-
Notifications
You must be signed in to change notification settings - Fork 5.6k
/
replication_coordinator_impl.cpp
3885 lines (3331 loc) · 157 KB
/
replication_coordinator_impl.cpp
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
998
999
1000
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kReplication
#include "mongo/platform/basic.h"
#include "mongo/db/repl/replication_coordinator_impl.h"
#include <algorithm>
#include <limits>
#include "mongo/base/status.h"
#include "mongo/client/fetcher.h"
#include "mongo/db/audit.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/concurrency/d_concurrency.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/logical_clock.h"
#include "mongo/db/logical_time.h"
#include "mongo/db/logical_time_validator.h"
#include "mongo/db/operation_context_noop.h"
#include "mongo/db/repl/check_quorum_for_config_change.h"
#include "mongo/db/repl/data_replicator_external_state_initial_sync.h"
#include "mongo/db/repl/elect_cmd_runner.h"
#include "mongo/db/repl/freshness_checker.h"
#include "mongo/db/repl/handshake_args.h"
#include "mongo/db/repl/is_master_response.h"
#include "mongo/db/repl/last_vote.h"
#include "mongo/db/repl/member_data.h"
#include "mongo/db/repl/read_concern_args.h"
#include "mongo/db/repl/repl_client_info.h"
#include "mongo/db/repl/repl_set_config_checks.h"
#include "mongo/db/repl/repl_set_heartbeat_args.h"
#include "mongo/db/repl/repl_set_heartbeat_args_v1.h"
#include "mongo/db/repl/repl_set_heartbeat_response.h"
#include "mongo/db/repl/repl_set_html_summary.h"
#include "mongo/db/repl/repl_set_request_votes_args.h"
#include "mongo/db/repl/repl_settings.h"
#include "mongo/db/repl/replication_process.h"
#include "mongo/db/repl/rslog.h"
#include "mongo/db/repl/storage_interface.h"
#include "mongo/db/repl/topology_coordinator.h"
#include "mongo/db/repl/update_position_args.h"
#include "mongo/db/repl/vote_requester.h"
#include "mongo/db/server_options.h"
#include "mongo/db/server_parameters.h"
#include "mongo/db/write_concern.h"
#include "mongo/db/write_concern_options.h"
#include "mongo/executor/connection_pool_stats.h"
#include "mongo/executor/network_interface.h"
#include "mongo/rpc/metadata/oplog_query_metadata.h"
#include "mongo/rpc/metadata/repl_set_metadata.h"
#include "mongo/stdx/functional.h"
#include "mongo/stdx/mutex.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/fail_point_service.h"
#include "mongo/util/log.h"
#include "mongo/util/scopeguard.h"
#include "mongo/util/stacktrace.h"
#include "mongo/util/time_support.h"
#include "mongo/util/timer.h"
namespace mongo {
namespace repl {
MONGO_FP_DECLARE(stepdownHangBeforePerformingPostMemberStateUpdateActions);
MONGO_FP_DECLARE(transitionToPrimaryHangBeforeTakingGlobalExclusiveLock);
using CallbackArgs = executor::TaskExecutor::CallbackArgs;
using CallbackFn = executor::TaskExecutor::CallbackFn;
using CallbackHandle = executor::TaskExecutor::CallbackHandle;
using EventHandle = executor::TaskExecutor::EventHandle;
using executor::NetworkInterface;
using NextAction = Fetcher::NextAction;
namespace {
const char kLocalDB[] = "local";
// Overrides _canAcceptLocalWrites for the decorated OperationContext.
const OperationContext::Decoration<bool> alwaysAllowNonLocalWrites =
OperationContext::declareDecoration<bool>();
MONGO_EXPORT_SERVER_PARAMETER(numInitialSyncAttempts, int, 10);
MONGO_EXPORT_SERVER_PARAMETER(enableElectionHandoff, bool, true);
// Number of seconds between noop writer writes.
MONGO_EXPORT_STARTUP_SERVER_PARAMETER(periodicNoopIntervalSecs, int, 10);
MONGO_INITIALIZER(periodicNoopIntervalSecs)(InitializerContext*) {
if (periodicNoopIntervalSecs <= 0) {
return Status(ErrorCodes::BadValue,
str::stream() << "Periodic noop interval must be greater than 0 seconds: "
<< periodicNoopIntervalSecs);
} else if (periodicNoopIntervalSecs > 10) {
return Status(ErrorCodes::BadValue,
str::stream()
<< "Periodic noop interval must be less than or equal to 10 seconds: "
<< periodicNoopIntervalSecs);
}
return Status::OK();
}
/**
* Allows non-local writes despite _canAcceptNonlocalWrites being false on a single OperationContext
* while in scope.
