func (b *Bcache) gatherBcache(bdev string, acc inputs.Accumulator) error {
	tags := getTags(bdev)
	metrics, err := filepath.Glob(bdev + "/stats_total/*")
	if len(metrics) < 0 {
		return errors.New("Can't read any stats file")
	}
	file, err := ioutil.ReadFile(bdev + "/dirty_data")
	if err != nil {
		return err
	}
	rawValue := strings.TrimSpace(string(file))
	value := prettyToBytes(rawValue)

	fields := make(map[string]interface{})
	fields["dirty_data"] = value

	for _, path := range metrics {
		key := filepath.Base(path)
		file, err := ioutil.ReadFile(path)
		rawValue := strings.TrimSpace(string(file))
		if err != nil {
			return err
		}
		if key == "bypassed" {
			value := prettyToBytes(rawValue)
			fields[key] = value
		} else {
			value, _ := strconv.ParseUint(rawValue, 10, 64)
			fields[key] = value
		}
	}
	acc.AddFields("bcache", fields, tags)
	return nil
}

func readAerospikeStats(
	stats map[string]string,
	acc inputs.Accumulator,
	host string,
	namespace string,
) {
	fields := make(map[string]interface{})
	tags := map[string]string{
		"aerospike_host": host,
		"namespace":      "_service",
	}

	if namespace != "" {
		tags["namespace"] = namespace
	}
	for key, value := range stats {
		// We are going to ignore all string based keys
		val, err := strconv.ParseInt(value, 10, 64)
		if err == nil {
			if strings.Contains(key, "-") {
				key = strings.Replace(key, "-", "_", -1)
			}
			fields[key] = val
		}
	}
	acc.AddFields("aerospike", fields, tags)
}

func gatherPoolStats(pool poolInfo, acc inputs.Accumulator) error {
	lines, err := internal.ReadLines(pool.ioFilename)
	if err != nil {
		return err
	}

	if len(lines) != 3 {
		return err
	}

	keys := strings.Fields(lines[1])
	values := strings.Fields(lines[2])

	keyCount := len(keys)

	if keyCount != len(values) {
		return fmt.Errorf("Key and value count don't match Keys:%v Values:%v", keys, values)
	}

	tag := map[string]string{"pool": pool.name}
	fields := make(map[string]interface{})
	for i := 0; i < keyCount; i++ {
		value, err := strconv.ParseInt(values[i], 10, 64)
		if err != nil {
			return err
		}
		fields[keys[i]] = value
	}
	acc.AddFields("zfs_pool", fields, tag)

	return nil
}

func gatherOverview(r *RabbitMQ, acc inputs.Accumulator, errChan chan error) {
	overview := &OverviewResponse{}

	err := r.requestJSON("/api/overview", &overview)
	if err != nil {
		errChan <- err
		return
	}

	if overview.QueueTotals == nil || overview.ObjectTotals == nil || overview.MessageStats == nil {
		errChan <- fmt.Errorf("Wrong answer from rabbitmq. Probably auth issue")
		return
	}

	tags := map[string]string{"url": r.URL}
	if r.Name != "" {
		tags["name"] = r.Name
	}
	fields := map[string]interface{}{
		"messages":           overview.QueueTotals.Messages,
		"messages_ready":     overview.QueueTotals.MessagesReady,
		"messages_unacked":   overview.QueueTotals.MessagesUnacknowledged,
		"channels":           overview.ObjectTotals.Channels,
		"connections":        overview.ObjectTotals.Connections,
		"consumers":          overview.ObjectTotals.Consumers,
		"exchanges":          overview.ObjectTotals.Exchanges,
		"queues":             overview.ObjectTotals.Queues,
		"messages_acked":     overview.MessageStats.Ack,
		"messages_delivered": overview.MessageStats.Deliver,
		"messages_published": overview.MessageStats.Publish,
	}
	acc.AddFields("rabbitmq_overview", fields, tags)

	errChan <- nil
}

// Process pool data in Twemproxy stats
func (t *Twemproxy) processPool(
	acc inputs.Accumulator,
	tags map[string]string,
	data map[string]interface{},
) {
	serverTags := make(map[string]map[string]string)

