Make variable name more meaningful

src/modules/collector/sys/funcs/dfstat.go

@@ -11,15 +11,17 @@ import (
 	"github.com/toolkits/pkg/nux"
 )
 
-func DeviceMetrics() (L []*dataobj.MetricValue) {
+func DeviceMetrics() []*dataobj.MetricValue {
+	ret := make([]*dataobj.MetricValue, 0)
+
 	mountPoints, err := nux.ListMountPoint()
 	fsFileFilter := make(map[string]struct{}) //过滤 /proc/mounts 出现重复的fsFile
 	if err != nil {
 		logger.Error("collect device metrics fail:", err)
-		return
+		return ret
 	}
 
-	var myMountPoints map[string]bool = make(map[string]bool)
+	var myMountPoints = make(map[string]bool)
 	if len(sys.Config.MountPoint) > 0 {
 		for _, mp := range sys.Config.MountPoint {
 			myMountPoints[mp] = true
@@ -39,6 +41,7 @@ func DeviceMetrics() (L []*dataobj.MetricValue) {
 				continue
 			}
 		}
+
 		if _, exists := fsFileFilter[fsFile]; exists {
 			logger.Debugf("mount point %s was collected", fsFile)
 			continue
@@ -65,29 +68,29 @@ func DeviceMetrics() (L []*dataobj.MetricValue) {
 		diskUsed += du.BlocksUsed
 
 		tags := fmt.Sprintf("mount=%s", du.FsFile)
-		L = append(L, GaugeValue("disk.bytes.total", du.BlocksAll, tags))
-		L = append(L, GaugeValue("disk.bytes.free", du.BlocksFree, tags))
-		L = append(L, GaugeValue("disk.bytes.used", du.BlocksUsed, tags))
-		L = append(L, GaugeValue("disk.bytes.used.percent", du.BlocksUsedPercent, tags))
+		ret = append(ret, GaugeValue("disk.bytes.total", du.BlocksAll, tags))
+		ret = append(ret, GaugeValue("disk.bytes.free", du.BlocksFree, tags))
+		ret = append(ret, GaugeValue("disk.bytes.used", du.BlocksUsed, tags))
+		ret = append(ret, GaugeValue("disk.bytes.used.percent", du.BlocksUsedPercent, tags))
 
 		if du.InodesAll == 0 {
 			continue
 		}
 
-		L = append(L, GaugeValue("disk.inodes.total", du.InodesAll, tags))
-		L = append(L, GaugeValue("disk.inodes.free", du.InodesFree, tags))
-		L = append(L, GaugeValue("disk.inodes.used", du.InodesUsed, tags))
-		L = append(L, GaugeValue("disk.inodes.used.percent", du.InodesUsedPercent, tags))
+		ret = append(ret, GaugeValue("disk.inodes.total", du.InodesAll, tags))
+		ret = append(ret, GaugeValue("disk.inodes.free", du.InodesFree, tags))
+		ret = append(ret, GaugeValue("disk.inodes.used", du.InodesUsed, tags))
+		ret = append(ret, GaugeValue("disk.inodes.used.percent", du.InodesUsedPercent, tags))
 	}
 
-	if len(L) > 0 && diskTotal > 0 {
-		L = append(L, GaugeValue("disk.cap.bytes.total", float64(diskTotal)))
-		L = append(L, GaugeValue("disk.cap.bytes.used", float64(diskUsed)))
-		L = append(L, GaugeValue("disk.cap.bytes.free", float64(diskTotal-diskUsed)))
-		L = append(L, GaugeValue("disk.cap.bytes.used.percent", float64(diskUsed)*100.0/float64(diskTotal)))
+	if len(ret) > 0 && diskTotal > 0 {
+		ret = append(ret, GaugeValue("disk.cap.bytes.total", float64(diskTotal)))
+		ret = append(ret, GaugeValue("disk.cap.bytes.used", float64(diskUsed)))
+		ret = append(ret, GaugeValue("disk.cap.bytes.free", float64(diskTotal-diskUsed)))
+		ret = append(ret, GaugeValue("disk.cap.bytes.used.percent", float64(diskUsed)*100.0/float64(diskTotal)))
 	}
 