*
* Resets to original value when leaving scope so it is safe to nest.
*/
class AllowNonLocalWritesBlock {
MONGO_DISALLOW_COPYING(AllowNonLocalWritesBlock);
public:
AllowNonLocalWritesBlock(OperationContext* opCtx)
: _opCtx(opCtx), _initialState(alwaysAllowNonLocalWrites(_opCtx)) {
alwaysAllowNonLocalWrites(_opCtx) = true;
}
~AllowNonLocalWritesBlock() {
alwaysAllowNonLocalWrites(_opCtx) = _initialState;
}
private:
OperationContext* const _opCtx;
const bool _initialState;
};
void lockAndCall(stdx::unique_lock<stdx::mutex>* lk, const stdx::function<void()>& fn) {
if (!lk->owns_lock()) {
lk->lock();
}
fn();
}
/**
* Implements the force-reconfig behavior of incrementing config version by a large random
* number.
*/
BSONObj incrementConfigVersionByRandom(BSONObj config) {
BSONObjBuilder builder;
for (BSONObjIterator iter(config); iter.more(); iter.next()) {
BSONElement elem = *iter;
if (elem.fieldNameStringData() == ReplSetConfig::kVersionFieldName && elem.isNumber()) {
std::unique_ptr<SecureRandom> generator(SecureRandom::create());
const int random = std::abs(static_cast<int>(generator->nextInt64()) % 100000);
builder.appendIntOrLL(ReplSetConfig::kVersionFieldName,
elem.numberLong() + 10000 + random);
} else {
builder.append(elem);
}
}
return builder.obj();
}
// This is a special flag that allows for testing of snapshot behavior by skipping the replication
// related checks and isolating the storage/query side of snapshotting.
// SERVER-31304 rename this parameter to something more appropriate.
bool testingSnapshotBehaviorInIsolation = false;
ExportedServerParameter<bool, ServerParameterType::kStartupOnly> TestingSnapshotBehaviorInIsolation(
ServerParameterSet::getGlobal(),
"testingSnapshotBehaviorInIsolation",
&testingSnapshotBehaviorInIsolation);
} // namespace
ReplicationCoordinatorImpl::Waiter::Waiter(OpTime _opTime, const WriteConcernOptions* _writeConcern)
: opTime(std::move(_opTime)), writeConcern(_writeConcern) {}
BSONObj ReplicationCoordinatorImpl::Waiter::toBSON() const {
BSONObjBuilder bob;
bob.append("opTime", opTime.toBSON());
if (writeConcern) {
bob.append("writeConcern", writeConcern->toBSON());
}
return bob.obj();
};
std::string ReplicationCoordinatorImpl::Waiter::toString() const {
return toBSON().toString();
};
ReplicationCoordinatorImpl::ThreadWaiter::ThreadWaiter(OpTime _opTime,
const WriteConcernOptions* _writeConcern,
stdx::condition_variable* _condVar)
: Waiter(_opTime, _writeConcern), condVar(_condVar) {}
void ReplicationCoordinatorImpl::ThreadWaiter::notify_inlock() {
invariant(condVar);
condVar->notify_all();
}
ReplicationCoordinatorImpl::CallbackWaiter::CallbackWaiter(OpTime _opTime,
FinishFunc _finishCallback)
: Waiter(_opTime, nullptr), finishCallback(std::move(_finishCallback)) {}
void ReplicationCoordinatorImpl::CallbackWaiter::notify_inlock() {
invariant(finishCallback);
finishCallback();
}
class ReplicationCoordinatorImpl::WaiterGuard {
public:
/**
* Constructor takes the list of waiters and enqueues itself on the list, removing itself
* in the destructor.
*
* Usually waiters will be signaled and removed when their criteria are satisfied, but
* wait_until() with timeout may signal waiters earlier and this guard will remove the waiter
* properly.
*
* _list is guarded by ReplicationCoordinatorImpl::_mutex, thus it is illegal to construct one
* of these without holding _mutex
*/
WaiterGuard(WaiterList* list, Waiter* waiter) : _list(list), _waiter(waiter) {
list->add_inlock(_waiter);
}
~WaiterGuard() {
_list->remove_inlock(_waiter);
}
private:
WaiterList* _list;
Waiter* _waiter;
};
void ReplicationCoordinatorImpl::WaiterList::add_inlock(WaiterType waiter) {
_list.push_back(waiter);
}
void ReplicationCoordinatorImpl::WaiterList::signalAndRemoveIf_inlock(
stdx::function<bool(WaiterType)> func) {
// Only advance iterator when the element doesn't match.
