blob: 4920d68324a388430b509a03fcbdcd40c07aae7c [file] [log] [blame]
Girish Gowdra64503432020-01-07 10:59:10 +05301package metrics
2
3import (
4 "runtime"
5 "strings"
6 "time"
7
8 "github.com/hashicorp/go-immutable-radix"
9)
10
11type Label struct {
12 Name string
13 Value string
14}
15
16func (m *Metrics) SetGauge(key []string, val float32) {
17 m.SetGaugeWithLabels(key, val, nil)
18}
19
20func (m *Metrics) SetGaugeWithLabels(key []string, val float32, labels []Label) {
21 if m.HostName != "" {
22 if m.EnableHostnameLabel {
23 labels = append(labels, Label{"host", m.HostName})
24 } else if m.EnableHostname {
25 key = insert(0, m.HostName, key)
26 }
27 }
28 if m.EnableTypePrefix {
29 key = insert(0, "gauge", key)
30 }
31 if m.ServiceName != "" {
32 if m.EnableServiceLabel {
33 labels = append(labels, Label{"service", m.ServiceName})
34 } else {
35 key = insert(0, m.ServiceName, key)
36 }
37 }
38 allowed, labelsFiltered := m.allowMetric(key, labels)
39 if !allowed {
40 return
41 }
42 m.sink.SetGaugeWithLabels(key, val, labelsFiltered)
43}
44
45func (m *Metrics) EmitKey(key []string, val float32) {
46 if m.EnableTypePrefix {
47 key = insert(0, "kv", key)
48 }
49 if m.ServiceName != "" {
50 key = insert(0, m.ServiceName, key)
51 }
52 allowed, _ := m.allowMetric(key, nil)
53 if !allowed {
54 return
55 }
56 m.sink.EmitKey(key, val)
57}
58
59func (m *Metrics) IncrCounter(key []string, val float32) {
60 m.IncrCounterWithLabels(key, val, nil)
61}
62
63func (m *Metrics) IncrCounterWithLabels(key []string, val float32, labels []Label) {
64 if m.HostName != "" && m.EnableHostnameLabel {
65 labels = append(labels, Label{"host", m.HostName})
66 }
67 if m.EnableTypePrefix {
68 key = insert(0, "counter", key)
69 }
70 if m.ServiceName != "" {
71 if m.EnableServiceLabel {
72 labels = append(labels, Label{"service", m.ServiceName})
73 } else {
74 key = insert(0, m.ServiceName, key)
75 }
76 }
77 allowed, labelsFiltered := m.allowMetric(key, labels)
78 if !allowed {
79 return
80 }
81 m.sink.IncrCounterWithLabels(key, val, labelsFiltered)
82}
83
84func (m *Metrics) AddSample(key []string, val float32) {
85 m.AddSampleWithLabels(key, val, nil)
86}
87
88func (m *Metrics) AddSampleWithLabels(key []string, val float32, labels []Label) {
89 if m.HostName != "" && m.EnableHostnameLabel {
90 labels = append(labels, Label{"host", m.HostName})
91 }
92 if m.EnableTypePrefix {
93 key = insert(0, "sample", key)
94 }
95 if m.ServiceName != "" {
96 if m.EnableServiceLabel {
97 labels = append(labels, Label{"service", m.ServiceName})
98 } else {
99 key = insert(0, m.ServiceName, key)
100 }
101 }
102 allowed, labelsFiltered := m.allowMetric(key, labels)
103 if !allowed {
104 return
105 }
106 m.sink.AddSampleWithLabels(key, val, labelsFiltered)
107}
108
109func (m *Metrics) MeasureSince(key []string, start time.Time) {
110 m.MeasureSinceWithLabels(key, start, nil)
111}
112
113func (m *Metrics) MeasureSinceWithLabels(key []string, start time.Time, labels []Label) {
114 if m.HostName != "" && m.EnableHostnameLabel {
115 labels = append(labels, Label{"host", m.HostName})
116 }
117 if m.EnableTypePrefix {
118 key = insert(0, "timer", key)
119 }
120 if m.ServiceName != "" {
121 if m.EnableServiceLabel {
122 labels = append(labels, Label{"service", m.ServiceName})
123 } else {
124 key = insert(0, m.ServiceName, key)
125 }
126 }
127 allowed, labelsFiltered := m.allowMetric(key, labels)
128 if !allowed {
129 return
130 }
131 now := time.Now()
132 elapsed := now.Sub(start)
133 msec := float32(elapsed.Nanoseconds()) / float32(m.TimerGranularity)
134 m.sink.AddSampleWithLabels(key, msec, labelsFiltered)
135}
136
137// UpdateFilter overwrites the existing filter with the given rules.
138func (m *Metrics) UpdateFilter(allow, block []string) {
139 m.UpdateFilterAndLabels(allow, block, m.AllowedLabels, m.BlockedLabels)
140}
141
142// UpdateFilterAndLabels overwrites the existing filter with the given rules.
