This repository has been archived by the owner on Oct 3, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 21
/
ocagent.go
581 lines (505 loc) · 15.8 KB
/
ocagent.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
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
// Copyright 2020, OpenCensus 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 ocagent
import (
"context"
"errors"
"fmt"
"io"
"sync"
"time"
"unsafe"
"google.golang.org/api/support/bundler"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/metadata"
"go.opencensus.io/plugin/ocgrpc"
"go.opencensus.io/resource"
"go.opencensus.io/stats/view"
"go.opencensus.io/trace"
commonpb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/common/v1"
agentmetricspb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/metrics/v1"
agenttracepb "github.com/census-instrumentation/opencensus-proto/gen-go/agent/trace/v1"
metricspb "github.com/census-instrumentation/opencensus-proto/gen-go/metrics/v1"
resourcepb "github.com/census-instrumentation/opencensus-proto/gen-go/resource/v1"
tracepb "github.com/census-instrumentation/opencensus-proto/gen-go/trace/v1"
)
var startupMu sync.Mutex
var startTime time.Time
func init() {
startupMu.Lock()
startTime = time.Now()
startupMu.Unlock()
}
var _ trace.Exporter = (*Exporter)(nil)
var _ view.Exporter = (*Exporter)(nil)
type Exporter struct {
// mu protects the non-atomic and non-channel variables
mu sync.RWMutex
// senderMu protects the concurrent unsafe send on traceExporter client
senderMu sync.Mutex
// recvMu protects the concurrent unsafe recv on traceExporter client
recvMu sync.Mutex
started bool
stopped bool
agentAddress string
serviceName string
canDialInsecure bool
traceExporter agenttracepb.TraceService_ExportClient
metricsExporter agentmetricspb.MetricsService_ExportClient
nodeInfo *commonpb.Node
grpcClientConn *grpc.ClientConn
reconnectionPeriod time.Duration
resourceDetector resource.Detector
resource *resourcepb.Resource
compressor string
headers map[string]string
lastConnectErrPtr unsafe.Pointer
metricNamePerfix string
startOnce sync.Once
stopCh chan bool
disconnectedCh chan bool
backgroundConnectionDoneCh chan bool
traceBundler *bundler.Bundler
// viewDataBundler is the bundler to enable conversion
// from OpenCensus-Go view.Data to metricspb.Metric.
// Please do not confuse it with metricsBundler!
viewDataBundler *bundler.Bundler
// Bundler configuration options managed by viewDataBundler
viewDataDelay time.Duration
viewDataBundleCount int
clientTransportCredentials credentials.TransportCredentials
grpcDialOptions []grpc.DialOption
spanConfig SpanConfig
}
func NewExporter(opts ...ExporterOption) (*Exporter, error) {
exp, err := NewUnstartedExporter(opts...)
if err != nil {
return nil, err
}
if err := exp.Start(); err != nil {
return nil, err
}
return exp, nil
}
const spanDataBufferSize = 300
func NewUnstartedExporter(opts ...ExporterOption) (*Exporter, error) {
e := new(Exporter)
e.viewDataDelay = 2 * time.Second
e.viewDataBundleCount = 500
for _, opt := range opts {
opt.withExporter(e)
}
traceBundler := bundler.NewBundler((*trace.SpanData)(nil), func(bundle interface{}) {
e.uploadTraces(bundle.([]*trace.SpanData))
})
traceBundler.DelayThreshold = 2 * time.Second
traceBundler.BundleCountThreshold = spanDataBufferSize
e.traceBundler = traceBundler
viewDataBundler := bundler.NewBundler((*view.Data)(nil), func(bundle interface{}) {
e.uploadViewData(bundle.([]*view.Data))
})
viewDataBundler.DelayThreshold = e.viewDataDelay
viewDataBundler.BundleCountThreshold = e.viewDataBundleCount
e.viewDataBundler = viewDataBundler
e.nodeInfo = NodeWithStartTime(e.serviceName)
if e.resourceDetector != nil {
res, err := e.resourceDetector(context.Background())
if err != nil {
panic(fmt.Sprintf("Error detecting resource. err:%v\n", err))
}
if res != nil {
e.resource = resourceToResourcePb(res)
}
} else {
e.resource = resourceProtoFromEnv()
}
return e, nil
}
const (
maxInitialConfigRetries = 10
maxInitialTracesRetries = 10
)
var (
errAlreadyStarted = errors.New("already started")
errNotStarted = errors.New("not started")
errStopped = errors.New("stopped")
)
// Start dials to the agent, establishing a connection to it. It also
// initiates the Config and Trace services by sending over the initial
// messages that consist of the node identifier. Start invokes a background
// connector that will reattempt connections to the agent periodically
// if the connection dies.