for (auto it = _list.begin(); it != _list.end();) {
if (!func(*it)) {
++it;
continue;
}
WaiterType waiter = std::move(*it);
if (it == std::prev(_list.end())) {
// Iterator will be invalid after erasing the last element, so set it to the
// next one (i.e. end()).
it = _list.erase(it);
} else {
// Iterator is still valid after pop_back().
std::swap(*it, _list.back());
_list.pop_back();
}
// It's important to call notify() after the waiter has been removed from the list
// since notify() might remove the waiter itself.
waiter->notify_inlock();
}
}
void ReplicationCoordinatorImpl::WaiterList::signalAndRemoveAll_inlock() {
std::vector<WaiterType> list = std::move(_list);
// Call notify() after removing the waiters from the list.
for (auto& waiter : list) {
waiter->notify_inlock();
}
}
bool ReplicationCoordinatorImpl::WaiterList::remove_inlock(WaiterType waiter) {
auto it = std::find(_list.begin(), _list.end(), waiter);
if (it == _list.end()) {
return false;
}
std::swap(*it, _list.back());
_list.pop_back();
return true;
}
namespace {
ReplicationCoordinator::Mode getReplicationModeFromSettings(const ReplSettings& settings) {
if (settings.usingReplSets()) {
return ReplicationCoordinator::modeReplSet;
}
if (settings.isMaster() || settings.isSlave()) {
return ReplicationCoordinator::modeMasterSlave;
}
return ReplicationCoordinator::modeNone;
}
InitialSyncerOptions createInitialSyncerOptions(
ReplicationCoordinator* replCoord, ReplicationCoordinatorExternalState* externalState) {
InitialSyncerOptions options;
options.getMyLastOptime = [replCoord]() { return replCoord->getMyLastAppliedOpTime(); };
options.setMyLastOptime = [replCoord, externalState](
const OpTime& opTime, ReplicationCoordinator::DataConsistency consistency) {
replCoord->setMyLastAppliedOpTimeForward(opTime, consistency);
externalState->setGlobalTimestamp(replCoord->getServiceContext(), opTime.getTimestamp());
};
options.resetOptimes = [replCoord]() { replCoord->resetMyLastOpTimes(); };
options.getSlaveDelay = [replCoord]() { return replCoord->getSlaveDelaySecs(); };
options.syncSourceSelector = replCoord;
options.batchLimits = externalState->getInitialSyncBatchLimits();
options.oplogFetcherMaxFetcherRestarts =
externalState->getOplogFetcherInitialSyncMaxFetcherRestarts();
return options;
}
} // namespace
ReplicationCoordinatorImpl::ReplicationCoordinatorImpl(
ServiceContext* service,
const ReplSettings& settings,
std::unique_ptr<ReplicationCoordinatorExternalState> externalState,
std::unique_ptr<executor::TaskExecutor> executor,
std::unique_ptr<TopologyCoordinator> topCoord,
ReplicationProcess* replicationProcess,
StorageInterface* storage,
int64_t prngSeed)
: _service(service),
_settings(settings),
_replMode(getReplicationModeFromSettings(settings)),
_topCoord(std::move(topCoord)),
_replExecutor(std::move(executor)),
_externalState(std::move(externalState)),
_inShutdown(false),
_memberState(MemberState::RS_STARTUP),
_rsConfigState(kConfigPreStart),
_selfIndex(-1),
_sleptLastElection(false),
_canAcceptNonLocalWrites(!(settings.usingReplSets() || settings.isSlave())),
_canServeNonLocalReads(0U),
_replicationProcess(replicationProcess),
_storage(storage),
_random(prngSeed) {
_termShadow.store(OpTime::kUninitializedTerm);
invariant(_service);
if (!isReplEnabled()) {
return;
}
_externalState->setupNoopWriter(Seconds(periodicNoopIntervalSecs));
}
ReplicationCoordinatorImpl::~ReplicationCoordinatorImpl() = default;
void ReplicationCoordinatorImpl::waitForStartUpComplete_forTest() {
_waitForStartUpComplete();
}
void ReplicationCoordinatorImpl::_waitForStartUpComplete() {
CallbackHandle handle;
{
stdx::unique_lock<stdx::mutex> lk(_mutex);
while (_rsConfigState == kConfigPreStart || _rsConfigState == kConfigStartingUp) {
_rsConfigStateChange.wait(lk);
}
handle = _finishLoadLocalConfigCbh;
}
if (handle.isValid()) {