	fields := make(map[string]interface{})
	for key, value := range data {
		switch key {
		case "client_connections", "forward_error", "client_err", "server_ejects", "fragments", "client_eof":
			if val, ok := value.(float64); ok {
				fields[key] = val
			}
		default:
			if data, ok := value.(map[string]interface{}); ok {
				if _, ok := serverTags[key]; !ok {
					serverTags[key] = copyTags(tags)
					serverTags[key]["server"] = key
				}
				t.processServer(acc, serverTags[key], data)
			}
		}
	}
	acc.AddFields("twemproxy_pool", fields, tags)
}

// Process Twemproxy server stats
func (t *Twemproxy) processStat(
	acc inputs.Accumulator,
	tags map[string]string,
	data map[string]interface{},
) {
	if source, ok := data["source"]; ok {
		if val, ok := source.(string); ok {
			tags["source"] = val
		}
	}

	fields := make(map[string]interface{})
	metrics := []string{"total_connections", "curr_connections", "timestamp"}
	for _, m := range metrics {
		if value, ok := data[m]; ok {
			if val, ok := value.(float64); ok {
				fields[m] = val
			}
		}
	}
	acc.AddFields("twemproxy", fields, tags)

	for _, pool := range t.Pools {
		if poolStat, ok := data[pool]; ok {
			if data, ok := poolStat.(map[string]interface{}); ok {
				poolTags := copyTags(tags)
				poolTags["pool"] = pool
				t.processPool(acc, poolTags, data)
			}
		}
	}
}

func (d *MongodbData) flush(acc inputs.Accumulator) {
	acc.AddFields(
		"mongodb",
		d.Fields,
		d.Tags,
		d.StatLine.Time,
	)
	d.Fields = make(map[string]interface{})
}

func (k *Kafka) Gather(acc inputs.Accumulator) error {
	k.Lock()
	defer k.Unlock()
	npoints := len(k.pointChan)
	for i := 0; i < npoints; i++ {
		point := <-k.pointChan
		acc.AddFields(point.Name(), point.Fields(), point.Tags(), point.Time())
	}
	return nil
}

// Import HTTP stat data into Telegraf system
func importMetric(r io.Reader, acc inputs.Accumulator, host string) (poolStat, error) {
	stats := make(poolStat)
	var currentPool string

	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		statLine := scanner.Text()
		keyvalue := strings.Split(statLine, ":")

		if len(keyvalue) < 2 {
			continue
		}
		fieldName := strings.Trim(keyvalue[0], " ")
		// We start to gather data for a new pool here
		if fieldName == PF_POOL {
			currentPool = strings.Trim(keyvalue[1], " ")
			stats[currentPool] = make(metric)
			continue
		}

		// Start to parse metric for current pool
		switch fieldName {
		case PF_ACCEPTED_CONN,
			PF_LISTEN_QUEUE,
			PF_MAX_LISTEN_QUEUE,
			PF_LISTEN_QUEUE_LEN,
			PF_IDLE_PROCESSES,
			PF_ACTIVE_PROCESSES,
			PF_TOTAL_PROCESSES,
			PF_MAX_ACTIVE_PROCESSES,
			PF_MAX_CHILDREN_REACHED,
			PF_SLOW_REQUESTS:
			fieldValue, err := strconv.ParseInt(strings.Trim(keyvalue[1], " "), 10, 64)
			if err == nil {
				stats[currentPool][fieldName] = fieldValue
			}
		}
	}

