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
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
|
/*
*
* Copyright 2016 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.
*
*/
#include <algorithm>
#include <memory>
#include <mutex>
#include <random>
#include <thread>
#include <grpc/grpc.h>
#include <grpc/support/alloc.h>
#include <grpc/support/atm.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/time.h>
#include <grpcpp/channel.h>
#include <grpcpp/client_context.h>
#include <grpcpp/create_channel.h>
#include <grpcpp/server.h>
#include <grpcpp/server_builder.h>
#include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
#include "src/core/ext/filters/client_channel/subchannel_index.h"
#include "src/core/lib/backoff/backoff.h"
#include "src/core/lib/gpr/env.h"
#include "src/core/lib/gprpp/debug_location.h"
#include "src/core/lib/gprpp/ref_counted_ptr.h"
#include "src/core/lib/iomgr/tcp_client.h"
#include "src/proto/grpc/testing/echo.grpc.pb.h"
#include "test/core/util/port.h"
#include "test/core/util/test_config.h"
#include "test/cpp/end2end/test_service_impl.h"
#include <gtest/gtest.h>
using grpc::testing::EchoRequest;
using grpc::testing::EchoResponse;
using std::chrono::system_clock;
// defined in tcp_client.cc
extern grpc_tcp_client_vtable* grpc_tcp_client_impl;
static grpc_tcp_client_vtable* default_client_impl;
namespace grpc {
namespace testing {
namespace {
gpr_atm g_connection_delay_ms;
void tcp_client_connect_with_delay(grpc_closure* closure, grpc_endpoint** ep,
grpc_pollset_set* interested_parties,
const grpc_channel_args* channel_args,
const grpc_resolved_address* addr,
grpc_millis deadline) {
const int delay_ms = gpr_atm_acq_load(&g_connection_delay_ms);
if (delay_ms > 0) {
gpr_sleep_until(grpc_timeout_milliseconds_to_deadline(delay_ms));
}
default_client_impl->connect(closure, ep, interested_parties, channel_args,
addr, deadline + delay_ms);
}
grpc_tcp_client_vtable delayed_connect = {tcp_client_connect_with_delay};
// Subclass of TestServiceImpl that increments a request counter for
// every call to the Echo RPC.
class MyTestServiceImpl : public TestServiceImpl {
public:
MyTestServiceImpl() : request_count_(0) {}
Status Echo(ServerContext* context, const EchoRequest* request,
EchoResponse* response) override {
{
std::unique_lock<std::mutex> lock(mu_);
++request_count_;
}
return TestServiceImpl::Echo(context, request, response);
}
int request_count() {
std::unique_lock<std::mutex> lock(mu_);
return request_count_;
}
void ResetCounters() {
std::unique_lock<std::mutex> lock(mu_);
request_count_ = 0;
}
private:
std::mutex mu_;
int request_count_;
};
class ClientLbEnd2endTest : public ::testing::Test {
protected:
ClientLbEnd2endTest()
: server_host_("localhost"), kRequestMessage_("Live long and prosper.") {
// Make the backup poller poll very frequently in order to pick up
// updates from all the subchannels's FDs.
gpr_setenv("GRPC_CLIENT_CHANNEL_BACKUP_POLL_INTERVAL_MS", "1");
}
void SetUp() override {
response_generator_ =
grpc_core::MakeRefCounted<grpc_core::FakeResolverResponseGenerator>();
}
void TearDown() override {
for (size_t i = 0; i < servers_.size(); ++i) {
servers_[i]->Shutdown();
}
}
void CreateServers(size_t num_servers,
std::vector<int> ports = std::vector<int>()) {
servers_.clear();
for (size_t i = 0; i < num_servers; ++i) {
int port = 0;
if (ports.size() == num_servers) port = ports[i];
servers_.emplace_back(new ServerData(port));
}
}
void StartServer(size_t index) {
servers_[index]->Start(server_host_);
}
void StartServers(size_t num_servers,
std::vector<int> ports = std::vector<int>()) {
CreateServers(num_servers, ports);
for (size_t i = 0; i < num_servers; ++i) {
StartServer(i);
}
}
grpc_channel_args* BuildFakeResults(const std::vector<int>& ports) {
grpc_lb_addresses* addresses =
grpc_lb_addresses_create(ports.size(), nullptr);
for (size_t i = 0; i < ports.size(); ++i) {
char* lb_uri_str;
gpr_asprintf(&lb_uri_str, "ipv4:127.0.0.1:%d", ports[i]);
grpc_uri* lb_uri = grpc_uri_parse(lb_uri_str, true);
GPR_ASSERT(lb_uri != nullptr);
grpc_lb_addresses_set_address_from_uri(addresses, i, lb_uri,
false /* is balancer */,
"" /* balancer name */, nullptr);
grpc_uri_destroy(lb_uri);
gpr_free(lb_uri_str);
}
const grpc_arg fake_addresses =
grpc_lb_addresses_create_channel_arg(addresses);
grpc_channel_args* fake_results =
grpc_channel_args_copy_and_add(nullptr, &fake_addresses, 1);
grpc_lb_addresses_destroy(addresses);
return fake_results;
}
void SetNextResolution(const std::vector<int>& ports) {
grpc_core::ExecCtx exec_ctx;
grpc_channel_args* fake_results = BuildFakeResults(ports);