_replExecutor->wait(handle);
}
}
ReplSetConfig ReplicationCoordinatorImpl::getReplicaSetConfig_forTest() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _rsConfig;
}
Date_t ReplicationCoordinatorImpl::getElectionTimeout_forTest() const {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (!_handleElectionTimeoutCbh.isValid()) {
return Date_t();
}
return _handleElectionTimeoutWhen;
}
Milliseconds ReplicationCoordinatorImpl::getRandomizedElectionOffset_forTest() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _getRandomizedElectionOffset_inlock();
}
boost::optional<Date_t> ReplicationCoordinatorImpl::getPriorityTakeover_forTest() const {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (!_priorityTakeoverCbh.isValid()) {
return boost::none;
}
return _priorityTakeoverWhen;
}
boost::optional<Date_t> ReplicationCoordinatorImpl::getCatchupTakeover_forTest() const {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (!_catchupTakeoverCbh.isValid()) {
return boost::none;
}
return _catchupTakeoverWhen;
}
executor::TaskExecutor::CallbackHandle ReplicationCoordinatorImpl::getCatchupTakeoverCbh_forTest()
const {
return _catchupTakeoverCbh;
}
OpTime ReplicationCoordinatorImpl::getCurrentCommittedSnapshotOpTime() const {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _getCurrentCommittedSnapshotOpTime_inlock();
}
OpTime ReplicationCoordinatorImpl::_getCurrentCommittedSnapshotOpTime_inlock() const {
if (_currentCommittedSnapshot) {
return _currentCommittedSnapshot.get();
}
return OpTime();
}
LogicalTime ReplicationCoordinatorImpl::_getCurrentCommittedLogicalTime_inlock() const {
return LogicalTime(_getCurrentCommittedSnapshotOpTime_inlock().getTimestamp());
}
void ReplicationCoordinatorImpl::appendDiagnosticBSON(mongo::BSONObjBuilder* bob) {
BSONObjBuilder eBuilder(bob->subobjStart("executor"));
_replExecutor->appendDiagnosticBSON(&eBuilder);
}
void ReplicationCoordinatorImpl::appendConnectionStats(executor::ConnectionPoolStats* stats) const {
_replExecutor->appendConnectionStats(stats);
}
bool ReplicationCoordinatorImpl::_startLoadLocalConfig(OperationContext* opCtx) {
_replicationProcess->getConsistencyMarkers()->initializeMinValidDocument(opCtx);
StatusWith<LastVote> lastVote = _externalState->loadLocalLastVoteDocument(opCtx);
if (!lastVote.isOK()) {
if (lastVote.getStatus() == ErrorCodes::NoMatchingDocument) {
log() << "Did not find local voted for document at startup.";
} else {
severe() << "Error loading local voted for document at startup; "
<< lastVote.getStatus();
fassertFailedNoTrace(40367);
}
} else {
stdx::lock_guard<stdx::mutex> lk(_mutex);
_topCoord->loadLastVote(lastVote.getValue());
}
// Check that we have a local Rollback ID. If we do not have one, create one.
auto status = _replicationProcess->refreshRollbackID(opCtx);
if (!status.isOK()) {
if (status == ErrorCodes::NamespaceNotFound) {
log() << "Did not find local Rollback ID document at startup. Creating one.";
auto initializingStatus = _replicationProcess->initializeRollbackID(opCtx);
fassertStatusOK(40424, initializingStatus);
} else {
severe() << "Error loading local Rollback ID document at startup; " << status;
fassertFailedNoTrace(40428);
}
}
StatusWith<BSONObj> cfg = _externalState->loadLocalConfigDocument(opCtx);
if (!cfg.isOK()) {
log() << "Did not find local replica set configuration document at startup; "
<< cfg.getStatus();
return true;
}
ReplSetConfig localConfig;
status = localConfig.initialize(cfg.getValue());
if (!status.isOK()) {
error() << "Locally stored replica set configuration does not parse; See "
"http://www.mongodb.org/dochub/core/recover-replica-set-from-invalid-config "
"for information on how to recover from this. Got \""
<< status << "\" while parsing " << cfg.getValue();
fassertFailedNoTrace(28545);
}
// Read the last op from the oplog after cleaning up any partially applied batches.