func (ae *Exporter) Start() error {
var err = errAlreadyStarted
ae.startOnce.Do(func() {
ae.mu.Lock()
ae.started = true
ae.disconnectedCh = make(chan bool, 1)
ae.stopCh = make(chan bool)
ae.backgroundConnectionDoneCh = make(chan bool)
ae.mu.Unlock()
// An optimistic first connection attempt to ensure that
// applications under heavy load can immediately process
// data. See https://github.com/census-ecosystem/opencensus-go-exporter-ocagent/pull/63
if err := ae.connect(); err == nil {
ae.setStateConnected()
} else {
ae.setStateDisconnected(err)
}
go ae.indefiniteBackgroundConnection()
err = nil
})
return err
}
func (ae *Exporter) prepareAgentAddress() string {
if ae.agentAddress != "" {
return ae.agentAddress
}
return fmt.Sprintf("%s:%d", DefaultAgentHost, DefaultAgentPort)
}
func (ae *Exporter) enableConnectionStreams(cc *grpc.ClientConn) error {
ae.mu.RLock()
started := ae.started
nodeInfo := ae.nodeInfo
ae.mu.RUnlock()
if !started {
return errNotStarted
}
ae.mu.Lock()
// If the previous clientConn was non-nil, close it
if ae.grpcClientConn != nil {
_ = ae.grpcClientConn.Close()
}
ae.grpcClientConn = cc
ae.mu.Unlock()
if err := ae.createTraceServiceConnection(ae.grpcClientConn, nodeInfo); err != nil {
return err
}
return ae.createMetricsServiceConnection(ae.grpcClientConn, nodeInfo)
}
func (ae *Exporter) createTraceServiceConnection(cc *grpc.ClientConn, node *commonpb.Node) error {
// Initiate the trace service by sending over node identifier info.
traceSvcClient := agenttracepb.NewTraceServiceClient(cc)
ctx := context.Background()
if len(ae.headers) > 0 {
ctx = metadata.NewOutgoingContext(ctx, metadata.New(ae.headers))
}
traceExporter, err := traceSvcClient.Export(ctx)
if err != nil {
return fmt.Errorf("Exporter.Start:: TraceServiceClient: %v", err)
}
firstTraceMessage := &agenttracepb.ExportTraceServiceRequest{
Node: node,
Resource: ae.resource,
}
if err := traceExporter.Send(firstTraceMessage); err != nil {
return fmt.Errorf("Exporter.Start:: Failed to initiate the Config service: %v", err)
}
ae.mu.Lock()
ae.traceExporter = traceExporter
ae.mu.Unlock()
// Initiate the config service by sending over node identifier info.
configStream, err := traceSvcClient.Config(context.Background())
if err != nil {
return fmt.Errorf("Exporter.Start:: ConfigStream: %v", err)
}
firstCfgMessage := &agenttracepb.CurrentLibraryConfig{Node: node}
if err := configStream.Send(firstCfgMessage); err != nil {
return fmt.Errorf("Exporter.Start:: Failed to initiate the Config service: %v", err)
}
// In the background, handle trace configurations that are beamed down
// by the agent, but also reply to it with the applied configuration.
go ae.handleConfigStreaming(configStream)
return nil
}
func (ae *Exporter) createMetricsServiceConnection(cc *grpc.ClientConn, node *commonpb.Node) error {
metricsSvcClient := agentmetricspb.NewMetricsServiceClient(cc)
metricsExporter, err := metricsSvcClient.Export(context.Background())
if err != nil {
return fmt.Errorf("MetricsExporter: failed to start the service client: %v", err)
}
// Initiate the metrics service by sending over the first message just containing the Node and Resource.
