val1 1",
		"prefix.name.constname.constvalue.labelname.val2 1",
	}

	select {
	case got := <-nmg.readc:
		for _, want := range wants {
			matched, err := regexp.MatchString(want, got)
			if err != nil {
				t.Fatalf("error pushing: %v", err)
			}
			if !matched {
				t.Fatalf("missing metric:\nno match for %s received by server:\n%s", want, got)
			}
		}
		return
	case err := <-nmg.errc:
		t.Fatalf("error reading push: %v", err)
	case <-time.After(50 * time.Millisecond):
		t.Fatalf("no result from graphite server")
	}
}

func counter(subsystem, name, help string, labels ...string) *prometheus.CounterVec {
	return prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "mesos",
		Subsystem: subsystem,
		Name:      name,
		Help:      help,
	}, labels)
}

func main() {
	cfg, err := New()
	if err != nil {
		log.Fatalf("Failed to parse config: %s", err)
		return
	}

	runs := prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "elasticsearch_backup_runs_total",
			Help: "Number of elasticsearch backup runs",
		},
		[]string{"status"},
	)
	runs = prometheus.MustRegisterOrGet(runs).(*prometheus.CounterVec)
	duration := prometheus.NewSummaryVec(
		prometheus.SummaryOpts{
			Name: "elasticsearch_backup_duration",
			Help: "Duration of elasticsearch backup runs",
		},
		[]string{"operation"},
	)
	duration = prometheus.MustRegisterOrGet(duration).(*prometheus.SummaryVec)

	go listen()

	interval := time.Hour * time.Duration(cfg.Interval)
	for {
		t0 := time.Now()
		opFunc := func() error {
			return backupAndRemove(cfg)
		}
		logFunc := func(err error, wait time.Duration) {
			log.Warnf("Failed to connect to ES: %s. Retry in %s", err, wait)
		}
		bo := backoff.NewExponentialBackOff()
		bo.InitialInterval = time.Second
		bo.MaxInterval = 60 * time.Second
		bo.MaxElapsedTime = 15 * time.Minute
		log.Infof("Attempting Snapshot ...")
		err := backoff.RetryNotify(opFunc, bo, logFunc)
		if err != nil {
			runs.WithLabelValues("failed").Inc()
			log.Warnf("Failed to delete snapshots: %s", err)
			continue
		}
		runs.WithLabelValues("ok").Inc()
		d0 := float64(time.Since(t0)) / float64(time.Microsecond)
		duration.WithLabelValues("backup").Observe(d0)

		if interval < time.Second {
			break
		}
		log.Infof("Waiting %s until next run", interval.String())
		time.Sleep(interval)
	}
	os.Exit(0)
}

// Takes a prometheus registry and returns a new Collector exposing
// Filesystems stats.
func NewFilesystemCollector() (Collector, error) {
	subsystem := "filesystem"
	mountPointPattern := regexp.MustCompile(*ignoredMountPoints)
	filesystemsTypesPattern := regexp.MustCompile(*ignoredFSTypes)

	sizeDesc := prometheus.NewDesc(
		prometheus.BuildFQName(Namespace, subsystem, "size"),
		"Filesystem size in bytes.",
		filesystemLabelNames, nil,
	)

	freeDesc := prometheus.NewDesc(
		prometheus.BuildFQName(Namespace, subsystem, "free"),
		"Filesystem free space in bytes.",
		filesystemLabelNames, nil,
	)

	availDesc := prometheus.NewDesc(
		prometheus.BuildFQName(Namespace, subsystem, "avail"),
		"Filesystem space available to non-root users in bytes.",
		filesystemLabelNames, nil,
	)

	filesDesc := prometheus.NewDesc(
		prometheus.BuildFQName(Namespace, subsystem, "files"),
		"Filesystem total file nodes.",
		filesystemLabelNames, nil,
	)

	filesFreeDesc := prometheus.NewDesc(
		prometheus.BuildFQName(Namespace, subsystem, "files_free"),
		"Filesystem total free file nodes.",
		filesystemLabelNames, nil,
	)

	roDesc := prometheus.NewDesc(
		prometheus.BuildFQName(Namespace, subsystem, "readonly"),
		"Filesystem read-only status.",
		filesystemLabelNames, nil,
	)

	devErrors := prometheus.NewCounterVec(prometheus.CounterOpts{
		Name: prometheus.BuildFQName(Namespace, subsystem, "device_errors_total"),
		Help: "Total number of errors occurred when getting stats for device",
	}, filesystemLabelNames)

	return &filesystemCollector{
		ignoredMountPointsPattern: mountPointPattern,
		ignoredFSTypesPattern:     filesystemsTypesPattern,
		sizeDesc:                  sizeDesc,
		freeDesc:                  freeDesc,
		availDesc:                 availDesc,
		filesDesc:                 filesDesc,
		filesFreeDesc:             filesFreeDesc,
		roDesc:                    roDesc,
		devErrors:                 devErrors,
	}, nil
}

// return new empty exporter
func NewMySQLExporter(dsn string) *Exporter {
	return &Exporter{
		dsn: dsn,
		duration: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Name:      "exporter_last_scrape_duration_seconds",
			Help:      "The last scrape duration.",
		}),
		totalScrapes: prometheus.NewCounter(prometheus.CounterOpts{
			Namespace: namespace,
			Name:      "exporter_scrapes_total",
			Help:      "Current total mysqld scrapes.",
		}),
		error: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Name:      "exporter_last_scrape_error",
			Help:      "The last scrape error status.",
		}),
		metrics: map[string]prometheus.Gauge{},
		commands: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: globalStatus,
			Name:      "commands_total",
			Help:      "Number of executed mysql commands.",
		}, []string{"command"}),
		connectionErrors: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: globalStatus,
			Name:      "connection_errors_total",
			Help:      "Number of mysql connection errors.",
		}, []string{"error"}),
		innodbRows: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: globalStatus,
			Name:      "innodb_rows_total",
			Help:      "Mysql Innodb row operations.",
		}, []string{"operation"}),
		performanceSchema: prometheus.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: globalStatus,
			Name:      "performance_schema_total",
			Help:      "Mysql instrumentations that could not be loaded or created due to memory constraints",
		}, []string{"instrumentation"}),
	}
}

func newMeasurer() grpcinstrument.Measurer {
	return &measurer{
		registry: &registry{
			total: prometheus.NewCounterVec(prometheus.CounterOpts{
				Name: "grpc_calls_total",
				Help: "Number of gRPC calls received by the server being instrumented.",
			}, []string{"service", "method"}),
			errors: prometheus.NewCounterVec(prometheus.CounterOpts{
				Name: "grpc_calls_errors",
				Help: "Number of gRPC calls that returned an error.",
			}, []string{"service", "method"}),
			duration: prometheus.NewHistogramVec(prometheus.HistogramOpts{
				Name: "grpc_calls_durations",
				Help: "Duration of gRPC calls.",
			}, []string{"service", "method"}),
		},
	}
}