_replicationProcess->getReplicationRecovery()->recoverFromOplog(opCtx);
auto lastOpTimeStatus = _externalState->loadLastOpTime(opCtx);
// Use a callback here, because _finishLoadLocalConfig calls isself() which requires
// that the server's networking layer be up and running and accepting connections, which
// doesn't happen until startReplication finishes.
auto handle =
_replExecutor->scheduleWork(stdx::bind(&ReplicationCoordinatorImpl::_finishLoadLocalConfig,
this,
stdx::placeholders::_1,
localConfig,
lastOpTimeStatus,
lastVote));
if (handle == ErrorCodes::ShutdownInProgress) {
handle = CallbackHandle{};
}
fassertStatusOK(40446, handle);
stdx::lock_guard<stdx::mutex> lk(_mutex);
_finishLoadLocalConfigCbh = std::move(handle.getValue());
return false;
}
void ReplicationCoordinatorImpl::_finishLoadLocalConfig(
const executor::TaskExecutor::CallbackArgs& cbData,
const ReplSetConfig& localConfig,
const StatusWith<OpTime>& lastOpTimeStatus,
const StatusWith<LastVote>& lastVoteStatus) {
if (!cbData.status.isOK()) {
LOG(1) << "Loading local replica set configuration failed due to " << cbData.status;
return;
}
StatusWith<int> myIndex =
validateConfigForStartUp(_externalState.get(), localConfig, getServiceContext());
if (!myIndex.isOK()) {
if (myIndex.getStatus() == ErrorCodes::NodeNotFound ||
myIndex.getStatus() == ErrorCodes::DuplicateKey) {
warning() << "Locally stored replica set configuration does not have a valid entry "
"for the current node; waiting for reconfig or remote heartbeat; Got \""
<< myIndex.getStatus() << "\" while validating " << localConfig.toBSON();
myIndex = StatusWith<int>(-1);
} else {
error() << "Locally stored replica set configuration is invalid; See "
"http://www.mongodb.org/dochub/core/recover-replica-set-from-invalid-config"
" for information on how to recover from this. Got \""
<< myIndex.getStatus() << "\" while validating " << localConfig.toBSON();
fassertFailedNoTrace(28544);
}
}
if (localConfig.getReplSetName() != _settings.ourSetName()) {
warning() << "Local replica set configuration document reports set name of "
<< localConfig.getReplSetName() << ", but command line reports "
<< _settings.ourSetName() << "; waitng for reconfig or remote heartbeat";
myIndex = StatusWith<int>(-1);
}
if (serverGlobalParams.enableMajorityReadConcern && localConfig.containsArbiter()) {
log() << startupWarningsLog;
log() << "** WARNING: This replica set uses arbiters, but readConcern:majority is enabled "
<< startupWarningsLog;
log() << "** for this node. This is not a recommended configuration. Please see "
<< startupWarningsLog;
log() << "** https://dochub.mongodb.org/core/psa-disable-rc-majority-3.6"
<< startupWarningsLog;
log() << startupWarningsLog;
}
// Do not check optime, if this node is an arbiter.
bool isArbiter =
myIndex.getValue() != -1 && localConfig.getMemberAt(myIndex.getValue()).isArbiter();
OpTime lastOpTime;
if (!isArbiter) {
if (!lastOpTimeStatus.isOK()) {
warning() << "Failed to load timestamp of most recently applied operation: "
<< lastOpTimeStatus.getStatus();
} else {
lastOpTime = lastOpTimeStatus.getValue();
}
} else {
// The node is an arbiter hence will not need logical clock for external operations.
LogicalClock::get(getServiceContext())->setEnabled(false);
auto validator = LogicalTimeValidator::get(getServiceContext());
if (validator) {
validator->stopKeyManager();
}
}
long long term = OpTime::kUninitializedTerm;
if (localConfig.getProtocolVersion() == 1) {
// Restore the current term according to the terms of last oplog entry and last vote.
// The initial term of OpTime() is 0.
term = lastOpTime.getTerm();
if (lastVoteStatus.isOK()) {
long long lastVoteTerm = lastVoteStatus.getValue().getTerm();
if (term < lastVoteTerm) {
term = lastVoteTerm;
}
}
}
auto opCtx = cc().makeOperationContext();
auto consistency = DataConsistency::Inconsistent;
if (!lastOpTime.isNull()) {
// If we have an oplog, it is still possible that our data is not in a consistent state. For
// example, if we are starting up after a crash following a post-rollback RECOVERING state.
// To detect this, we see if our last optime is >= the 'minValid' optime, which
// should be persistent across node crashes.
OpTime minValid = _replicationProcess->getConsistencyMarkers()->getMinValid(opCtx.get());
consistency =
(lastOpTime >= minValid) ? DataConsistency::Consistent : DataConsistency::Inconsistent;
}
stdx::unique_lock<stdx::mutex> lock(_mutex);
invariant(_rsConfigState == kConfigStartingUp);
const PostMemberStateUpdateAction action =
_setCurrentRSConfig_inlock(opCtx.get(), localConfig, myIndex.getValue());
// Set our last applied and durable optimes to the top of the oplog, if we have one.
if (!lastOpTime.isNull()) {
bool isRollbackAllowed = false;
_setMyLastAppliedOpTime_inlock(lastOpTime, isRollbackAllowed, consistency);
_setMyLastDurableOpTime_inlock(lastOpTime, isRollbackAllowed);
_reportUpstream_inlock(std::move(lock)); // unlocks _mutex.