response_generator_->SetResponse(fake_results);
grpc_channel_args_destroy(fake_results);
}
void SetNextResolutionUponError(const std::vector<int>& ports) {
grpc_core::ExecCtx exec_ctx;
grpc_channel_args* fake_results = BuildFakeResults(ports);
response_generator_->SetReresolutionResponse(fake_results);
grpc_channel_args_destroy(fake_results);
}
std::vector<int> GetServersPorts() {
std::vector<int> ports;
for (const auto& server : servers_) ports.push_back(server->port_);
return ports;
}
std::unique_ptr<grpc::testing::EchoTestService::Stub> BuildStub(
const std::shared_ptr<Channel>& channel) {
return grpc::testing::EchoTestService::NewStub(channel);
}
std::shared_ptr<Channel> BuildChannel(
const grpc::string& lb_policy_name,
ChannelArguments args = ChannelArguments()) {
if (lb_policy_name.size() > 0) {
args.SetLoadBalancingPolicyName(lb_policy_name);
} // else, default to pick first
args.SetPointer(GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR,
response_generator_.get());
return CreateCustomChannel("fake:///", InsecureChannelCredentials(), args);
}
bool SendRpc(
const std::unique_ptr<grpc::testing::EchoTestService::Stub>& stub,
EchoResponse* response = nullptr, int timeout_ms = 1000,
Status* result = nullptr) {
const bool local_response = (response == nullptr);
if (local_response) response = new EchoResponse;
EchoRequest request;
request.set_message(kRequestMessage_);
ClientContext context;
context.set_deadline(grpc_timeout_milliseconds_to_deadline(timeout_ms));
Status status = stub->Echo(&context, request, response);
if (result != nullptr) *result = status;
if (local_response) delete response;
return status.ok();
}
void CheckRpcSendOk(
const std::unique_ptr<grpc::testing::EchoTestService::Stub>& stub,
const grpc_core::DebugLocation& location) {
EchoResponse response;
Status status;
const bool success = SendRpc(stub, &response, 2000, &status);
ASSERT_TRUE(success) << "From " << location.file() << ":" << location.line()
<< "\n"
<< "Error: " << status.error_message() << " "
<< status.error_details();
ASSERT_EQ(response.message(), kRequestMessage_)
<< "From " << location.file() << ":" << location.line();
if (!success) abort();
}
void CheckRpcSendFailure(
const std::unique_ptr<grpc::testing::EchoTestService::Stub>& stub) {
const bool success = SendRpc(stub);
EXPECT_FALSE(success);
}
struct ServerData {
int port_;
std::unique_ptr<Server> server_;
MyTestServiceImpl service_;
std::unique_ptr<std::thread> thread_;
bool server_ready_ = false;
explicit ServerData(int port = 0) {
port_ = port > 0 ? port : grpc_pick_unused_port_or_die();
}
void Start(const grpc::string& server_host) {
gpr_log(GPR_INFO, "starting server on port %d", port_);
std::mutex mu;
std::unique_lock<std::mutex> lock(mu);
std::condition_variable cond;
thread_.reset(new std::thread(
std::bind(&ServerData::Serve, this, server_host, &mu, &cond)));
cond.wait(lock, [this] { return server_ready_; });
server_ready_ = false;
gpr_log(GPR_INFO, "server startup complete");
}
void Serve(const grpc::string& server_host, std::mutex* mu,
std::condition_variable* cond) {
std::ostringstream server_address;
server_address << server_host << ":" << port_;
ServerBuilder builder;
builder.AddListeningPort(server_address.str(),
InsecureServerCredentials());
builder.RegisterService(&service_);
server_ = builder.BuildAndStart();
std::lock_guard<std::mutex> lock(*mu);
server_ready_ = true;
cond->notify_one();
}
void Shutdown(bool join = true) {
server_->Shutdown(grpc_timeout_milliseconds_to_deadline(0));
if (join) thread_->join();
}
};
void ResetCounters() {
for (const auto& server : servers_) server->service_.ResetCounters();
}
void WaitForServer(
const std::unique_ptr<grpc::testing::EchoTestService::Stub>& stub,
size_t server_idx, const grpc_core::DebugLocation& location,
bool ignore_failure = false) {
do {
if (ignore_failure) {
SendRpc(stub);
} else {
CheckRpcSendOk(stub, location);
}
} while (servers_[server_idx]->service_.request_count() == 0);
ResetCounters();
}
bool WaitForChannelNotReady(Channel* channel, int timeout_seconds = 5) {
const gpr_timespec deadline =
grpc_timeout_seconds_to_deadline(timeout_seconds);
grpc_connectivity_state state;
while ((state = channel->GetState(false /* try_to_connect */)) ==
GRPC_CHANNEL_READY) {
if (!channel->WaitForStateChange(state, deadline)) return false;
}
return true;
}
bool SeenAllServers() {
for (const auto& server : servers_) {
if (server->service_.request_count() == 0) return false;
}
return true;
}
// Updates \a connection_order by appending to it the index of the newly
// connected server. Must be called after every single RPC.