-	return
+	return ret
 }
 
 func hasIgnorePrefix(fsFile string, ignoreMountPointsPrefix []string) bool {

src/modules/collector/sys/funcs/diskstat.go

@@ -97,7 +97,9 @@ func IODelta(device string, f func([2]*nux.DiskStats) uint64) uint64 {
 	return f(val)
 }
 
-func IOStatsMetrics() (L []*dataobj.MetricValue) {
+func IOStatsMetrics() []*dataobj.MetricValue {
+	ret := make([]*dataobj.MetricValue, 0)
+
 	dsLock.RLock()
 	defer dsLock.RUnlock()
 
@@ -109,38 +111,38 @@ func IOStatsMetrics() (L []*dataobj.MetricValue) {
 		tags := "device=" + device
 		rio := IODelta(device, IOReadRequests)
 		wio := IODelta(device, IOWriteRequests)
-		delta_rsec := IODelta(device, IOReadSectors)
-		delta_wsec := IODelta(device, IOWriteSectors)
+		deltaRsec := IODelta(device, IOReadSectors)
+		deltaWsec := IODelta(device, IOWriteSectors)
 		ruse := IODelta(device, IOMsecRead)
 		wuse := IODelta(device, IOMsecWrite)
 		use := IODelta(device, IOMsecTotal)
-		n_io := rio + wio
-		avgrq_sz := 0.0
+		nio := rio + wio
+		avgrqSz := 0.0
 		await := 0.0
 		svctm := 0.0
-		if n_io != 0 {
-			avgrq_sz = float64(delta_rsec+delta_wsec) / float64(n_io)
-			await = float64(ruse+wuse) / float64(n_io)
-			svctm = float64(use) / float64(n_io)
+		if nio != 0 {
+			avgrqSz = float64(deltaRsec+deltaWsec) / float64(nio)
+			await = float64(ruse+wuse) / float64(nio)
+			svctm = float64(use) / float64(nio)
 		}
 
 		duration := IODelta(device, TS)
-		L = append(L, GaugeValue("disk.io.read.request", float64(rio), tags))
-		L = append(L, GaugeValue("disk.io.write.request", float64(wio), tags))
-		L = append(L, GaugeValue("disk.io.read.bytes", float64(delta_rsec)*512.0, tags))
-		L = append(L, GaugeValue("disk.io.write.bytes", float64(delta_wsec)*512.0, tags))
-		L = append(L, GaugeValue("disk.io.avgrq_sz", avgrq_sz, tags))
-		L = append(L, GaugeValue("disk.io.avgqu_sz", float64(IODelta(device, IOMsecWeightedTotal))/1000.0, tags))
-		L = append(L, GaugeValue("disk.io.await", await, tags))
-		L = append(L, GaugeValue("disk.io.svctm", svctm, tags))
+		ret = append(ret, GaugeValue("disk.io.read.request", float64(rio), tags))
+		ret = append(ret, GaugeValue("disk.io.write.request", float64(wio), tags))
+		ret = append(ret, GaugeValue("disk.io.read.bytes", float64(deltaRsec)*512.0, tags))
+		ret = append(ret, GaugeValue("disk.io.write.bytes", float64(deltaWsec)*512.0, tags))
+		ret = append(ret, GaugeValue("disk.io.avgrq_sz", avgrqSz, tags))
+		ret = append(ret, GaugeValue("disk.io.avgqu_sz", float64(IODelta(device, IOMsecWeightedTotal))/1000.0, tags))
+		ret = append(ret, GaugeValue("disk.io.await", await, tags))
+		ret = append(ret, GaugeValue("disk.io.svctm", svctm, tags))
 		tmp := float64(use) * 100.0 / float64(duration)
 		if tmp > 100.0 {
 			tmp = 100.0
 		}
-		L = append(L, GaugeValue("disk.io.util", tmp, tags))
+		ret = append(ret, GaugeValue("disk.io.util", tmp, tags))
 	}
 
