SD-1123 Collect disk IO stats on Linux

scalingdata · Apr 22, 2015 · 9608cd4 · 9608cd4
1 parent 81b043e
commit 9608cd4
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Showing 6 changed files with 189 additions and 1 deletion.
diff --git a/fakes/fake_sigar.go b/fakes/fake_sigar.go
@@ -3,7 +3,7 @@ package fakes
 import (
 	"time"
 
-	sigar "github.com/cloudfoundry/gosigar"
+	sigar "github.com/scalingdata//gosigar"
 )
 
 type FakeSigar struct {

diff --git a/sigar_darwin.go b/sigar_darwin.go
@@ -192,6 +192,10 @@ func (self *FileSystemList) Get() error {
 	return err
 }
 
+func (self *DiskList) Get() error {
+	return notImplemented()
+}
+
 func (self *ProcList) Get() error {
 	n := C.proc_listpids(C.PROC_ALL_PIDS, 0, nil, 0)
 	if n <= 0 {
@@ -465,3 +469,8 @@ func task_info(pid int, info *C.struct_proc_taskallinfo) error {
 
 	return nil
 }
+
+func notImplemented() error {
+	panic("Not Implemented")
+	return nil
+}
diff --git a/sigar_interface.go b/sigar_interface.go
@@ -141,3 +141,29 @@ type ProcExe struct {
 	Cwd  string
 	Root string
 }
+
+type DiskList struct {
+	List map[string]DiskIo
+}
+
+type DiskIo struct {
+	ReadOps uint64
+	ReadBytes uint64
+	ReadTimeMs uint64
+	WriteOps uint64
+	WriteBytes uint64
+	WriteTimeMs uint64
+	IoTimeMs uint64
+}
+
+func (self DiskIo) Delta(other DiskIo) DiskIo {
+	return DiskIo {
+		ReadOps: self.ReadOps - other.ReadOps,
+		ReadBytes: self.ReadBytes - other.ReadBytes,
+		ReadTimeMs: self.ReadTimeMs - other.ReadTimeMs,
+		WriteOps: self.WriteOps - other.WriteOps,
+		WriteBytes: self.WriteBytes - other.WriteBytes,
+		WriteTimeMs: self.WriteTimeMs - other.WriteTimeMs,
+		IoTimeMs: self.IoTimeMs - other.IoTimeMs,
+	}
+}
diff --git a/sigar_linux.go b/sigar_linux.go
@@ -155,6 +155,58 @@ func (self *FileSystemList) Get() error {
 	return err
 }
 
+func (self *DiskList) Get() error {
+	/* List all the partitions, and check the major/minor device ID
+	   to find which are devices vs. partitions (ex. sda v. sda1) */
+	devices := make(map[string]bool)
+	diskList := make(map[string]DiskIo)
+	err := readFile(Procd+"/partitions", func(line string) bool {
+		fields := strings.Fields(line)
+		if len(fields) < 4 {
+			return true
+		}
+		majorDevId, err := strtoull(fields[0])
+		if err != nil {
+			return true
+		}
+		minorDevId, err := strtoull(fields[1])
+		if err != nil {
+			return true
+		}
+		if isNotPartition(majorDevId, minorDevId) {
+			devices[fields[3]] = true
+		}
+		return true
+	})
+
+	/* Get all device stats from /proc/diskstats and filter by
+	   devices from /proc/partitions */
+	err = readFile(Procd+"/diskstats", func(line string) bool {
+		fields := strings.Fields(line)
+		if len(fields) < 13 {
+			return true
+		}
+		deviceName := fields[2]
+		if _, ok := devices[deviceName]; !ok {
+			return true
+		}
+		io := DiskIo {}
+		io.ReadOps, _ = strtoull(fields[3])
+		readBytes, _ := strtoull(fields[5])
+		io.ReadBytes = readBytes * 512
+		io.ReadTimeMs, _ = strtoull(fields[6])
+		io.WriteOps, _ = strtoull(fields[7])
+		writeBytes, _ := strtoull(fields[9])
+		io.WriteBytes = writeBytes * 512
+		io.WriteTimeMs, _ = strtoull(fields[10])
+		io.IoTimeMs, _ = strtoull(fields[12])
+		diskList[deviceName] = io
+		return true
+	})
+	self.List = diskList
+	return err
+}
+
 func (self *ProcList) Get() error {
 	dir, err := os.Open(Procd)
 	if err != nil {
@@ -388,3 +440,21 @@ func readProcFile(pid int, name string) ([]byte, error) {
 