void UpdateConnectionOrder(
const std::vector<std::unique_ptr<ServerData>>& servers,
std::vector<int>* connection_order) {
for (size_t i = 0; i < servers.size(); ++i) {
if (servers[i]->service_.request_count() == 1) {
// Was the server index known? If not, update connection_order.
const auto it =
std::find(connection_order->begin(), connection_order->end(), i);
if (it == connection_order->end()) {
connection_order->push_back(i);
return;
}
}
}
}
const grpc::string server_host_;
std::unique_ptr<grpc::testing::EchoTestService::Stub> stub_;
std::vector<std::unique_ptr<ServerData>> servers_;
grpc_core::RefCountedPtr<grpc_core::FakeResolverResponseGenerator>
response_generator_;
const grpc::string kRequestMessage_;
};
TEST_F(ClientLbEnd2endTest, PickFirst) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel(""); // test that pick first is the default.
auto stub = BuildStub(channel);
std::vector<int> ports;
for (size_t i = 0; i < servers_.size(); ++i) {
ports.emplace_back(servers_[i]->port_);
}
SetNextResolution(ports);
for (size_t i = 0; i < servers_.size(); ++i) {
CheckRpcSendOk(stub, DEBUG_LOCATION);
}
// All requests should have gone to a single server.
bool found = false;
for (size_t i = 0; i < servers_.size(); ++i) {
const int request_count = servers_[i]->service_.request_count();
if (request_count == kNumServers) {
found = true;
} else {
EXPECT_EQ(0, request_count);
}
}
EXPECT_TRUE(found);
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, PickFirstProcessPending) {
StartServers(1); // Single server
auto channel = BuildChannel(""); // test that pick first is the default.
auto stub = BuildStub(channel);
SetNextResolution({servers_[0]->port_});
WaitForServer(stub, 0, DEBUG_LOCATION);
// Create a new channel and its corresponding PF LB policy, which will pick
// the subchannels in READY state from the previous RPC against the same
// target (even if it happened over a different channel, because subchannels
// are globally reused). Progress should happen without any transition from
// this READY state.
auto second_channel = BuildChannel("");
auto second_stub = BuildStub(second_channel);
SetNextResolution({servers_[0]->port_});
CheckRpcSendOk(second_stub, DEBUG_LOCATION);
}
TEST_F(ClientLbEnd2endTest, PickFirstBackOffInitialReconnect) {
ChannelArguments args;
constexpr int kInitialBackOffMs = 100;
args.SetInt(GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS, kInitialBackOffMs);
const std::vector<int> ports = {grpc_pick_unused_port_or_die()};
const gpr_timespec t0 = gpr_now(GPR_CLOCK_MONOTONIC);
auto channel = BuildChannel("pick_first", args);
auto stub = BuildStub(channel);
SetNextResolution(ports);
// The channel won't become connected (there's no server).
ASSERT_FALSE(channel->WaitForConnected(
grpc_timeout_milliseconds_to_deadline(kInitialBackOffMs * 2)));
// Bring up a server on the chosen port.
StartServers(1, ports);
// Now it will.
ASSERT_TRUE(channel->WaitForConnected(
grpc_timeout_milliseconds_to_deadline(kInitialBackOffMs * 2)));
const gpr_timespec t1 = gpr_now(GPR_CLOCK_MONOTONIC);
const grpc_millis waited_ms = gpr_time_to_millis(gpr_time_sub(t1, t0));
gpr_log(GPR_DEBUG, "Waited %" PRId64 " milliseconds", waited_ms);
// We should have waited at least kInitialBackOffMs. We substract one to
// account for test and precision accuracy drift.
