Add ability to test drive speeds on a MinIO setup (#7664)

- Extends existing Admin API to measure disk performance

pkg/disk/disk.go

@@ -1,5 +1,5 @@
 /*
- * MinIO Cloud Storage, (C) 2018 MinIO, Inc.
+ * MinIO Cloud Storage, (C) 2018-2019 MinIO, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,25 +17,9 @@
 package disk
 
 import (
-	"bytes"
-	"crypto/rand"
-	"errors"
 	"os"
-	"path"
-	"strconv"
-	"time"
 
-	humanize "github.com/dustin/go-humanize"
-)
-
-// file size for performance read and write checks
-const (
-	randBufSize = 1 * humanize.KiByte
-	randParts   = 1024
-	fileSize    = randParts * randBufSize
-
-	// Total count of read / write iteration for performance measurement
-	iterations = 10
+	"github.com/ncw/directio"
 )
 
 // Info stat fs struct is container which holds following values
@@ -64,9 +48,9 @@ type Performance struct {
 }
 
 // GetPerformance returns given disk's read and write performance
-func GetPerformance(path string) Performance {
+func GetPerformance(path string, size int64) Performance {
 	perf := Performance{}
-	write, read, err := doPerfMeasure(path)
+	write, read, err := doPerfMeasure(path, size)
 	if err != nil {
 		perf.Error = err.Error()
 		return perf
@@ -78,63 +62,36 @@ func GetPerformance(path string) Performance {
 
 // Calculate the write and read performance - write and read 10 tmp (1 MiB)
 // files and find the average time taken (Bytes / Sec)
-func doPerfMeasure(fsPath string) (write, read float64, err error) {
-	var count int
-	var totalWriteElapsed time.Duration
-	var totalReadElapsed time.Duration
-
+func doPerfMeasure(fsPath string, size int64) (writeSpeed, readSpeed float64, err error) {
+	// Remove the file created for speed test purposes
 	defer os.RemoveAll(fsPath)
 
-	randBuf := make([]byte, randBufSize)
-	rand.Read(randBuf)
-	buf := bytes.Repeat(randBuf, randParts)
-
-	// create the enclosing directory
-	err = os.MkdirAll(fsPath, 0777)
+	// Create a file with O_DIRECT flag
+	w, err := OpenFileDirectIO(fsPath, os.O_CREATE|os.O_WRONLY|os.O_EXCL, 0666)
 	if err != nil {
 		return 0, 0, err
 	}
 
-	for count = 1; count <= iterations; count++ {
-		fsTempObjPath := path.Join(fsPath, strconv.Itoa(count))
+	// Fetch aligned buf for direct-io
+	buf := directio.AlignedBlock(speedTestBlockSize)
 
-		// Write performance calculation
-		writeStart := time.Now()
-		n, err := writeFile(fsTempObjPath, buf)
-
-		if err != nil {
-			return 0, 0, err
-		}
-		if n != fileSize {
-			return 0, 0, errors.New("Could not write temporary data to disk")
-		}
-
-		writeElapsed := time.Since(writeStart)
-		totalWriteElapsed += writeElapsed
-
-		// Read performance calculation
-		readStart := time.Now()
-		n, err = readFile(fsTempObjPath, buf)
-
-		if err != nil {
-			return 0, 0, err
-		}
-		if n != fileSize {
-			return 0, 0, errors.New("Could not read temporary data from disk")
-		}
-
-		readElapsed := time.Since(readStart)
-		totalReadElapsed += readElapsed
+	writeSpeed, err = speedTestWrite(w, buf, size)
+	w.Close()
+	if err != nil {
+		return 0, 0, err
 	}
-	// Average time spent = total time elapsed / number of writes
-	avgWriteTime := totalWriteElapsed.Seconds() / float64(count)
-	// Write perf = fileSize (in Bytes) / average time spent writing (in seconds)
-	write = fileSize / avgWriteTime
 
-	// Average time spent = total time elapsed / number of writes
-	avgReadTime := totalReadElapsed.Seconds() / float64(count)
-	// read perf = fileSize (in Bytes) / average time spent reading (in seconds)
-	read = fileSize / avgReadTime
+	// Open file to compute read speed
+	r, err := OpenFileDirectIO(fsPath, os.O_RDONLY, 0666)
+	if err != nil {
+		return 0, 0, err
+	}
+	defer r.Close()
 