} else {
lock.unlock();
}
_externalState->setGlobalTimestamp(getServiceContext(), lastOpTime.getTimestamp());
{
stdx::lock_guard<stdx::mutex> lk(_mutex);
// Step down is impossible, so we don't need to wait for the returned event.
_updateTerm_inlock(term);
}
LOG(1) << "Current term is now " << term;
_performPostMemberStateUpdateAction(action);
if (!isArbiter) {
_externalState->startThreads(_settings);
_startDataReplication(opCtx.get());
}
}
void ReplicationCoordinatorImpl::_stopDataReplication(OperationContext* opCtx) {
std::shared_ptr<InitialSyncer> initialSyncerCopy;
{
stdx::lock_guard<stdx::mutex> lk(_mutex);
_initialSyncer.swap(initialSyncerCopy);
}
if (initialSyncerCopy) {
LOG(1)
<< "ReplicationCoordinatorImpl::_stopDataReplication calling InitialSyncer::shutdown.";
const auto status = initialSyncerCopy->shutdown();
if (!status.isOK()) {
warning() << "InitialSyncer shutdown failed: " << status;
}
initialSyncerCopy.reset();
// Do not return here, fall through.
}
LOG(1) << "ReplicationCoordinatorImpl::_stopDataReplication calling "
"ReplCoordExtState::stopDataReplication.";
_externalState->stopDataReplication(opCtx);
}
void ReplicationCoordinatorImpl::_startDataReplication(OperationContext* opCtx,
stdx::function<void()> startCompleted) {
// Check to see if we need to do an initial sync.
const auto lastOpTime = getMyLastAppliedOpTime();
const auto needsInitialSync =
lastOpTime.isNull() || _externalState->isInitialSyncFlagSet(opCtx);
if (!needsInitialSync) {
// Start steady replication, since we already have data.
// ReplSetConfig has been installed, so it's either in STARTUP2 or REMOVED.
auto memberState = getMemberState();
invariant(memberState.startup2() || memberState.removed());
invariantOK(setFollowerMode(MemberState::RS_RECOVERING));
_externalState->startSteadyStateReplication(opCtx, this);
return;
}
// Do initial sync.
if (!_externalState->getTaskExecutor()) {
log() << "not running initial sync during test.";
return;
}
auto onCompletion = [this, startCompleted](const StatusWith<OpTimeWithHash>& status) {
{
stdx::lock_guard<stdx::mutex> lock(_mutex);
if (status == ErrorCodes::CallbackCanceled) {
log() << "Initial Sync has been cancelled: " << status.getStatus();
return;
} else if (!status.isOK()) {
if (_inShutdown) {
log() << "Initial Sync failed during shutdown due to " << status.getStatus();
return;
} else {
error() << "Initial sync failed, shutting down now. Restart the server "
"to attempt a new initial sync.";
fassertFailedWithStatusNoTrace(40088, status.getStatus());
}
}
const auto lastApplied = status.getValue();
_setMyLastAppliedOpTime_inlock(lastApplied.opTime, false, DataConsistency::Consistent);
}
// Clear maint. mode.
while (getMaintenanceMode()) {
setMaintenanceMode(false).transitional_ignore();
}
if (startCompleted) {
startCompleted();
}
// Repair local db (to compact it).
auto opCtxHolder = cc().makeOperationContext();
uassertStatusOK(_externalState->runRepairOnLocalDB(opCtxHolder.get()));
// Because initial sync completed, we can only be in STARTUP2, not REMOVED.
// Transition from STARTUP2 to RECOVERING and start the producer and the applier.
invariant(getMemberState().startup2());
invariantOK(setFollowerMode(MemberState::RS_RECOVERING));
_externalState->startSteadyStateReplication(opCtxHolder.get(), this);
};
std::shared_ptr<InitialSyncer> initialSyncerCopy;
try {
{
// Must take the lock to set _initialSyncer, but not call it.
stdx::lock_guard<stdx::mutex> lock(_mutex);
initialSyncerCopy = std::make_shared<InitialSyncer>(
createInitialSyncerOptions(this, _externalState.get()),
stdx::make_unique<DataReplicatorExternalStateInitialSync>(this,
_externalState.get()),
_storage,
_replicationProcess,
onCompletion);
_initialSyncer = initialSyncerCopy;
}
// InitialSyncer::startup() must be called outside lock because it uses features (eg.