-	return
+	return ret
 }
 
 func ShouldHandleDevice(device string) bool {

src/modules/collector/sys/funcs/fsstat.go

@@ -15,11 +15,13 @@ import (
 	"github.com/toolkits/pkg/nux"
 )
 
-func FsRWMetrics() (L []*dataobj.MetricValue) {
+func FsRWMetrics() []*dataobj.MetricValue {
+	ret := make([]*dataobj.MetricValue, 0)
+
 	mountPoints, err := nux.ListMountPoint()
 	if err != nil {
-		logger.Error("failed to call ListMountPoint:", err)
-		return
+		logger.Errorf("failed to call ListMountPoint:%v\n", err)
+		return ret
 	}
 
 	fsFileFilter := make(map[string]struct{}) //过滤 /proc/mounts 出现重复的fsFile
@@ -50,14 +52,14 @@ func FsRWMetrics() (L []*dataobj.MetricValue) {
 		f, err := os.Open(du.FsFile)
 		if err != nil {
 			logger.Error("target mount point open failed:", err)
-			L = append(L, GaugeValue("disk.rw.error", 1, tags))
+			ret = append(ret, GaugeValue("disk.rw.error", 1, tags))
 			continue
 		}
 
 		fs, err := f.Stat()
 		if err != nil {
 			logger.Error("get target mount point status failed:", err)
-			L = append(L, GaugeValue("disk.rw.error", 2, tags))
+			ret = append(ret, GaugeValue("disk.rw.error", 2, tags))
 			continue
 		}
 
@@ -70,13 +72,13 @@ func FsRWMetrics() (L []*dataobj.MetricValue) {
 		content := "FS-RW" + now
 		err = CheckFS(file, content)
 		if err != nil {
-			L = append(L, GaugeValue("disk.rw.error", 3, tags))
+			ret = append(ret, GaugeValue("disk.rw.error", 3, tags))
 		} else {
-			L = append(L, GaugeValue("disk.rw.error", 0, tags))
+			ret = append(ret, GaugeValue("disk.rw.error", 0, tags))
 		}
 	}
 
-	return
+	return ret
 }
 
 func CheckFS(file string, content string) error {
@@ -101,7 +103,7 @@ func CheckFS(file string, content string) error {
 	}
 	if string(read) != content {
 		logger.Error("Read content failed: ", string(read))
-		return errors.New("Read content failed")
+		return errors.New("read content failed")
 	}
 	//clean the file
 	err = os.Remove(file)

src/modules/collector/sys/funcs/netfilter.go

@@ -14,7 +14,7 @@ func NfMetrics() []*dataobj.MetricValue {
 	if !file.IsExist(connMaxFile) {
 		return []*dataobj.MetricValue{}
 	}
-	res := []*dataobj.MetricValue{}
+	var res []*dataobj.MetricValue
 
 	nfConntrackMax, err := file.ToInt64(connMaxFile)
 	if err != nil {

src/modules/collector/sys/funcs/ntp.go

@@ -12,10 +12,12 @@ import (
 
 var ntpServer string
 
-func NtpOffsetMetrics() (L []*dataobj.MetricValue) {
+func NtpOffsetMetrics() []*dataobj.MetricValue {
+	ret := make([]*dataobj.MetricValue, 0)
+
 	ntpServers := sys.Config.NtpServers
-	if len(ntpServers) <= 0 {
-		return
+	if len(ntpServers) == 0 {
+		return ret
 	}
 
 	for idx, server := range ntpServers {
@@ -42,15 +44,11 @@ func NtpOffsetMetrics() (L []*dataobj.MetricValue) {
 		logger.Debug("ntp: client receive time, ", dstTime)
 
 		delta := duration / 1e6 // 转换成 ms
-		L = append(L, GaugeValue("sys.ntp.offset.ms", delta))
-		//one ntp server's response is enough
+		ret = append(ret, GaugeValue("sys.ntp.offset.ms", delta))
 