	// Finally, we push the pool metric
	for pool := range stats {
		tags := map[string]string{
			"url":  host,
			"pool": pool,
		}
		fields := make(map[string]interface{})
		for k, v := range stats[pool] {
			fields[strings.Replace(k, " ", "_", -1)] = v
		}
		acc.AddFields("phpfpm", fields, tags)
	}

	return stats, nil
}

func (e *Engine) AddEngineStats(
	keys []string,
	acc inputs.Accumulator,
	tags map[string]string,
) {
	engine := reflect.ValueOf(e).Elem()
	fields := make(map[string]interface{})
	for _, key := range keys {
		fields[key] = engine.FieldByName(engineStats[key]).Interface()
	}
	acc.AddFields("rethinkdb_engine", fields, tags)
}

func (s *Storage) AddStats(acc inputs.Accumulator, tags map[string]string) {
	fields := map[string]interface{}{
		"cache_bytes_in_use":            s.Cache.BytesInUse,
		"disk_read_bytes_per_sec":       s.Disk.ReadBytesPerSec,
		"disk_read_bytes_total":         s.Disk.ReadBytesTotal,
		"disk_written_bytes_per_sec":    s.Disk.WriteBytesPerSec,
		"disk_written_bytes_total":      s.Disk.WriteBytesTotal,
		"disk_usage_data_bytes":         s.Disk.SpaceUsage.Data,
		"disk_usage_garbage_bytes":      s.Disk.SpaceUsage.Garbage,
		"disk_usage_metadata_bytes":     s.Disk.SpaceUsage.Metadata,
		"disk_usage_preallocated_bytes": s.Disk.SpaceUsage.Prealloc,
	}
	acc.AddFields("rethinkdb", fields, tags)
}

func gatherQueues(r *RabbitMQ, acc inputs.Accumulator, errChan chan error) {
	// Gather information about queues
	queues := make([]Queue, 0)
	err := r.requestJSON("/api/queues", &queues)
	if err != nil {
		errChan <- err
		return
	}

	for _, queue := range queues {
		if !r.shouldGatherQueue(queue) {
			continue
		}
		tags := map[string]string{
			"url":         r.URL,
			"queue":       queue.Name,
			"vhost":       queue.Vhost,
			"node":        queue.Node,
			"durable":     strconv.FormatBool(queue.Durable),
			"auto_delete": strconv.FormatBool(queue.AutoDelete),
		}

		acc.AddFields(
			"rabbitmq_queue",
			map[string]interface{}{
				// common information
				"consumers":            queue.Consumers,
				"consumer_utilisation": queue.ConsumerUtilisation,
				"memory":               queue.Memory,
				// messages information
				"messages":                  queue.Messages,
				"messages_ready":            queue.MessagesReady,
				"messages_unack":            queue.MessagesUnacknowledged,
				"messages_ack":              queue.MessageStats.Ack,
				"messages_ack_rate":         queue.MessageStats.AckDetails.Rate,
				"messages_deliver":          queue.MessageStats.Deliver,
				"messages_deliver_rate":     queue.MessageStats.DeliverDetails.Rate,
				"messages_deliver_get":      queue.MessageStats.DeliverGet,
				"messages_deliver_get_rate": queue.MessageStats.DeliverGetDetails.Rate,
				"messages_publish":          queue.MessageStats.Publish,
				"messages_publish_rate":     queue.MessageStats.PublishDetails.Rate,
				"messages_redeliver":        queue.MessageStats.Redeliver,
				"messages_redeliver_rate":   queue.MessageStats.RedeliverDetails.Rate,
			},
			tags,
		)
	}

	errChan <- nil
}

func (p *Ping) Gather(acc inputs.Accumulator) error {

	var wg sync.WaitGroup
	errorChannel := make(chan error, len(p.Urls)*2)

	// Spin off a go routine for each url to ping
	for _, url := range p.Urls {
		wg.Add(1)
		go func(url string, acc inputs.Accumulator) {
			defer wg.Done()
			args := p.args(url)
			out, err := p.pingHost(args...)
			if err != nil {
				// Combine go err + stderr output
				errorChannel <- errors.New(
					strings.TrimSpace(out) + ", " + err.Error())
			}
			tags := map[string]string{"url": url}
			trans, rec, avg, err := processPingOutput(out)
			if err != nil {
				// fatal error
				errorChannel <- err
				return
			}
			// Calculate packet loss percentage
			loss := float64(trans-rec) / float64(trans) * 100.0
			fields := map[string]interface{}{
				"packets_transmitted": trans,
				"packets_received":    rec,
				"percent_packet_loss": loss,
				"average_response_ms": avg,
			}
			acc.AddFields("ping", fields, tags)
		}(url, acc)
	}

	wg.Wait()
	close(errorChannel)