EXPECT_GE(waited_ms, kInitialBackOffMs - 1);
// But not much more.
EXPECT_GT(
gpr_time_cmp(
grpc_timeout_milliseconds_to_deadline(kInitialBackOffMs * 1.10), t1),
0);
}
TEST_F(ClientLbEnd2endTest, PickFirstBackOffMinReconnect) {
ChannelArguments args;
constexpr int kMinReconnectBackOffMs = 1000;
args.SetInt(GRPC_ARG_MIN_RECONNECT_BACKOFF_MS, kMinReconnectBackOffMs);
const std::vector<int> ports = {grpc_pick_unused_port_or_die()};
auto channel = BuildChannel("pick_first", args);
auto stub = BuildStub(channel);
SetNextResolution(ports);
// Make connection delay a 10% longer than it's willing to in order to make
// sure we are hitting the codepath that waits for the min reconnect backoff.
gpr_atm_rel_store(&g_connection_delay_ms, kMinReconnectBackOffMs * 1.10);
default_client_impl = grpc_tcp_client_impl;
grpc_set_tcp_client_impl(&delayed_connect);
const gpr_timespec t0 = gpr_now(GPR_CLOCK_MONOTONIC);
channel->WaitForConnected(
grpc_timeout_milliseconds_to_deadline(kMinReconnectBackOffMs * 2));
const gpr_timespec t1 = gpr_now(GPR_CLOCK_MONOTONIC);
const grpc_millis waited_ms = gpr_time_to_millis(gpr_time_sub(t1, t0));
gpr_log(GPR_DEBUG, "Waited %" PRId64 " ms", waited_ms);
// We should have waited at least kMinReconnectBackOffMs. We substract one to
// account for test and precision accuracy drift.
EXPECT_GE(waited_ms, kMinReconnectBackOffMs - 1);
gpr_atm_rel_store(&g_connection_delay_ms, 0);
}
TEST_F(ClientLbEnd2endTest, PickFirstResetConnectionBackoff) {
ChannelArguments args;
constexpr int kInitialBackOffMs = 1000;
args.SetInt(GRPC_ARG_INITIAL_RECONNECT_BACKOFF_MS, kInitialBackOffMs);
const std::vector<int> ports = {grpc_pick_unused_port_or_die()};
auto channel = BuildChannel("pick_first", args);
auto stub = BuildStub(channel);
SetNextResolution(ports);
// The channel won't become connected (there's no server).
EXPECT_FALSE(
channel->WaitForConnected(grpc_timeout_milliseconds_to_deadline(10)));
// Bring up a server on the chosen port.
StartServers(1, ports);
const gpr_timespec t0 = gpr_now(GPR_CLOCK_MONOTONIC);
// Wait for connect, but not long enough. This proves that we're
// being throttled by initial backoff.
EXPECT_FALSE(
channel->WaitForConnected(grpc_timeout_milliseconds_to_deadline(10)));
// Reset connection backoff.
experimental::ChannelResetConnectionBackoff(channel.get());
// Wait for connect. Should happen ~immediately.
EXPECT_TRUE(
channel->WaitForConnected(grpc_timeout_milliseconds_to_deadline(10)));
const gpr_timespec t1 = gpr_now(GPR_CLOCK_MONOTONIC);
const grpc_millis waited_ms = gpr_time_to_millis(gpr_time_sub(t1, t0));
gpr_log(GPR_DEBUG, "Waited %" PRId64 " milliseconds", waited_ms);
// We should have waited less than kInitialBackOffMs.
EXPECT_LT(waited_ms, kInitialBackOffMs);
}
TEST_F(ClientLbEnd2endTest, PickFirstUpdates) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("pick_first");
auto stub = BuildStub(channel);
std::vector<int> ports;
// Perform one RPC against the first server.
ports.emplace_back(servers_[0]->port_);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** SET [0] *******");
CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(servers_[0]->service_.request_count(), 1);
// An empty update will result in the channel going into TRANSIENT_FAILURE.
ports.clear();
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** SET none *******");
grpc_connectivity_state channel_state;
do {
channel_state = channel->GetState(true /* try to connect */);
} while (channel_state == GRPC_CHANNEL_READY);
GPR_ASSERT(channel_state != GRPC_CHANNEL_READY);
servers_[0]->service_.ResetCounters();
// Next update introduces servers_[1], making the channel recover.