-	return write, read, nil
+	readSpeed, err = speedTestRead(r, buf, size)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	return writeSpeed, readSpeed, nil
 }

pkg/disk/helpers.go

@@ -1,52 +0,0 @@
-/*
- * MinIO Cloud Storage, (C) 2018 MinIO, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package disk
-
-import (
-	"os"
-)
-
-func readFile(path string, buf []byte) (int, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return 0, err
-	}
-	defer f.Close()
-
-	n, err := f.Read(buf)
-	if err != nil {
-		return 0, err
-	}
-
-	return n, nil
-}
-
-func writeFile(path string, data []byte) (int, error) {
-	f, err := os.Create(path)
-	if err != nil {
-		return 0, err
-	}
-	defer f.Close()
-
-	n, err := f.Write(data)
-	if err != nil {
-		return 0, err
-	}
-
-	f.Sync()
-	return n, nil
-}

pkg/disk/speedtest.go

@@ -0,0 +1,97 @@
+/*
+ * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package disk
+
+import (
+	"io"
+	"math"
+	"time"
+
+	humanize "github.com/dustin/go-humanize"
+)
+
+var speedTestBlockSize = 4 * humanize.MiByte
+
+// speedTestWrite computes the write speed by writing
+// `speedTestFileSize` bytes of data to `w` in 4MiB direct-aligned
+// blocks present in `buf`
+func speedTestWrite(w io.Writer, buf []byte, size int64) (float64, error) {
+	// Write speedTestFileSize of data and record write speed
+	startTime := time.Now()
+	remaining := size
+	for remaining > 0 {
+		var toWrite int
+		// there's more remaining to write than the buffer can hold
+		if int64(len(buf)) < remaining {
+			toWrite = len(buf)
+		} else { // buffer can hold all there is to write
+			toWrite = int(remaining)
+		}
+
+		written, err := w.Write(buf[:toWrite])
+		if err != nil {
+			return 0, err
+		}
+
+		remaining = remaining - int64(written)
+	}
+
+	elapsedTime := time.Since(startTime).Seconds()
+	totalWriteMBs := float64(size) / humanize.MiByte
+	writeSpeed := totalWriteMBs / elapsedTime
+
+	return roundToTwoDecimals(writeSpeed), nil
+}
+
+// speedTestRead computes the read speed by reading
+// `speedTestFileSize` bytes from the reader `r` using 4MiB size `buf`
+func speedTestRead(r io.Reader, buf []byte, size int64) (float64, error) {
+	// Read speedTestFileSize and record read speed
+	startTime := time.Now()
+	remaining := size
+	for remaining > 0 {
+		// reads `speedTestBlockSize` on every read
+		n, err := io.ReadFull(r, buf)
+		if err == io.ErrUnexpectedEOF || err == nil {
+			remaining = remaining - int64(n)
+			continue
+		}
+
+		// Nothing more left to read from the Reader
+		if err == io.EOF {
+			break
+		}
+		// Error while reading from the underlying Reader
+		if err != nil {
+			return 0, err
+		}
+	}
+
+	if remaining > 0 {
+		return 0, io.ErrUnexpectedEOF
+	}
+
+	elapsedTime := time.Since(startTime).Seconds()
+	totalReadMBs := float64(size) / humanize.MiByte
+	readSpeed := totalReadMBs / elapsedTime
+
+	return roundToTwoDecimals(readSpeed), nil
+}
+
+func roundToTwoDecimals(num float64) float64 {
+	return math.Round(num*100) / 100
+}

pkg/madmin/examples/drives-perf-info.go

@@ -36,7 +36,7 @@ func main() {
 		log.Fatalln(err)
 	}
 
-	st, err := madmClnt.ServerDrivesPerfInfo()
+	st, err := madmClnt.ServerDrivesPerfInfo(madmin.DefaultDrivePerfSize)
 	if err != nil {
 		log.Fatalln(err)
 	}

pkg/madmin/info-commands.go

@@ -35,6 +35,8 @@ import (
 const (
 	// DefaultNetPerfSize - default payload size used for network performance.
 	DefaultNetPerfSize = 100 * humanize.MiByte
+	// DefaultDrivePerfSize - default file size for testing drive performance
+	DefaultDrivePerfSize = 100 * humanize.MiByte
 )
 
 // BackendType - represents different backend types.
@@ -172,12 +174,16 @@ type ServerDrivesPerfInfo struct {
 	Addr  string             `json:"addr"`
 	Error string             `json:"error,omitempty"`
 	Perf  []disk.Performance `json:"perf"`
+	Size  int64              `json:"size,omitempty"`
 }
 
 // ServerDrivesPerfInfo - Returns drive's read and write performance information
-func (adm *AdminClient) ServerDrivesPerfInfo() ([]ServerDrivesPerfInfo, error) {
+func (adm *AdminClient) ServerDrivesPerfInfo(size int64) ([]ServerDrivesPerfInfo, error) {
 	v := url.Values{}
 	v.Set("perfType", string("drive"))
+
+	v.Set("size", strconv.FormatInt(size, 10))
+
 	resp, err := adm.executeMethod("GET", requestData{
 		relPath:     "/v1/performance",
 		queryValues: v,