// setting the initial sync flag) which depend on the ReplicationCoordinatorImpl.
uassertStatusOK(initialSyncerCopy->startup(opCtx, numInitialSyncAttempts.load()));
} catch (...) {
auto status = exceptionToStatus();
log() << "Initial Sync failed to start: " << status;
if (ErrorCodes::CallbackCanceled == status || ErrorCodes::isShutdownError(status.code())) {
return;
}
fassertFailedWithStatusNoTrace(40354, status);
}
}
void ReplicationCoordinatorImpl::startup(OperationContext* opCtx) {
if (!isReplEnabled()) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
_setConfigState_inlock(kConfigReplicationDisabled);
return;
}
{
OID rid = _externalState->ensureMe(opCtx);
stdx::lock_guard<stdx::mutex> lk(_mutex);
fassert(18822, !_inShutdown);
_setConfigState_inlock(kConfigStartingUp);
_myRID = rid;
_topCoord->getMyMemberData()->setRid(rid);
}
if (!_settings.usingReplSets()) {
// Must be Master/Slave
invariant(_settings.isMaster() || _settings.isSlave());
_externalState->startMasterSlave(opCtx);
return;
}
_replExecutor->startup();
{
stdx::lock_guard<stdx::mutex> lk(_mutex);
_topCoord->setStorageEngineSupportsReadCommitted(
_externalState->isReadCommittedSupportedByStorageEngine(opCtx));
}
bool doneLoadingConfig = _startLoadLocalConfig(opCtx);
if (doneLoadingConfig) {
// If we're not done loading the config, then the config state will be set by
// _finishLoadLocalConfig.
stdx::lock_guard<stdx::mutex> lk(_mutex);
invariant(!_rsConfig.isInitialized());
_setConfigState_inlock(kConfigUninitialized);
}
}
void ReplicationCoordinatorImpl::shutdown(OperationContext* opCtx) {
// Shutdown must:
// * prevent new threads from blocking in awaitReplication
// * wake up all existing threads blocking in awaitReplication
// * Shut down and join the execution resources it owns.
if (!_settings.usingReplSets()) {
return;
}
log() << "shutting down replication subsystems";
// Used to shut down outside of the lock.
std::shared_ptr<InitialSyncer> initialSyncerCopy;
{
stdx::unique_lock<stdx::mutex> lk(_mutex);
fassert(28533, !_inShutdown);
_inShutdown = true;
if (_rsConfigState == kConfigPreStart) {
warning() << "ReplicationCoordinatorImpl::shutdown() called before "
"startup() finished. Shutting down without cleaning up the "
"replication system";
return;
}
if (_rsConfigState == kConfigStartingUp) {
// Wait until we are finished starting up, so that we can cleanly shut everything down.
lk.unlock();
_waitForStartUpComplete();
lk.lock();
fassert(18823, _rsConfigState != kConfigStartingUp);
}
_replicationWaiterList.signalAndRemoveAll_inlock();
_opTimeWaiterList.signalAndRemoveAll_inlock();
_currentCommittedSnapshotCond.notify_all();
_initialSyncer.swap(initialSyncerCopy);
_stepDownWaiters.notify_all();
}
// joining the replication executor is blocking so it must be run outside of the mutex
if (initialSyncerCopy) {
LOG(1) << "ReplicationCoordinatorImpl::shutdown calling InitialSyncer::shutdown.";
const auto status = initialSyncerCopy->shutdown();
if (!status.isOK()) {
warning() << "InitialSyncer shutdown failed: " << status;
}
initialSyncerCopy->join();
initialSyncerCopy.reset();
}
_externalState->shutdown(opCtx);
_replExecutor->shutdown();
_replExecutor->join();
}
const ReplSettings& ReplicationCoordinatorImpl::getSettings() const {
return _settings;
}
ReplicationCoordinator::Mode ReplicationCoordinatorImpl::getReplicationMode() const {
return _replMode;
}
MemberState ReplicationCoordinatorImpl::getMemberState() const {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _getMemberState_inlock();
}
MemberState ReplicationCoordinatorImpl::_getMemberState_inlock() const {
return _memberState;
}
Status ReplicationCoordinatorImpl::waitForMemberState(MemberState expectedState,
Milliseconds timeout) {
if (timeout < Milliseconds(0)) {
return Status(ErrorCodes::BadValue, "Timeout duration cannot be negative");
}
stdx::unique_lock<stdx::mutex> lk(_mutex);
auto pred = [this, expectedState]() { return _memberState == expectedState; };
if (!_memberStateChange.wait_for(lk, timeout.toSystemDuration(), pred)) {
return Status(ErrorCodes::ExceededTimeLimit,
str::stream() << "Timed out waiting for state to become "
<< expectedState.toString()
<< ". Current state is "
<< _memberState.toString());
}
return Status::OK();
}
Seconds ReplicationCoordinatorImpl::getSlaveDelaySecs() const {
stdx::lock_guard<stdx::mutex> lk(_mutex);
invariant(_rsConfig.isInitialized());
if (_selfIndex == -1) {
// We aren't currently in the set. Return 0 seconds so we can clear out the applier's
// queue of work.