ports.clear();
ports.emplace_back(servers_[1]->port_);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** SET [1] *******");
WaitForServer(stub, 1, DEBUG_LOCATION);
EXPECT_EQ(servers_[0]->service_.request_count(), 0);
// And again for servers_[2]
ports.clear();
ports.emplace_back(servers_[2]->port_);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** SET [2] *******");
WaitForServer(stub, 2, DEBUG_LOCATION);
EXPECT_EQ(servers_[0]->service_.request_count(), 0);
EXPECT_EQ(servers_[1]->service_.request_count(), 0);
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, PickFirstUpdateSuperset) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("pick_first");
auto stub = BuildStub(channel);
std::vector<int> ports;
// Perform one RPC against the first server.
ports.emplace_back(servers_[0]->port_);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** SET [0] *******");
CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(servers_[0]->service_.request_count(), 1);
servers_[0]->service_.ResetCounters();
// Send and superset update
ports.clear();
ports.emplace_back(servers_[1]->port_);
ports.emplace_back(servers_[0]->port_);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** SET superset *******");
CheckRpcSendOk(stub, DEBUG_LOCATION);
// We stick to the previously connected server.
WaitForServer(stub, 0, DEBUG_LOCATION);
EXPECT_EQ(0, servers_[1]->service_.request_count());
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, PickFirstManyUpdates) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("pick_first");
auto stub = BuildStub(channel);
std::vector<int> ports;
for (size_t i = 0; i < servers_.size(); ++i) {
ports.emplace_back(servers_[i]->port_);
}
for (const bool force_creation : {true, false}) {
grpc_subchannel_index_test_only_set_force_creation(force_creation);
gpr_log(GPR_INFO, "Force subchannel creation: %d", force_creation);
for (size_t i = 0; i < 1000; ++i) {
std::shuffle(ports.begin(), ports.end(),
std::mt19937(std::random_device()()));
SetNextResolution(ports);
if (i % 10 == 0) CheckRpcSendOk(stub, DEBUG_LOCATION);
}
}
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, PickFirstReresolutionNoSelected) {
// Prepare the ports for up servers and down servers.
const int kNumServers = 3;
const int kNumAliveServers = 1;
StartServers(kNumAliveServers);
std::vector<int> alive_ports, dead_ports;
for (size_t i = 0; i < kNumServers; ++i) {
if (i < kNumAliveServers) {
alive_ports.emplace_back(servers_[i]->port_);
} else {
dead_ports.emplace_back(grpc_pick_unused_port_or_die());
}
}
auto channel = BuildChannel("pick_first");
auto stub = BuildStub(channel);
// The initial resolution only contains dead ports. There won't be any
// selected subchannel. Re-resolution will return the same result.
SetNextResolution(dead_ports);
gpr_log(GPR_INFO, "****** INITIAL RESOLUTION SET *******");
for (size_t i = 0; i < 10; ++i) CheckRpcSendFailure(stub);
// Set a re-resolution result that contains reachable ports, so that the
// pick_first LB policy can recover soon.
SetNextResolutionUponError(alive_ports);
gpr_log(GPR_INFO, "****** RE-RESOLUTION SET *******");
WaitForServer(stub, 0, DEBUG_LOCATION, true /* ignore_failure */);
CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(servers_[0]->service_.request_count(), 1);
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, PickFirstReconnectWithoutNewResolverResult) {
std::vector<int> ports = {grpc_pick_unused_port_or_die()};
StartServers(1, ports);
auto channel = BuildChannel("pick_first");
auto stub = BuildStub(channel);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** INITIAL CONNECTION *******");
WaitForServer(stub, 0, DEBUG_LOCATION);
gpr_log(GPR_INFO, "****** STOPPING SERVER ******");
servers_[0]->Shutdown();
EXPECT_TRUE(WaitForChannelNotReady(channel.get()));
gpr_log(GPR_INFO, "****** RESTARTING SERVER ******");
servers_.clear();
StartServers(1, ports);
WaitForServer(stub, 0, DEBUG_LOCATION);
}
TEST_F(ClientLbEnd2endTest,
PickFirstReconnectWithoutNewResolverResultStartsFromTopOfList) {
std::vector<int> ports = {grpc_pick_unused_port_or_die(),
grpc_pick_unused_port_or_die()};
CreateServers(2, ports);
StartServer(1);
auto channel = BuildChannel("pick_first");
auto stub = BuildStub(channel);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** INITIAL CONNECTION *******");
WaitForServer(stub, 1, DEBUG_LOCATION);
gpr_log(GPR_INFO, "****** STOPPING SERVER ******");
servers_[1]->Shutdown();
EXPECT_TRUE(WaitForChannelNotReady(channel.get()));
gpr_log(GPR_INFO, "****** STARTING BOTH SERVERS ******");
servers_.clear();
StartServers(2, ports);
WaitForServer(stub, 0, DEBUG_LOCATION);
}
TEST_F(ClientLbEnd2endTest, PickFirstCheckStateBeforeStartWatch) {
std::vector<int> ports = {grpc_pick_unused_port_or_die()};
StartServers(1, ports);
auto channel_1 = BuildChannel("pick_first");
auto stub_1 = BuildStub(channel_1);
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** RESOLUTION SET FOR CHANNEL 1 *******");
WaitForServer(stub_1, 0, DEBUG_LOCATION);
gpr_log(GPR_INFO, "****** CHANNEL 1 CONNECTED *******");
servers_[0]->Shutdown();
// Channel 1 will receive a re-resolution containing the same server. It will
// create a new subchannel and hold a ref to it.