	// Get all errors and return them as one giant error
	errorStrings := []string{}
	for err := range errorChannel {
		errorStrings = append(errorStrings, err.Error())
	}

	if len(errorStrings) == 0 {
		return nil
	}
	return errors.New(strings.Join(errorStrings, "\n"))
}

// Gather reads stats from all lustre targets
func (l *Lustre2) Gather(acc inputs.Accumulator) error {
	l.allFields = make(map[string]map[string]interface{})

	if len(l.Ost_procfiles) == 0 {
		// read/write bytes are in obdfilter/<ost_name>/stats
		err := l.GetLustreProcStats("/proc/fs/lustre/obdfilter/*/stats",
			wanted_ost_fields, acc)
		if err != nil {
			return err
		}
		// cache counters are in osd-ldiskfs/<ost_name>/stats
		err = l.GetLustreProcStats("/proc/fs/lustre/osd-ldiskfs/*/stats",
			wanted_ost_fields, acc)
		if err != nil {
			return err
		}
	}

	if len(l.Mds_procfiles) == 0 {
		// Metadata server stats
		err := l.GetLustreProcStats("/proc/fs/lustre/mdt/*/md_stats",
			wanted_mds_fields, acc)
		if err != nil {
			return err
		}
	}

	for _, procfile := range l.Ost_procfiles {
		err := l.GetLustreProcStats(procfile, wanted_ost_fields, acc)
		if err != nil {
			return err
		}
	}
	for _, procfile := range l.Mds_procfiles {
		err := l.GetLustreProcStats(procfile, wanted_mds_fields, acc)
		if err != nil {
			return err
		}
	}

	for name, fields := range l.allFields {
		tags := map[string]string{
			"name": name,
		}
		acc.AddFields("lustre2", fields, tags)
	}

	return nil
}

func (s *Trig) Gather(acc inputs.Accumulator) error {
	sinner := math.Sin((s.x*math.Pi)/5.0) * s.Amplitude
	cosinner := math.Cos((s.x*math.Pi)/5.0) * s.Amplitude

	fields := make(map[string]interface{})
	fields["sine"] = sinner
	fields["cosine"] = cosinner

	tags := make(map[string]string)

	s.x += 1.0
	acc.AddFields("trig", fields, tags)

	return nil
}

func (z *Zookeeper) gatherServer(address string, acc inputs.Accumulator) error {
	_, _, err := net.SplitHostPort(address)
	if err != nil {
		address = address + ":2181"
	}

	c, err := net.DialTimeout("tcp", address, defaultTimeout)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		return err
	}
	defer c.Close()

	fmt.Fprintf(c, "%s\n", "mntr")
	rdr := bufio.NewReader(c)
	scanner := bufio.NewScanner(rdr)

	service := strings.Split(address, ":")
	if len(service) != 2 {
		return fmt.Errorf("Invalid service address: %s", address)
	}
	tags := map[string]string{"server": service[0], "port": service[1]}

	fields := make(map[string]interface{})
	for scanner.Scan() {
		line := scanner.Text()

		re := regexp.MustCompile(`^zk_(\w+)\s+([\w\.\-]+)`)
		parts := re.FindStringSubmatch(string(line))

		if len(parts) != 3 {
			return fmt.Errorf("unexpected line in mntr response: %q", line)
		}

		measurement := strings.TrimPrefix(parts[1], "zk_")
		sValue := string(parts[2])

		iVal, err := strconv.ParseInt(sValue, 10, 64)
		if err == nil {
			fields[measurement] = iVal
		} else {
			fields[measurement] = sValue
		}
	}
	acc.AddFields("zookeeper", fields, tags)