return Seconds(0);
}
return _rsConfig.getMemberAt(_selfIndex).getSlaveDelay();
}
void ReplicationCoordinatorImpl::clearSyncSourceBlacklist() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
_topCoord->clearSyncSourceBlacklist();
}
Status ReplicationCoordinatorImpl::setFollowerMode(const MemberState& newState) {
stdx::unique_lock<stdx::mutex> lk(_mutex);
if (newState == _topCoord->getMemberState()) {
return Status::OK();
}
if (_topCoord->getRole() == TopologyCoordinator::Role::kLeader) {
return Status(ErrorCodes::NotSecondary,
"Cannot set follower mode when node is currently the leader");
}
if (auto electionFinishedEvent = _cancelElectionIfNeeded_inlock()) {
// We were a candidate, which means _topCoord believed us to be in state RS_SECONDARY, and
// we know that newState != RS_SECONDARY because we would have returned early, above if
// the old and new state were equal. So, try again after the election is over to
// finish setting the follower mode. We cannot wait for the election to finish here as we
// may be holding a global X lock, so we return a bad status and rely on the caller to
// retry.
return Status(ErrorCodes::ElectionInProgress,
str::stream() << "Cannot set follower mode to " << newState.toString()
<< " because we are in the middle of running an election");
}
_topCoord->setFollowerMode(newState.s);
const PostMemberStateUpdateAction action =
_updateMemberStateFromTopologyCoordinator_inlock(nullptr);
lk.unlock();
_performPostMemberStateUpdateAction(action);
return Status::OK();
}
ReplicationCoordinator::ApplierState ReplicationCoordinatorImpl::getApplierState() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _applierState;
}
void ReplicationCoordinatorImpl::signalDrainComplete(OperationContext* opCtx,
long long termWhenBufferIsEmpty) {
// This logic is a little complicated in order to avoid acquiring the global exclusive lock
// unnecessarily. This is important because the applier may call signalDrainComplete()
// whenever it wants, not only when the ReplicationCoordinator is expecting it.
//
// The steps are:
// 1.) Check to see if we're waiting for this signal. If not, return early.
// 2.) Otherwise, release the mutex while acquiring the global exclusive lock,
// since that might take a while (NB there's a deadlock cycle otherwise, too).
// 3.) Re-check to see if we've somehow left drain mode. If we have not, clear
// producer and applier's states, set the flag allowing non-local database writes and
// drop the mutex. At this point, no writes can occur from other threads, due to the
// global exclusive lock.
// 4.) Drop all temp collections, and log the drops to the oplog.
// 5.) Log transition to primary in the oplog and set that OpTime as the floor for what we will
// consider to be committed.
// 6.) Drop the global exclusive lock.
//
// Because replicatable writes are forbidden while in drain mode, and we don't exit drain
// mode until we have the global exclusive lock, which forbids all other threads from making
// writes, we know that from the time that _canAcceptNonLocalWrites is set until
// this method returns, no external writes will be processed. This is important so that a new
// temp collection isn't introduced on the new primary before we drop all the temp collections.
// When we go to drop all temp collections, we must replicate the drops.
invariant(opCtx->writesAreReplicated());
stdx::unique_lock<stdx::mutex> lk(_mutex);
if (_applierState != ApplierState::Draining) {
return;
}
lk.unlock();
_externalState->onDrainComplete(opCtx);
if (MONGO_FAIL_POINT(transitionToPrimaryHangBeforeTakingGlobalExclusiveLock)) {
log() << "transition to primary - "
"transitionToPrimaryHangBeforeTakingGlobalExclusiveLock fail point enabled. "
"Blocking until fail point is disabled.";
while (MONGO_FAIL_POINT(transitionToPrimaryHangBeforeTakingGlobalExclusiveLock)) {
mongo::sleepsecs(1);
{
stdx::lock_guard<stdx::mutex> lock(_mutex);
if (_inShutdown) {
break;
}
}
}
}
Lock::GlobalWrite globalWriteLock(opCtx);
lk.lock();
// Exit drain mode only if we're actually in draining mode, the apply buffer is empty in the
// current term, and we're allowed to become the write master.
if (_applierState != ApplierState::Draining ||
!_topCoord->canCompleteTransitionToPrimary(termWhenBufferIsEmpty)) {