servers_.clear();
StartServers(1, ports);
gpr_log(GPR_INFO, "****** SERVER RESTARTED *******");
auto channel_2 = BuildChannel("pick_first");
auto stub_2 = BuildStub(channel_2);
// TODO(juanlishen): This resolution result will only be visible to channel 2
// since the response generator is only associated with channel 2 now. We
// should change the response generator to be able to deliver updates to
// multiple channels at once.
SetNextResolution(ports);
gpr_log(GPR_INFO, "****** RESOLUTION SET FOR CHANNEL 2 *******");
WaitForServer(stub_2, 0, DEBUG_LOCATION, true);
gpr_log(GPR_INFO, "****** CHANNEL 2 CONNECTED *******");
servers_[0]->Shutdown();
// Wait until the disconnection has triggered the connectivity notification.
// Otherwise, the subchannel may be picked for next call but will fail soon.
EXPECT_TRUE(WaitForChannelNotReady(channel_2.get()));
// Channel 2 will also receive a re-resolution containing the same server.
// Both channels will ref the same subchannel that failed.
servers_.clear();
StartServers(1, ports);
gpr_log(GPR_INFO, "****** SERVER RESTARTED AGAIN *******");
gpr_log(GPR_INFO, "****** CHANNEL 2 STARTING A CALL *******");
// The first call after the server restart will succeed.
CheckRpcSendOk(stub_2, DEBUG_LOCATION);
gpr_log(GPR_INFO, "****** CHANNEL 2 FINISHED A CALL *******");
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel_1->GetLoadBalancingPolicyName());
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel_2->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, RoundRobin) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
std::vector<int> ports;
for (const auto& server : servers_) {
ports.emplace_back(server->port_);
}
SetNextResolution(ports);
// Wait until all backends are ready.
do {
CheckRpcSendOk(stub, DEBUG_LOCATION);
} while (!SeenAllServers());
ResetCounters();
// "Sync" to the end of the list. Next sequence of picks will start at the
// first server (index 0).
WaitForServer(stub, servers_.size() - 1, DEBUG_LOCATION);
std::vector<int> connection_order;
for (size_t i = 0; i < servers_.size(); ++i) {
CheckRpcSendOk(stub, DEBUG_LOCATION);
UpdateConnectionOrder(servers_, &connection_order);
}
// Backends should be iterated over in the order in which the addresses were
// given.
const auto expected = std::vector<int>{0, 1, 2};
EXPECT_EQ(expected, connection_order);
// Check LB policy name for the channel.
EXPECT_EQ("round_robin", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, RoundRobinProcessPending) {
StartServers(1); // Single server
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
SetNextResolution({servers_[0]->port_});
WaitForServer(stub, 0, DEBUG_LOCATION);
// Create a new channel and its corresponding RR LB policy, which will pick
// the subchannels in READY state from the previous RPC against the same
// target (even if it happened over a different channel, because subchannels
// are globally reused). Progress should happen without any transition from
// this READY state.
auto second_channel = BuildChannel("round_robin");
auto second_stub = BuildStub(second_channel);
SetNextResolution({servers_[0]->port_});
CheckRpcSendOk(second_stub, DEBUG_LOCATION);
}
TEST_F(ClientLbEnd2endTest, RoundRobinUpdates) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
std::vector<int> ports;
// Start with a single server.
ports.emplace_back(servers_[0]->port_);
SetNextResolution(ports);
WaitForServer(stub, 0, DEBUG_LOCATION);
// Send RPCs. They should all go servers_[0]
for (size_t i = 0; i < 10; ++i) CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(10, servers_[0]->service_.request_count());
EXPECT_EQ(0, servers_[1]->service_.request_count());
EXPECT_EQ(0, servers_[2]->service_.request_count());
servers_[0]->service_.ResetCounters();
// And now for the second server.
ports.clear();
ports.emplace_back(servers_[1]->port_);
SetNextResolution(ports);
// Wait until update has been processed, as signaled by the second backend
// receiving a request.