firstMetricsMessage := &agentmetricspb.ExportMetricsServiceRequest{
Node: node,
Resource: ae.resource,
}
if err := metricsExporter.Send(firstMetricsMessage); err != nil {
return fmt.Errorf("MetricsExporter:: failed to send the first message: %v", err)
}
ae.mu.Lock()
ae.metricsExporter = metricsExporter
ae.mu.Unlock()
// With that we are good to go and can start sending metrics
return nil
}
func (ae *Exporter) dialToAgent() (*grpc.ClientConn, error) {
addr := ae.prepareAgentAddress()
var dialOpts []grpc.DialOption
if ae.clientTransportCredentials != nil {
dialOpts = append(dialOpts, grpc.WithTransportCredentials(ae.clientTransportCredentials))
} else if ae.canDialInsecure {
dialOpts = append(dialOpts, grpc.WithInsecure())
}
if ae.compressor != "" {
dialOpts = append(dialOpts, grpc.WithDefaultCallOptions(grpc.UseCompressor(ae.compressor)))
}
dialOpts = append(dialOpts, grpc.WithStatsHandler(&ocgrpc.ClientHandler{}))
if len(ae.grpcDialOptions) != 0 {
dialOpts = append(dialOpts, ae.grpcDialOptions...)
}
ctx := context.Background()
if len(ae.headers) > 0 {
ctx = metadata.NewOutgoingContext(ctx, metadata.New(ae.headers))
}
return grpc.DialContext(ctx, addr, dialOpts...)
}
func (ae *Exporter) handleConfigStreaming(configStream agenttracepb.TraceService_ConfigClient) error {
// Note: We haven't yet implemented configuration sending so we
// should NOT be changing connection states within this function for now.
for {
recv, err := configStream.Recv()
if err != nil {
// TODO: Check if this is a transient error or exponential backoff-able.
return err
}
cfg := recv.Config
if cfg == nil {
continue
}
// Otherwise now apply the trace configuration sent down from the agent
if psamp := cfg.GetProbabilitySampler(); psamp != nil {
trace.ApplyConfig(trace.Config{DefaultSampler: trace.ProbabilitySampler(psamp.SamplingProbability)})
} else if csamp := cfg.GetConstantSampler(); csamp != nil {
alwaysSample := csamp.Decision == tracepb.ConstantSampler_ALWAYS_ON
if alwaysSample {
trace.ApplyConfig(trace.Config{DefaultSampler: trace.AlwaysSample()})
} else {
trace.ApplyConfig(trace.Config{DefaultSampler: trace.NeverSample()})
}
} else { // TODO: Add the rate limiting sampler here
}
// Then finally send back to upstream the newly applied configuration
err = configStream.Send(&agenttracepb.CurrentLibraryConfig{Config: &tracepb.TraceConfig{Sampler: cfg.Sampler}})
if err != nil {
return err
}
}
}
// Stop shuts down all the connections and resources
// related to the exporter.
func (ae *Exporter) Stop() error {
ae.mu.RLock()
cc := ae.grpcClientConn
started := ae.started
stopped := ae.stopped
ae.mu.RUnlock()
if !started {
return errNotStarted
}
if stopped {
// TODO: tell the user that we've already stopped, so perhaps a sentinel error?
return nil
}
ae.Flush()
// Now close the underlying gRPC connection.
var err error
if cc != nil {
err = cc.Close()
}
// At this point we can change the state variables: started and stopped
ae.mu.Lock()
ae.started = false
ae.stopped = true
ae.mu.Unlock()
close(ae.stopCh)
// Ensure that the backgroundConnector returns
<-ae.backgroundConnectionDoneCh
return err
}
func (ae *Exporter) ExportSpan(sd *trace.SpanData) {
if sd == nil {
return
}
_ = ae.traceBundler.Add(sd, 1)
}
func (ae *Exporter) ExportTraceServiceRequest(batch *agenttracepb.ExportTraceServiceRequest) error {
if batch == nil || len(batch.Spans) == 0 {
return nil
}
select {
case <-ae.stopCh:
return errStopped
default:
if lastConnectErr := ae.lastConnectError(); lastConnectErr != nil {
return fmt.Errorf("ExportTraceServiceRequest: no active connection, last connection error: %v", lastConnectErr)
}
ae.senderMu.Lock()
err := ae.traceExporter.Send(batch)
ae.senderMu.Unlock()
if err != nil {
if err == io.EOF {
ae.recvMu.Lock()
// Perform a .Recv to try to find out why the RPC actually ended.
