-
Notifications
You must be signed in to change notification settings - Fork 4.4k
/
transport.go
435 lines (399 loc) · 13.6 KB
/
transport.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
/*
*
* Copyright 2020 gRPC 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 controller
import (
"context"
"fmt"
"time"
"github.com/golang/protobuf/proto"
"google.golang.org/grpc"
controllerversion "google.golang.org/grpc/xds/internal/xdsclient/controller/version"
xdsresourceversion "google.golang.org/grpc/xds/internal/xdsclient/controller/version"
"google.golang.org/grpc/xds/internal/xdsclient/load"
"google.golang.org/grpc/xds/internal/xdsclient/xdsresource"
)
// AddWatch adds a watch for an xDS resource given its type and name.
func (t *Controller) AddWatch(rType xdsresource.ResourceType, resourceName string) {
t.sendCh.Put(&watchAction{
rType: rType,
remove: false,
resource: resourceName,
})
}
// RemoveWatch cancels an already registered watch for an xDS resource
// given its type and name.
func (t *Controller) RemoveWatch(rType xdsresource.ResourceType, resourceName string) {
t.sendCh.Put(&watchAction{
rType: rType,
remove: true,
resource: resourceName,
})
}
// run starts an ADS stream (and backs off exponentially, if the previous
// stream failed without receiving a single reply) and runs the sender and
// receiver routines to send and receive data from the stream respectively.
func (t *Controller) run(ctx context.Context) {
go t.send(ctx)
// TODO: start a goroutine monitoring ClientConn's connectivity state, and
// report error (and log) when stats is transient failure.
retries := 0
lastStreamStartTime := time.Time{}
for ctx.Err() == nil {
dur := time.Until(lastStreamStartTime.Add(t.backoff(retries)))
if dur > 0 {
timer := time.NewTimer(dur)
select {
case <-timer.C:
case <-ctx.Done():
timer.Stop()
return
}
}
retries++
lastStreamStartTime = time.Now()
stream, err := t.vClient.NewStream(ctx, t.cc)
if err != nil {
t.updateHandler.NewConnectionError(err)
t.logger.Warningf("xds: ADS stream creation failed: %v", err)
continue
}
t.logger.Infof("ADS stream created")
select {
case <-t.streamCh:
default:
}
t.streamCh <- stream
if t.recv(stream) {
retries = 0
}
}
}
// send is a separate goroutine for sending watch requests on the xds stream.
//
// It watches the stream channel for new streams, and the request channel for
// new requests to send on the stream.
//
// For each new request (watchAction), it's
// - processed and added to the watch map
// so, resend will pick them up when there are new streams
// - sent on the current stream if there's one
// the current stream is cleared when any send on it fails
//
// For each new stream, all the existing requests will be resent.
//
// Note that this goroutine doesn't do anything to the old stream when there's a
// new one. In fact, there should be only one stream in progress, and new one
// should only be created when the old one fails (recv returns an error).
func (t *Controller) send(ctx context.Context) {
var stream grpc.ClientStream
for {
select {
case <-ctx.Done():
return
case stream = <-t.streamCh:
if !t.sendExisting(stream) {
// send failed, clear the current stream.
stream = nil
}
case u := <-t.sendCh.Get():
t.sendCh.Load()
var (
target []string
rType xdsresource.ResourceType
version, nonce, errMsg string
send bool
)
switch update := u.(type) {
case *watchAction:
target, rType, version, nonce = t.processWatchInfo(update)
case *ackAction:
target, rType, version, nonce, send = t.processAckInfo(update, stream)
if !send {
continue
}
errMsg = update.errMsg
}
if stream == nil {
// There's no stream yet. Skip the request. This request
// will be resent to the new streams. If no stream is
// created, the watcher will timeout (same as server not
// sending response back).
continue
}
if err := t.vClient.SendRequest(stream, target, rType, version, nonce, errMsg); err != nil {
t.logger.Warningf("ADS request for {target: %q, type: %v, version: %q, nonce: %q} failed: %v", target, rType, version, nonce, err)
// send failed, clear the current stream.
stream = nil
}
}
}
}
// sendExisting sends out xDS requests for registered watchers when recovering
// from a broken stream.
//
// We call stream.Send() here with the lock being held. It should be OK to do
// that here because the stream has just started and Send() usually returns
// quickly (once it pushes the message onto the transport layer) and is only
// ever blocked if we don't have enough flow control quota.
func (t *Controller) sendExisting(stream grpc.ClientStream) bool {
t.mu.Lock()
defer t.mu.Unlock()
// Reset only the nonce when the stream restarts.