-		return
+		//one ntp server's response is enough
+		break
 	}
 
-	//keep silence when no config ntp server
-	if len(ntpServers) > 0 {
-		logger.Error("sys.ntp.offset error. all ntp servers response failed.")
-	}
-	return
+	return ret
 }

src/modules/collector/sys/funcs/push.go

@@ -68,10 +68,10 @@ func Push(metricItems []*dataobj.MetricValue) error {
 
 		retry += 1
 		if retry == 3 {
-			retry = 0
 			break
 		}
 	}
+
 	return err
 }
 
@@ -84,14 +84,14 @@ func rpcCall(addr string, items []*dataobj.MetricValue) (dataobj.TransferResp, e
 		client, err = rpcClient(addr)
 		if err != nil {
 			return reply, err
-		} else {
-			affected := rpcClients.Put(addr, client)
-			if !affected {
-				defer func() {
-					// 我尝试把自己这个client塞进map失败，说明已经有一个client塞进去了，那我自己用完了就关闭
-					client.Close()
-				}()
-			}
+		}
+		affected := rpcClients.Put(addr, client)
+		if !affected {
+			defer func() {
+				// 我尝试把自己这个client塞进map失败，说明已经有一个client塞进去了，那我自己用完了就关闭
+				client.Close()
+			}()
+
 		}
 	}
 
@@ -105,7 +105,7 @@ func rpcCall(addr string, items []*dataobj.MetricValue) (dataobj.TransferResp, e
 
 	select {
 	case <-time.After(timeout):
-		logger.Warningf("rpc call timeout, transfer addr: %s", addr)
+		logger.Warningf("rpc call timeout, transfer addr: %s\n", addr)
 		rpcClients.Put(addr, nil)
 		client.Close()
 		return reply, fmt.Errorf("%s rpc call timeout", addr)

src/modules/collector/sys/funcs/sockstas.go

@@ -7,16 +7,17 @@ import (
 	"github.com/didi/nightingale/src/dataobj"
 )
 
-func SocketStatSummaryMetrics() (L []*dataobj.MetricValue) {
+func SocketStatSummaryMetrics() []*dataobj.MetricValue {
+	ret := make([]*dataobj.MetricValue, 0)
 	ssMap, err := nux.SocketStatSummary()
 	if err != nil {
-		logger.Error("failed to collect SocketStatSummaryMetrics:", err)
-		return
+		logger.Errorf("failed to collect SocketStatSummaryMetrics:%v\n", err)
+		return ret
 	}
 
 	for k, v := range ssMap {
-		L = append(L, GaugeValue("net."+k, v))
+		ret = append(ret, GaugeValue("net."+k, v))
 	}
 
-	return
+	return ret
 }

src/modules/collector/sys/funcs/sys.go

@@ -12,25 +12,26 @@ import (
 	"github.com/didi/nightingale/src/dataobj"
 )
 
-func FsKernelMetrics() (L []*dataobj.MetricValue) {
+func FsKernelMetrics() []*dataobj.MetricValue {
 	maxFiles, err := nux.KernelMaxFiles()
 	if err != nil {
-		logger.Error("failed collect kernel metrics:", err)
-		return
+		logger.Errorf("failed to call collect KernelMaxFiles:%v\n", err)
+		return nil
 	}
 
 	allocateFiles, err := nux.KernelAllocateFiles()
 	if err != nil {
-		logger.Error("failed to call KernelAllocateFiles:", err)
-		return
+		logger.Errorf("failed to call KernelAllocateFiles:%v\n", err)
+		return nil
 	}
 
 	v := math.Ceil(float64(allocateFiles) * 100 / float64(maxFiles))
-	L = append(L, GaugeValue("sys.fs.files.max", maxFiles))
-	L = append(L, GaugeValue("sys.fs.files.free", maxFiles-allocateFiles))
-	L = append(L, GaugeValue("sys.fs.files.used", allocateFiles))
-	L = append(L, GaugeValue("sys.fs.files.used.percent", v))
-	return
+	return []*dataobj.MetricValue{
+		GaugeValue("sys.fs.files.max", maxFiles),
+		GaugeValue("sys.fs.files.free", maxFiles-allocateFiles),
+		GaugeValue("sys.fs.files.used", allocateFiles),
+		GaugeValue("sys.fs.files.used.percent", v),
+	}
 }
 
 func ProcsNumMetrics() []*dataobj.MetricValue {