EXPECT_EQ(0, servers_[1]->service_.request_count());
WaitForServer(stub, 1, DEBUG_LOCATION);
for (size_t i = 0; i < 10; ++i) CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(0, servers_[0]->service_.request_count());
EXPECT_EQ(10, servers_[1]->service_.request_count());
EXPECT_EQ(0, servers_[2]->service_.request_count());
servers_[1]->service_.ResetCounters();
// ... and for the last server.
ports.clear();
ports.emplace_back(servers_[2]->port_);
SetNextResolution(ports);
WaitForServer(stub, 2, DEBUG_LOCATION);
for (size_t i = 0; i < 10; ++i) CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(0, servers_[0]->service_.request_count());
EXPECT_EQ(0, servers_[1]->service_.request_count());
EXPECT_EQ(10, servers_[2]->service_.request_count());
servers_[2]->service_.ResetCounters();
// Back to all servers.
ports.clear();
ports.emplace_back(servers_[0]->port_);
ports.emplace_back(servers_[1]->port_);
ports.emplace_back(servers_[2]->port_);
SetNextResolution(ports);
WaitForServer(stub, 0, DEBUG_LOCATION);
WaitForServer(stub, 1, DEBUG_LOCATION);
WaitForServer(stub, 2, DEBUG_LOCATION);
// Send three RPCs, one per server.
for (size_t i = 0; i < 3; ++i) CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(1, servers_[0]->service_.request_count());
EXPECT_EQ(1, servers_[1]->service_.request_count());
EXPECT_EQ(1, servers_[2]->service_.request_count());
// An empty update will result in the channel going into TRANSIENT_FAILURE.
ports.clear();
SetNextResolution(ports);
grpc_connectivity_state channel_state;
do {
channel_state = channel->GetState(true /* try to connect */);
} while (channel_state == GRPC_CHANNEL_READY);
GPR_ASSERT(channel_state != GRPC_CHANNEL_READY);
servers_[0]->service_.ResetCounters();
// Next update introduces servers_[1], making the channel recover.
ports.clear();
ports.emplace_back(servers_[1]->port_);
SetNextResolution(ports);
WaitForServer(stub, 1, DEBUG_LOCATION);
channel_state = channel->GetState(false /* try to connect */);
GPR_ASSERT(channel_state == GRPC_CHANNEL_READY);
// Check LB policy name for the channel.
EXPECT_EQ("round_robin", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, RoundRobinUpdateInError) {
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
std::vector<int> ports;
// Start with a single server.
ports.emplace_back(servers_[0]->port_);
SetNextResolution(ports);
WaitForServer(stub, 0, DEBUG_LOCATION);
// Send RPCs. They should all go to servers_[0]
for (size_t i = 0; i < 10; ++i) SendRpc(stub);
EXPECT_EQ(10, servers_[0]->service_.request_count());
EXPECT_EQ(0, servers_[1]->service_.request_count());
EXPECT_EQ(0, servers_[2]->service_.request_count());
servers_[0]->service_.ResetCounters();
// Shutdown one of the servers to be sent in the update.
servers_[1]->Shutdown(false);
ports.emplace_back(servers_[1]->port_);
ports.emplace_back(servers_[2]->port_);
SetNextResolution(ports);
WaitForServer(stub, 0, DEBUG_LOCATION);
WaitForServer(stub, 2, DEBUG_LOCATION);
// Send three RPCs, one per server.
for (size_t i = 0; i < kNumServers; ++i) SendRpc(stub);
// The server in shutdown shouldn't receive any.
EXPECT_EQ(0, servers_[1]->service_.request_count());
}
TEST_F(ClientLbEnd2endTest, RoundRobinManyUpdates) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
std::vector<int> ports;
for (size_t i = 0; i < servers_.size(); ++i) {
ports.emplace_back(servers_[i]->port_);
}
for (size_t i = 0; i < 1000; ++i) {
std::shuffle(ports.begin(), ports.end(),
std::mt19937(std::random_device()()));
SetNextResolution(ports);
if (i % 10 == 0) CheckRpcSendOk(stub, DEBUG_LOCATION);
}
// Check LB policy name for the channel.
EXPECT_EQ("round_robin", channel->GetLoadBalancingPolicyName());
}
TEST_F(ClientLbEnd2endTest, RoundRobinConcurrentUpdates) {
// TODO(dgq): replicate the way internal testing exercises the concurrent
// update provisions of RR.