//
// xDS spec says the following. See section:
// https://www.envoyproxy.io/docs/envoy/latest/api-docs/xds_protocol#ack-nack-and-resource-type-instance-version
//
// Note that the version for a resource type is not a property of an
// individual xDS stream but rather a property of the resources themselves. If
// the stream becomes broken and the client creates a new stream, the client’s
// initial request on the new stream should indicate the most recent version
// seen by the client on the previous stream
t.nonceMap = make(map[xdsresource.ResourceType]string)
for rType, s := range t.watchMap {
if err := t.vClient.SendRequest(stream, mapToSlice(s), rType, t.versionMap[rType], "", ""); err != nil {
t.logger.Warningf("ADS request failed: %v", err)
return false
}
}
return true
}
// recv receives xDS responses on the provided ADS stream and branches out to
// message specific handlers.
func (t *Controller) recv(stream grpc.ClientStream) bool {
msgReceived := false
for {
resp, err := t.vClient.RecvResponse(stream)
if err != nil {
t.updateHandler.NewConnectionError(err)
t.logger.Warningf("ADS stream is closed with error: %v", err)
return msgReceived
}
msgReceived = true
rType, version, nonce, err := t.handleResponse(resp)
if e, ok := err.(xdsresourceversion.ErrResourceTypeUnsupported); ok {
t.logger.Warningf("%s", e.ErrStr)
continue
}
if err != nil {
t.sendCh.Put(&ackAction{
rType: rType,
version: "",
nonce: nonce,
errMsg: err.Error(),
stream: stream,
})
t.logger.Warningf("Sending NACK for response type: %v, version: %v, nonce: %v, reason: %v", rType, version, nonce, err)
continue
}
t.sendCh.Put(&ackAction{
rType: rType,
version: version,
nonce: nonce,
stream: stream,
})
t.logger.Infof("Sending ACK for response type: %v, version: %v, nonce: %v", rType, version, nonce)
}
}
func (t *Controller) handleResponse(resp proto.Message) (xdsresource.ResourceType, string, string, error) {
rType, resource, version, nonce, err := t.vClient.ParseResponse(resp)
if err != nil {
return rType, version, nonce, err
}
opts := &xdsresource.UnmarshalOptions{
Version: version,
Resources: resource,
Logger: t.logger,
UpdateValidator: t.updateValidator,
}
var md xdsresource.UpdateMetadata
switch rType {
case xdsresource.ListenerResource:
var update map[string]xdsresource.ListenerUpdateErrTuple
update, md, err = xdsresource.UnmarshalListener(opts)
t.updateHandler.NewListeners(update, md)
case xdsresource.RouteConfigResource:
var update map[string]xdsresource.RouteConfigUpdateErrTuple
update, md, err = xdsresource.UnmarshalRouteConfig(opts)
t.updateHandler.NewRouteConfigs(update, md)
case xdsresource.ClusterResource:
var update map[string]xdsresource.ClusterUpdateErrTuple
update, md, err = xdsresource.UnmarshalCluster(opts)
t.updateHandler.NewClusters(update, md)
case xdsresource.EndpointsResource:
var update map[string]xdsresource.EndpointsUpdateErrTuple
update, md, err = xdsresource.UnmarshalEndpoints(opts)
t.updateHandler.NewEndpoints(update, md)
default:
return rType, "", "", xdsresourceversion.ErrResourceTypeUnsupported{
ErrStr: fmt.Sprintf("Resource type %v unknown in response from server", rType),
}
}
return rType, version, nonce, err
}
func mapToSlice(m map[string]bool) []string {
ret := make([]string, 0, len(m))
for i := range m {
ret = append(ret, i)
}
return ret
}
type watchAction struct {
rType xdsresource.ResourceType
remove bool // Whether this is to remove watch for the resource.
resource string
}
// processWatchInfo pulls the fields needed by the request from a watchAction.