143func (m *Metrics) UpdateFilterAndLabels(allow, block, allowedLabels, blockedLabels []string) {
144 m.filterLock.Lock()
145 defer m.filterLock.Unlock()
146
147 m.AllowedPrefixes = allow
148 m.BlockedPrefixes = block
149
150 if allowedLabels == nil {
151 // Having a white list means we take only elements from it
152 m.allowedLabels = nil
153 } else {
154 m.allowedLabels = make(map[string]bool)
155 for _, v := range allowedLabels {
156 m.allowedLabels[v] = true
157 }
158 }
159 m.blockedLabels = make(map[string]bool)
160 for _, v := range blockedLabels {
161 m.blockedLabels[v] = true
162 }
163 m.AllowedLabels = allowedLabels
164 m.BlockedLabels = blockedLabels
165
166 m.filter = iradix.New()
167 for _, prefix := range m.AllowedPrefixes {
168 m.filter, _, _ = m.filter.Insert([]byte(prefix), true)
169 }
170 for _, prefix := range m.BlockedPrefixes {
171 m.filter, _, _ = m.filter.Insert([]byte(prefix), false)
172 }
173}
174
175// labelIsAllowed return true if a should be included in metric
176// the caller should lock m.filterLock while calling this method
177func (m *Metrics) labelIsAllowed(label *Label) bool {
178 labelName := (*label).Name
179 if m.blockedLabels != nil {
180 _, ok := m.blockedLabels[labelName]
181 if ok {
182 // If present, let's remove this label
183 return false
184 }
185 }
186 if m.allowedLabels != nil {
187 _, ok := m.allowedLabels[labelName]
188 return ok
189 }
190 // Allow by default
191 return true
192}
193
194// filterLabels return only allowed labels
195// the caller should lock m.filterLock while calling this method
196func (m *Metrics) filterLabels(labels []Label) []Label {
197 if labels == nil {
198 return nil
199 }
200 toReturn := []Label{}
201 for _, label := range labels {
202 if m.labelIsAllowed(&label) {
203 toReturn = append(toReturn, label)
204 }
205 }
206 return toReturn
207}
208
209// Returns whether the metric should be allowed based on configured prefix filters
210// Also return the applicable labels
211func (m *Metrics) allowMetric(key []string, labels []Label) (bool, []Label) {
212 m.filterLock.RLock()
213 defer m.filterLock.RUnlock()
214
215 if m.filter == nil || m.filter.Len() == 0 {
216 return m.Config.FilterDefault, m.filterLabels(labels)
217 }
218
219 _, allowed, ok := m.filter.Root().LongestPrefix([]byte(strings.Join(key, ".")))
220 if !ok {
221 return m.Config.FilterDefault, m.filterLabels(labels)
222 }
223
224 return allowed.(bool), m.filterLabels(labels)
225}
226
227// Periodically collects runtime stats to publish
228func (m *Metrics) collectStats() {
229 for {
230 time.Sleep(m.ProfileInterval)
231 m.emitRuntimeStats()
232 }
233}
234
235// Emits various runtime statsitics
236func (m *Metrics) emitRuntimeStats() {
237 // Export number of Goroutines
238 numRoutines := runtime.NumGoroutine()
239 m.SetGauge([]string{"runtime", "num_goroutines"}, float32(numRoutines))
240
241 // Export memory stats
242 var stats runtime.MemStats
243 runtime.ReadMemStats(&stats)
244 m.SetGauge([]string{"runtime", "alloc_bytes"}, float32(stats.Alloc))
245 m.SetGauge([]string{"runtime", "sys_bytes"}, float32(stats.Sys))
246 m.SetGauge([]string{"runtime", "malloc_count"}, float32(stats.Mallocs))
247 m.SetGauge([]string{"runtime", "free_count"}, float32(stats.Frees))
248 m.SetGauge([]string{"runtime", "heap_objects"}, float32(stats.HeapObjects))
249 m.SetGauge([]string{"runtime", "total_gc_pause_ns"}, float32(stats.PauseTotalNs))
250 m.SetGauge([]string{"runtime", "total_gc_runs"}, float32(stats.NumGC))
251
252 // Export info about the last few GC runs
253 num := stats.NumGC
254
255 // Handle wrap around
256 if num < m.lastNumGC {
257 m.lastNumGC = 0
258 }
259
260 // Ensure we don't scan more than 256
261 if num-m.lastNumGC >= 256 {
262 m.lastNumGC = num - 255
263 }
264
265 for i := m.lastNumGC; i < num; i++ {
266 pause := stats.PauseNs[i%256]
267 m.AddSample([]string{"runtime", "gc_pause_ns"}, float32(pause))
268 }
269 m.lastNumGC = num
270}
271
272// Inserts a string value at an index into the slice
273func insert(i int, v string, s []string) []string {
274 s = append(s, "")
275 copy(s[i+1:], s[i:])
276 s[i] = v
277 return s
278}