}
TEST_F(ClientLbEnd2endTest, RoundRobinReresolve) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
std::vector<int> first_ports;
std::vector<int> second_ports;
first_ports.reserve(kNumServers);
for (int i = 0; i < kNumServers; ++i) {
first_ports.push_back(grpc_pick_unused_port_or_die());
}
second_ports.reserve(kNumServers);
for (int i = 0; i < kNumServers; ++i) {
second_ports.push_back(grpc_pick_unused_port_or_die());
}
StartServers(kNumServers, first_ports);
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
SetNextResolution(first_ports);
// Send a number of RPCs, which succeed.
for (size_t i = 0; i < 100; ++i) {
CheckRpcSendOk(stub, DEBUG_LOCATION);
}
// Kill all servers
gpr_log(GPR_INFO, "****** ABOUT TO KILL SERVERS *******");
for (size_t i = 0; i < servers_.size(); ++i) {
servers_[i]->Shutdown(true);
}
gpr_log(GPR_INFO, "****** SERVERS KILLED *******");
gpr_log(GPR_INFO, "****** SENDING DOOMED REQUESTS *******");
// Client requests should fail. Send enough to tickle all subchannels.
for (size_t i = 0; i < servers_.size(); ++i) CheckRpcSendFailure(stub);
gpr_log(GPR_INFO, "****** DOOMED REQUESTS SENT *******");
// Bring servers back up on a different set of ports. We need to do this to be
// sure that the eventual success is *not* due to subchannel reconnection
// attempts and that an actual re-resolution has happened as a result of the
// RR policy going into transient failure when all its subchannels become
// unavailable (in transient failure as well).
gpr_log(GPR_INFO, "****** RESTARTING SERVERS *******");
StartServers(kNumServers, second_ports);
// Don't notify of the update. Wait for the LB policy's re-resolution to
// "pull" the new ports.
SetNextResolutionUponError(second_ports);
gpr_log(GPR_INFO, "****** SERVERS RESTARTED *******");
gpr_log(GPR_INFO, "****** SENDING REQUEST TO SUCCEED *******");
// Client request should eventually (but still fairly soon) succeed.
const gpr_timespec deadline = grpc_timeout_seconds_to_deadline(5);
gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
while (gpr_time_cmp(deadline, now) > 0) {
if (SendRpc(stub)) break;
now = gpr_now(GPR_CLOCK_MONOTONIC);
}
GPR_ASSERT(gpr_time_cmp(deadline, now) > 0);
}
TEST_F(ClientLbEnd2endTest, RoundRobinSingleReconnect) {
const int kNumServers = 3;
StartServers(kNumServers);
const auto ports = GetServersPorts();
auto channel = BuildChannel("round_robin");
auto stub = BuildStub(channel);
SetNextResolution(ports);
for (size_t i = 0; i < kNumServers; ++i)
WaitForServer(stub, i, DEBUG_LOCATION);
for (size_t i = 0; i < servers_.size(); ++i) {
CheckRpcSendOk(stub, DEBUG_LOCATION);
EXPECT_EQ(1, servers_[i]->service_.request_count()) << "for backend #" << i;
}
// One request should have gone to each server.
for (size_t i = 0; i < servers_.size(); ++i) {
EXPECT_EQ(1, servers_[i]->service_.request_count());
}
const auto pre_death = servers_[0]->service_.request_count();
// Kill the first server.
servers_[0]->Shutdown(true);
// Client request still succeed. May need retrying if RR had returned a pick
// before noticing the change in the server's connectivity.
while (!SendRpc(stub)) {
} // Retry until success.
// Send a bunch of RPCs that should succeed.
for (int i = 0; i < 10 * kNumServers; ++i) {
CheckRpcSendOk(stub, DEBUG_LOCATION);
}
const auto post_death = servers_[0]->service_.request_count();
// No requests have gone to the deceased server.
EXPECT_EQ(pre_death, post_death);
// Bring the first server back up.
servers_[0].reset(new ServerData(ports[0]));
StartServer(0);
// Requests should start arriving at the first server either right away (if
// the server managed to start before the RR policy retried the subchannel) or
// after the subchannel retry delay otherwise (RR's subchannel retried before
// the server was fully back up).
WaitForServer(stub, 0, DEBUG_LOCATION);
}
} // namespace
} // namespace testing
} // namespace grpc
int main(int argc, char** argv) {
::testing::InitGoogleTest(&argc, argv);
grpc_test_init(argc, argv);
grpc_init();
const auto result = RUN_ALL_TESTS();
grpc_shutdown();
return result;
}
|