//
// It also updates the watch map.
func (t *Controller) processWatchInfo(w *watchAction) (target []string, rType xdsresource.ResourceType, ver, nonce string) {
t.mu.Lock()
defer t.mu.Unlock()
var current map[string]bool
current, ok := t.watchMap[w.rType]
if !ok {
current = make(map[string]bool)
t.watchMap[w.rType] = current
}
if w.remove {
delete(current, w.resource)
if len(current) == 0 {
delete(t.watchMap, w.rType)
}
} else {
current[w.resource] = true
}
rType = w.rType
target = mapToSlice(current)
// We don't reset version or nonce when a new watch is started. The version
// and nonce from previous response are carried by the request. Only the nonce
// is reset when the stream is recreated.
ver = t.versionMap[rType]
nonce = t.nonceMap[rType]
return target, rType, ver, nonce
}
type ackAction struct {
rType xdsresource.ResourceType
version string // NACK if version is an empty string.
nonce string
errMsg string // Empty unless it's a NACK.
// ACK/NACK are tagged with the stream it's for. When the stream is down,
// all the ACK/NACK for this stream will be dropped, and the version/nonce
// won't be updated.
stream grpc.ClientStream
}
// processAckInfo pulls the fields needed by the ack request from a ackAction.
//
// If no active watch is found for this ack, it returns false for send.
func (t *Controller) processAckInfo(ack *ackAction, stream grpc.ClientStream) (target []string, rType xdsresource.ResourceType, version, nonce string, send bool) {
if ack.stream != stream {
// If ACK's stream isn't the current sending stream, this means the ACK
// was pushed to queue before the old stream broke, and a new stream has
// been started since. Return immediately here so we don't update the
// nonce for the new stream.
return nil, xdsresource.UnknownResource, "", "", false
}
rType = ack.rType
t.mu.Lock()
defer t.mu.Unlock()
// Update the nonce no matter if we are going to send the ACK request on
// wire. We may not send the request if the watch is canceled. But the nonce
// needs to be updated so the next request will have the right nonce.
nonce = ack.nonce
t.nonceMap[rType] = nonce
s, ok := t.watchMap[rType]
if !ok || len(s) == 0 {
// We don't send the request ack if there's no active watch (this can be
// either the server sends responses before any request, or the watch is
// canceled while the ackAction is in queue), because there's no resource
// name. And if we send a request with empty resource name list, the
// server may treat it as a wild card and send us everything.
return nil, xdsresource.UnknownResource, "", "", false
}
send = true
target = mapToSlice(s)
version = ack.version
if version == "" {
// This is a nack, get the previous acked version.
version = t.versionMap[rType]
// version will still be an empty string if rType isn't
// found in versionMap, this can happen if there wasn't any ack
// before.
} else {
t.versionMap[rType] = version
}
return target, rType, version, nonce, send
}
// reportLoad starts an LRS stream to report load data to the management server.
// It blocks until the context is cancelled.
func (t *Controller) reportLoad(ctx context.Context, cc *grpc.ClientConn, opts controllerversion.LoadReportingOptions) {
retries := 0
lastStreamStartTime := time.Time{}
for ctx.Err() == nil {
dur := time.Until(lastStreamStartTime.Add(t.backoff(retries)))
if dur > 0 {
timer := time.NewTimer(dur)
select {
case <-timer.C:
case <-ctx.Done():
timer.Stop()
return
}
}
retries++
lastStreamStartTime = time.Now()
func() {
// streamCtx is created and canceled in case we terminate the stream
// early for any reason, to avoid gRPC-Go leaking the RPC's monitoring
// goroutine.
streamCtx, cancel := context.WithCancel(ctx)
defer cancel()
stream, err := t.vClient.NewLoadStatsStream(streamCtx, cc)
if err != nil {
t.logger.Warningf("lrs: failed to create stream: %v", err)
return
}
t.logger.Infof("lrs: created LRS stream")
if err := t.vClient.SendFirstLoadStatsRequest(stream); err != nil {
t.logger.Warningf("lrs: failed to send first request: %v", err)
return
}
clusters, interval, err := t.vClient.HandleLoadStatsResponse(stream)
if err != nil {
t.logger.Warningf("lrs: error from stream: %v", err)
return
}
retries = 0
t.sendLoads(streamCtx, stream, opts.LoadStore, clusters, interval)
}()
}
}
func (t *Controller) sendLoads(ctx context.Context, stream grpc.ClientStream, store *load.Store, clusterNames []string, interval time.Duration) {
tick := time.NewTicker(interval)
defer tick.Stop()
for {
select {
case <-tick.C:
case <-ctx.Done():
return
}
if err := t.vClient.SendLoadStatsRequest(stream, store.Stats(clusterNames)); err != nil {
t.logger.Warningf("lrs: error from stream: %v", err)
return
}
}
}