github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/libraries/doltcore/remotestorage/stats.go (about)

     1  // Copyright 2019 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package remotestorage
    16  
    17  import (
    18  	"fmt"
    19  	"io"
    20  	"os"
    21  	"sync"
    22  	"time"
    23  
    24  	"github.com/HdrHistogram/hdrhistogram-go"
    25  	"github.com/fatih/color"
    26  )
    27  
    28  var StatsFactory func() StatsRecorder = NullStatsRecorderFactory
    29  var StatsFlusher func(StatsRecorder) = func(StatsRecorder) {}
    30  
    31  func NullStatsRecorderFactory() StatsRecorder {
    32  	return NullStatsRecorder{}
    33  }
    34  
    35  func HistogramStatsRecorderFactory() StatsRecorder {
    36  	return NewHistorgramStatsRecorder()
    37  }
    38  
    39  func StatsFlusherToColorError(r StatsRecorder) {
    40  	r.WriteSummaryTo(color.Error)
    41  }
    42  
    43  func init() {
    44  	if _, ok := os.LookupEnv("DOLT_REMOTE_VERBOSE_DOWNLOAD_STATS"); ok {
    45  		StatsFactory = HistogramStatsRecorderFactory
    46  		StatsFlusher = StatsFlusherToColorError
    47  	}
    48  }
    49  
    50  type StatsRecorder interface {
    51  	RecordTimeToFirstByte(hedge, retry int, size uint64, d time.Duration)
    52  	RecordDownloadAttemptStart(hedge, retry int, offset, size uint64)
    53  	RecordDownloadComplete(hedge, retry int, size uint64, d time.Duration)
    54  	WriteSummaryTo(io.Writer) error
    55  }
    56  
    57  var _ StatsRecorder = NullStatsRecorder{}
    58  
    59  type NullStatsRecorder struct {
    60  }
    61  
    62  func (NullStatsRecorder) RecordTimeToFirstByte(hedge, retry int, size uint64, d time.Duration) {
    63  }
    64  
    65  func (NullStatsRecorder) RecordDownloadAttemptStart(hedge, retry int, offset, size uint64) {
    66  }
    67  
    68  func (NullStatsRecorder) RecordDownloadComplete(hedge, retry int, size uint64, d time.Duration) {
    69  }
    70  
    71  func (NullStatsRecorder) WriteSummaryTo(io.Writer) error {
    72  	return nil
    73  }
    74  
    75  type HistogramStatsRecorder struct {
    76  	mu                 *sync.Mutex
    77  	sizes              *hdrhistogram.Histogram
    78  	downloadTimeMillis *hdrhistogram.Histogram
    79  	firstByteMillis    *hdrhistogram.Histogram
    80  	retryCount         int
    81  	hedgeCount         int
    82  	hedgeCompleteCount int
    83  }
    84  
    85  func NewHistorgramStatsRecorder() *HistogramStatsRecorder {
    86  	return &HistogramStatsRecorder{
    87  		new(sync.Mutex),
    88  		hdrhistogram.New(128, 4294967296, 3), // 128 bytes - 4 GB
    89  		hdrhistogram.New(10, 3600000, 3),     // 10 ms - 1 hr
    90  		hdrhistogram.New(10, 300000, 3),      // 10 ms - 5 mins
    91  		0,
    92  		0,
    93  		0,
    94  	}
    95  }
    96  
    97  func (r *HistogramStatsRecorder) RecordTimeToFirstByte(hedge, retry int, size uint64, d time.Duration) {
    98  	r.mu.Lock()
    99  	defer r.mu.Unlock()
   100  	r.firstByteMillis.RecordValue(int64(d / time.Millisecond))
   101  }
   102  
   103  func (r *HistogramStatsRecorder) RecordDownloadAttemptStart(hedge, retry int, offset, size uint64) {
   104  	if hedge == 1 && retry == 0 {
   105  		r.mu.Lock()
   106  		defer r.mu.Unlock()
   107  		r.sizes.RecordValue(int64(size))
   108  	}
   109  	if retry > 0 {
   110  		r.mu.Lock()
   111  		defer r.mu.Unlock()
   112  		r.retryCount += 1
   113  	} else if hedge > 1 {
   114  		r.mu.Lock()
   115  		defer r.mu.Unlock()
   116  		r.hedgeCount += 1
   117  	}
   118  }
   119  
   120  func (r *HistogramStatsRecorder) RecordDownloadComplete(hedge, retry int, size uint64, d time.Duration) {
   121  	r.mu.Lock()
   122  	defer r.mu.Unlock()
   123  	r.downloadTimeMillis.RecordValue(int64(d / time.Millisecond))
   124  	if hedge > 1 {
   125  		r.hedgeCompleteCount += 1
   126  	}
   127  }
   128  
   129  func (r *HistogramStatsRecorder) WriteSummaryTo(w io.Writer) error {
   130  	r.mu.Lock()
   131  	defer r.mu.Unlock()
   132  	_, err := fmt.Fprintf(w, "total downloads: %d, retries: %d, hedges: %d, completed hedges: %d\n",
   133  		r.sizes.TotalCount(), r.retryCount, r.hedgeCount, r.hedgeCompleteCount)
   134  	if err != nil {
   135  		return err
   136  	}
   137  	err = writeHistogram(w, "sizes (bytes)", r.sizes)
   138  	if err != nil {
   139  		return err
   140  	}
   141  	err = writeHistogram(w, "time to first byte (millis)", r.firstByteMillis)
   142  	if err != nil {
   143  		return err
   144  	}
   145  	err = writeHistogram(w, "download time (millis)", r.downloadTimeMillis)
   146  	if err != nil {
   147  		return err
   148  	}
   149  	return nil
   150  }
   151  
   152  func writeHistogram(w io.Writer, prefix string, h *hdrhistogram.Histogram) error {
   153  	_, err := fmt.Fprintf(w, "%s: p50: %d, p90: %d, p99: %d, avg: %.2f, max: %d\n", prefix,
   154  		h.ValueAtQuantile(50), h.ValueAtQuantile(90), h.ValueAtQuantile(99), h.Mean(), h.Max())
   155  	return err
   156  }