	return nil
}

// Process backend server(redis/memcached) stats
func (t *Twemproxy) processServer(
	acc inputs.Accumulator,
	tags map[string]string,
	data map[string]interface{},
) {
	fields := make(map[string]interface{})
	for key, value := range data {
		switch key {
		default:
			if val, ok := value.(float64); ok {
				fields[key] = val
			}
		}
	}
	acc.AddFields("twemproxy_pool_server", fields, tags)
}

func (j *Jolokia) Gather(acc inputs.Accumulator) error {
	context := j.Context //"/jolokia/read"
	servers := j.Servers
	metrics := j.Metrics
	tags := make(map[string]string)

	for _, server := range servers {
		tags["server"] = server.Name
		tags["port"] = server.Port
		tags["host"] = server.Host
		fields := make(map[string]interface{})
		for _, metric := range metrics {

			measurement := metric.Name
			jmxPath := metric.Jmx

			// Prepare URL
			requestUrl, err := url.Parse("http://" + server.Host + ":" +
				server.Port + context + jmxPath)
			if err != nil {
				return err
			}
			if server.Username != "" || server.Password != "" {
				requestUrl.User = url.UserPassword(server.Username, server.Password)
			}

			out, _ := j.getAttr(requestUrl)

			if values, ok := out["value"]; ok {
				switch t := values.(type) {
				case map[string]interface{}:
					for k, v := range t {
						fields[measurement+"_"+k] = v
					}
				case interface{}:
					fields[measurement] = t
				}
			} else {
				fmt.Printf("Missing key 'value' in '%s' output response\n",
					requestUrl.String())
			}
		}
		acc.AddFields("jolokia", fields, tags)
	}

	return nil
}

func (z *Zfs) Gather(acc inputs.Accumulator) error {
	kstatMetrics := z.KstatMetrics
	if len(kstatMetrics) == 0 {
		kstatMetrics = []string{"arcstats", "zfetchstats", "vdev_cache_stats"}
	}

	kstatPath := z.KstatPath
	if len(kstatPath) == 0 {
		kstatPath = "/proc/spl/kstat/zfs"
	}

	pools := getPools(kstatPath)
	tags := getTags(pools)

	if z.PoolMetrics {
		for _, pool := range pools {
			err := gatherPoolStats(pool, acc)
			if err != nil {
				return err
			}
		}
	}

	fields := make(map[string]interface{})
	for _, metric := range kstatMetrics {
		lines, err := internal.ReadLines(kstatPath + "/" + metric)
		if err != nil {
			return err
		}
		for i, line := range lines {
			if i == 0 || i == 1 {
				continue
			}
			if len(line) < 1 {
				continue
			}
			rawData := strings.Split(line, " ")
			key := metric + "_" + rawData[0]
			rawValue := rawData[len(rawData)-1]
			value, _ := strconv.ParseInt(rawValue, 10, 64)
			fields[key] = value
		}
	}
	acc.AddFields("zfs", fields, tags)
	return nil
}

func (g *Prometheus) gatherURL(url string, acc inputs.Accumulator) error {
	resp, err := http.Get(url)
	if err != nil {
		return fmt.Errorf("error making HTTP request to %s: %s", url, err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("%s returned HTTP status %s", url, resp.Status)
	}
	format := expfmt.ResponseFormat(resp.Header)

	decoder := expfmt.NewDecoder(resp.Body, format)

	options := &expfmt.DecodeOptions{
		Timestamp: model.Now(),
	}
	sampleDecoder := &expfmt.SampleDecoder{
		Dec:  decoder,
		Opts: options,
	}

	for {
		var samples model.Vector
		err := sampleDecoder.Decode(&samples)
		if err == io.EOF {
			break
		} else if err != nil {
			return fmt.Errorf("error getting processing samples for %s: %s",
				url, err)
		}
		for _, sample := range samples {
			tags := make(map[string]string)
			for key, value := range sample.Metric {
				if key == model.MetricNameLabel {
					continue
				}
				tags[string(key)] = string(value)
			}
			acc.Add("prometheus_"+string(sample.Metric[model.MetricNameLabel]),
				float64(sample.Value), tags)
		}
	}

	return nil
}