 	return contents, err
 }
+
+/* For SCSI and IDE devices, only display devices and not individual partitions.
+   For other major numbers, show all devices regardless of minor (for LVM, for example).
+   As described here: http://www.linux-tutorial.info/modules.php?name=MContent&pageid=94 */
+func isNotPartition(majorDevId, minorDevId uint64) bool {
+	if majorDevId == 3 || majorDevId == 22 ||        // IDE0_MAJOR IDE1_MAJOR
+		majorDevId == 33 || majorDevId == 34 ||  // IDE2_MAJOR IDE3_MAJOR
+		majorDevId == 56 || majorDevId == 57 ||  // IDE4_MAJOR IDE5_MAJOR
+		(majorDevId >= 88 && majorDevId <= 91) { // IDE6_MAJOR to IDE_IDE9_MAJOR
+		return (minorDevId & 0x3F) == 0 // IDE uses bottom 10 bits for partitions
+	}
+	if majorDevId == 8 || // SCSI_DISK0_MAJOR 
+		(majorDevId >= 65 && majorDevId <= 71) ||  // SCSI_DISK1_MAJOR to SCSI_DISK7_MAJOR
+		(majorDevId >= 128 && majorDevId <= 135) { // SCSI_DISK8_MAJOR to SCSI_DISK15_MAJOR
+		return (minorDevId & 0x0F) == 0 // SCSI uses bottom 8 bits for partitions
+	}
+	return true
+}
diff --git a/sigar_linux_test.go b/sigar_linux_test.go
@@ -280,4 +280,83 @@ DirectMap2M:      333824 kB
 			Expect(swap.Free).To(BeNumerically("==", 786428*1024))
 		})
 	})
+
+	Describe("DiskIO", func() {
+		var diskstatFile string
+		var partitionsFile string
+		BeforeEach(func() {
+			partitionsFile = procd + "/partitions"
+			partitionsContents := `
+major minor  #blocks  name
+
+   8        0   41943040 sda
+   8        1     512000 sda1
+   8        2   41430016 sda2
+ 253        0   40476672 dm-0
+ 253        1     950272 dm-1
+` 
+			diskstatFile = procd + "/diskstats"
+			diskstatContents := `
+   1       0 ram0 0 0 0 0 0 0 0 0 0 0 0
+   1       1 ram1 0 0 0 0 0 0 0 0 0 0 0
+   1       2 ram2 0 0 0 0 0 0 0 0 0 0 0
+   1       3 ram3 0 0 0 0 0 0 0 0 0 0 0
+   1       4 ram4 0 0 0 0 0 0 0 0 0 0 0
+   1       5 ram5 0 0 0 0 0 0 0 0 0 0 0
+   1       6 ram6 0 0 0 0 0 0 0 0 0 0 0
+   1       7 ram7 0 0 0 0 0 0 0 0 0 0 0
+   1       8 ram8 0 0 0 0 0 0 0 0 0 0 0
+   1       9 ram9 0 0 0 0 0 0 0 0 0 0 0
+   1      10 ram10 0 0 0 0 0 0 0 0 0 0 0
+   1      11 ram11 0 0 0 0 0 0 0 0 0 0 0
+   1      12 ram12 0 0 0 0 0 0 0 0 0 0 0
+   1      13 ram13 0 0 0 0 0 0 0 0 0 0 0
+   1      14 ram14 0 0 0 0 0 0 0 0 0 0 0
+   1      15 ram15 0 0 0 0 0 0 0 0 0 0 0
+   7       0 loop0 0 0 0 0 0 0 0 0 0 0 0
+   7       1 loop1 0 0 0 0 0 0 0 0 0 0 0
+   7       2 loop2 0 0 0 0 0 0 0 0 0 0 0
+   7       3 loop3 0 0 0 0 0 0 0 0 0 0 0
+   7       4 loop4 0 0 0 0 0 0 0 0 0 0 0
+   7       5 loop5 0 0 0 0 0 0 0 0 0 0 0
+   7       6 loop6 0 0 0 0 0 0 0 0 0 0 0
+   7       7 loop7 0 0 0 0 0 0 0 0 0 0 0
+   8       0 sda 7089 1514 243714 6329 86342 820181 7159936 1397746 0 50380 1404142
+   8       1 sda1 560 243 12192 133 64 5182 10504 955 0 218 1085
+   8       2 sda2 6375 1271 230290 6161 77130 814999 7149432 1395024 0 48563 1401264
+ 253       0 dm-0 7255 0 226842 8638 895753 0 7149432 40185506 0 50361 40194137
+ 253       1 dm-1 307 0 2456 116 0 0 0 0 0 116 116
+`		
+			err := ioutil.WriteFile(partitionsFile, []byte(partitionsContents), 0444)
+			Expect(err).ToNot(HaveOccurred()) 
+
+			err = ioutil.WriteFile(diskstatFile, []byte(diskstatContents), 0444)
+			Expect(err).ToNot(HaveOccurred()) 
+		})
+
+		It("skips non-block devices", func() {
+			ioStat := sigar.DiskList{}
+			err := ioStat.Get()
+			Expect(err).ToNot(HaveOccurred())
+
+			_, ok := ioStat.List["ram0"]
+			Expect(ok).To(Equal(false))
+			_, ok = ioStat.List["loop0"]
+			Expect(ok).To(Equal(false))
+		})
+
+		It("returns correct disk IO info", func() {
+			ioStat := sigar.DiskList{}
+			err := ioStat.Get()
+			Expect(err).ToNot(HaveOccurred())
+
+			Expect(ioStat.List["sda"].ReadOps).To(Equal(uint64(7089)))
+			Expect(ioStat.List["sda"].ReadBytes).To(Equal(uint64(243714 * 512)))
+			Expect(ioStat.List["sda"].ReadTimeMs).To(Equal(uint64(6329)))
+			Expect(ioStat.List["sda"].WriteOps).To(Equal(uint64(86342)))
+			Expect(ioStat.List["sda"].WriteBytes).To(Equal(uint64(7159936 * 512)))
+			Expect(ioStat.List["sda"].WriteTimeMs).To(Equal(uint64(1397746)))
+			Expect(ioStat.List["sda"].IoTimeMs).To(Equal(uint64(50380)))
+		})
+	})
 })
diff --git a/sigar_windows.go b/sigar_windows.go
@@ -52,6 +52,10 @@ func (self *FileSystemList) Get() error {
 	return notImplemented()
 }
 
+func (self *DiskList) Get() error {
+	return notImplemented()
+}
+
 func (self *ProcList) Get() error {
 	return notImplemented()
 }