-
Notifications
You must be signed in to change notification settings - Fork 116
/
http.go
275 lines (236 loc) · 7.47 KB
/
http.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
// Copyright 2022 The OpenZipkin Authors
//
// 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 http implements a HTTP reporter to send spans to Zipkin V2 collectors.
*/
package http
import (
"bytes"
"context"
"log"
"net/http"
"os"
"sync"
"time"
"github.com/openzipkin/zipkin-go/model"
"github.com/openzipkin/zipkin-go/reporter"
)
// defaults
const (
defaultTimeout = 5 * time.Second // timeout for http request in seconds
defaultBatchInterval = 1 * time.Second // BatchInterval in seconds
defaultBatchSize = 100
defaultMaxBacklog = 1000
)
// HTTPDoer will do a request to the Zipkin HTTP Collector
type HTTPDoer interface { // nolint: revive // keep as is, we don't want to break dependendants
Do(req *http.Request) (*http.Response, error)
}
// httpReporter will send spans to a Zipkin HTTP Collector using Zipkin V2 API.
type httpReporter struct {
url string
client HTTPDoer
logger *log.Logger
batchInterval time.Duration
batchSize int
maxBacklog int
batchMtx *sync.Mutex
batch []*model.SpanModel
spanC chan *model.SpanModel
sendC chan struct{}
quit chan struct{}
shutdown chan error
reqCallback RequestCallbackFn
reqTimeout time.Duration
serializer reporter.SpanSerializer
}
// Send implements reporter
func (r *httpReporter) Send(s model.SpanModel) {
r.spanC <- &s
}
// Close implements reporter
func (r *httpReporter) Close() error {
close(r.quit)
return <-r.shutdown
}
func (r *httpReporter) loop() {
var (
nextSend = time.Now().Add(r.batchInterval)
ticker = time.NewTicker(r.batchInterval / 10)
tickerChan = ticker.C
)
defer ticker.Stop()
for {
select {
case span := <-r.spanC:
currentBatchSize := r.append(span)
if currentBatchSize >= r.batchSize {
nextSend = time.Now().Add(r.batchInterval)
r.enqueueSend()
}
case <-tickerChan:
if time.Now().After(nextSend) {
nextSend = time.Now().Add(r.batchInterval)
r.enqueueSend()
}
case <-r.quit:
close(r.sendC)
return
}
}
}
func (r *httpReporter) sendLoop() {
for range r.sendC {
_ = r.sendBatch()
}
r.shutdown <- r.sendBatch()
}
func (r *httpReporter) enqueueSend() {
select {
case r.sendC <- struct{}{}:
default:
// Do nothing if there's a pending send request already
}
}
func (r *httpReporter) append(span *model.SpanModel) (newBatchSize int) {
r.batchMtx.Lock()
r.batch = append(r.batch, span)
if len(r.batch) > r.maxBacklog {
dispose := len(r.batch) - r.maxBacklog
r.logger.Printf("backlog too long, disposing %d spans", dispose)
r.batch = r.batch[dispose:]
}
newBatchSize = len(r.batch)
r.batchMtx.Unlock()
return
}
func (r *httpReporter) sendBatch() error {
// Select all current spans in the batch to be sent
r.batchMtx.Lock()
sendBatch := r.batch[:]
r.batchMtx.Unlock()
if len(sendBatch) == 0 {
return nil
}
body, err := r.serializer.Serialize(sendBatch)
if err != nil {
r.logger.Printf("failed when marshalling the spans batch: %s\n", err.Error())
return err
}
req, err := http.NewRequest("POST", r.url, bytes.NewReader(body))
if err != nil {
r.logger.Printf("failed when creating the request: %s\n", err.Error())
return err
}
// By default we send b3:0 header to mitigate trace reporting amplification in
// service mesh environments where the sidecar proxies might trace the call
// we do here towards the Zipkin collector.
req.Header.Set("b3", "0")
req.Header.Set("Content-Type", r.serializer.ContentType())
if r.reqCallback != nil {
r.reqCallback(req)
}
ctx, cancel := context.WithTimeout(req.Context(), r.reqTimeout)
defer cancel()
resp, err := r.client.Do(req.WithContext(ctx))
if err != nil {
r.logger.Printf("failed to send the request: %s\n", err.Error())
return err
}
_ = resp.Body.Close()
if resp.StatusCode < 200 || resp.StatusCode > 299 {
r.logger.Printf("failed the request with status code %d\n", resp.StatusCode)
}
// Remove sent spans from the batch even if they were not saved
r.batchMtx.Lock()
r.batch = r.batch[len(sendBatch):]
r.batchMtx.Unlock()
return nil
}
// RequestCallbackFn receives the initialized request from the Collector before
// sending it over the wire. This allows one to plug in additional headers or
// do other customization.
type RequestCallbackFn func(*http.Request)
// ReporterOption sets a parameter for the HTTP Reporter
type ReporterOption func(r *httpReporter)
// Timeout sets maximum timeout for the http request through its context.
func Timeout(duration time.Duration) ReporterOption {
return func(r *httpReporter) { r.reqTimeout = duration }
}
// BatchSize sets the maximum batch size, after which a collect will be
// triggered. The default batch size is 100 traces.
func BatchSize(n int) ReporterOption {
return func(r *httpReporter) { r.batchSize = n }
}
// MaxBacklog sets the maximum backlog size. When batch size reaches this
// threshold, spans from the beginning of the batch will be disposed.
func MaxBacklog(n int) ReporterOption {
return func(r *httpReporter) { r.maxBacklog = n }
}
// BatchInterval sets the maximum duration we will buffer traces before
// emitting them to the collector. The default batch interval is 1 second.
func BatchInterval(d time.Duration) ReporterOption {
return func(r *httpReporter) { r.batchInterval = d }
}
// Client sets a custom http client to use under the interface HTTPDoer
// which includes a `Do` method with same signature as the *http.Client
func Client(client HTTPDoer) ReporterOption {
return func(r *httpReporter) { r.client = client }
}
// RequestCallback registers a callback function to adjust the reporter
// *http.Request before it sends the request to Zipkin.
func RequestCallback(rc RequestCallbackFn) ReporterOption {
return func(r *httpReporter) { r.reqCallback = rc }
}
// Logger sets the logger used to report errors in the collection
// process.
func Logger(l *log.Logger) ReporterOption {
return func(r *httpReporter) { r.logger = l }
}
// Serializer sets the serialization function to use for sending span data to
// Zipkin.
func Serializer(serializer reporter.SpanSerializer) ReporterOption {
return func(r *httpReporter) {
if serializer != nil {
r.serializer = serializer
}
}
}
// NewReporter returns a new HTTP Reporter.
// url should be the endpoint to send the spans to, e.g.
// http://localhost:9411/api/v2/spans
func NewReporter(url string, opts ...ReporterOption) reporter.Reporter {
r := httpReporter{
url: url,
logger: log.New(os.Stderr, "", log.LstdFlags),
client: &http.Client{},
batchInterval: defaultBatchInterval,
batchSize: defaultBatchSize,
maxBacklog: defaultMaxBacklog,
batch: []*model.SpanModel{},
spanC: make(chan *model.SpanModel),
sendC: make(chan struct{}, 1),
quit: make(chan struct{}, 1),
shutdown: make(chan error, 1),
batchMtx: &sync.Mutex{},
serializer: reporter.JSONSerializer{},
reqTimeout: defaultTimeout,
}
for _, opt := range opts {
opt(&r)
}
go r.loop()
go r.sendLoop()
return &r
}