// See:
// * https://github.com/grpc/grpc-go/blob/d389f9fac68eea0dcc49957d0b4cca5b3a0a7171/stream.go#L98-L100
// * https://groups.google.com/forum/#!msg/grpc-io/XcN4hA9HonI/F_UDiejTAwAJ
for {
_, err = ae.traceExporter.Recv()
if err != nil {
break
}
}
ae.recvMu.Unlock()
}
ae.setStateDisconnected(err)
if err != io.EOF {
return err
}
}
return nil
}
}
func (ae *Exporter) ExportView(vd *view.Data) {
if vd == nil {
return
}
_ = ae.viewDataBundler.Add(vd, 1)
}
// ExportMetricsServiceRequest sends proto metrics with the metrics service client.
func (ae *Exporter) ExportMetricsServiceRequest(batch *agentmetricspb.ExportMetricsServiceRequest) error {
if batch == nil || len(batch.Metrics) == 0 {
return nil
}
select {
case <-ae.stopCh:
return errStopped
default:
if lastConnectErr := ae.lastConnectError(); lastConnectErr != nil {
return fmt.Errorf("ExportMetricsServiceRequest: no active connection, last connection error: %v", lastConnectErr)
}
ae.senderMu.Lock()
err := ae.metricsExporter.Send(batch)
ae.senderMu.Unlock()
if err != nil {
if err == io.EOF {
ae.recvMu.Lock()
// Perform a .Recv to try to find out why the RPC actually ended.
// See:
// * https://github.com/grpc/grpc-go/blob/d389f9fac68eea0dcc49957d0b4cca5b3a0a7171/stream.go#L98-L100
// * https://groups.google.com/forum/#!msg/grpc-io/XcN4hA9HonI/F_UDiejTAwAJ
for {
_, err = ae.metricsExporter.Recv()
if err != nil {
break
}
}
ae.recvMu.Unlock()
}
ae.setStateDisconnected(err)
if err != io.EOF {
return err
}
}
return nil
}
}
func ocSpanDataToPbSpans(sdl []*trace.SpanData, spanConfig SpanConfig) []*tracepb.Span {
if len(sdl) == 0 {
return nil
}
protoSpans := make([]*tracepb.Span, 0, len(sdl))
for _, sd := range sdl {
if sd != nil {
protoSpans = append(protoSpans, ocSpanToProtoSpan(sd, spanConfig))
}
}
return protoSpans
}
func (ae *Exporter) uploadTraces(sdl []*trace.SpanData) {
select {
case <-ae.stopCh:
return
default:
if !ae.connected() {
return
}
protoSpans := ocSpanDataToPbSpans(sdl, ae.spanConfig)
if len(protoSpans) == 0 {
return
}
ae.senderMu.Lock()
err := ae.traceExporter.Send(&agenttracepb.ExportTraceServiceRequest{
Spans: protoSpans,
Resource: ae.resource,
})
ae.senderMu.Unlock()
if err != nil {
ae.setStateDisconnected(err)
}
}
}
func ocViewDataToPbMetrics(vdl []*view.Data, metricNamePrefix string) []*metricspb.Metric {
if len(vdl) == 0 {
return nil
}
metrics := make([]*metricspb.Metric, 0, len(vdl))
for _, vd := range vdl {
if vd != nil {
vmetric, err := viewDataToMetric(vd, metricNamePrefix)
// TODO: (@odeke-em) somehow report this error, if it is non-nil.
if err == nil && vmetric != nil {
metrics = append(metrics, vmetric)
}
}
}
return metrics
}
func (ae *Exporter) uploadViewData(vdl []*view.Data) {
protoMetrics := ocViewDataToPbMetrics(vdl, ae.metricNamePerfix)
if len(protoMetrics) == 0 {
return
}
req := &agentmetricspb.ExportMetricsServiceRequest{
Metrics: protoMetrics,
Resource: ae.resource,
// TODO:(@odeke-em)
// a) Figure out how to derive a Node from the environment
// or better letting users of the exporter configure it.
}
ae.ExportMetricsServiceRequest(req)
}
func (ae *Exporter) Flush() {
ae.traceBundler.Flush()
ae.viewDataBundler.Flush()
}
func resourceProtoFromEnv() *resourcepb.Resource {
rs, _ := resource.FromEnv(context.Background())
if rs == nil {
return nil
}
return resourceToResourcePb(rs)
}
func resourceToResourcePb(rs *resource.Resource) *resourcepb.Resource {
rprs := &resourcepb.Resource{
Type: rs.Type,
}
if rs.Labels != nil {
rprs.Labels = make(map[string]string)
for k, v := range rs.Labels {
rprs.Labels[k] = v
}
}
return rprs
}