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
|
/**
* 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_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kDefault
#include "mongo/platform/basic.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/catalog/coll_mod.h"
#include "mongo/db/catalog/database.h"
#include "mongo/db/catalog/database_holder.h"
#include "mongo/db/catalog/drop_indexes.h"
#include "mongo/db/catalog/index_catalog.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/feature_compatibility_version.h"
#include "mongo/db/commands/feature_compatibility_version_documentation.h"
#include "mongo/db/commands/feature_compatibility_version_parser.h"
#include "mongo/db/commands/set_feature_compatibility_version_gen.h"
#include "mongo/db/concurrency/d_concurrency.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/dbdirectclient.h"
#include "mongo/db/index_builds_coordinator.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/ops/write_ops.h"
#include "mongo/db/read_write_concern_defaults.h"
#include "mongo/db/repl/repl_client_info.h"
#include "mongo/db/repl/repl_server_parameters_gen.h"
#include "mongo/db/repl/repl_set_config.h"
#include "mongo/db/repl/replication_coordinator.h"
#include "mongo/db/s/config/sharding_catalog_manager.h"
#include "mongo/db/server_options.h"
#include "mongo/db/transaction_history_iterator.h"
#include "mongo/db/views/view_catalog.h"
#include "mongo/logv2/log.h"
#include "mongo/rpc/get_status_from_command_result.h"
#include "mongo/s/write_ops/batched_command_response.h"
#include "mongo/stdx/unordered_set.h"
#include "mongo/util/exit.h"
#include "mongo/util/fail_point.h"
#include "mongo/util/scopeguard.h"
namespace mongo {
namespace {
using FCVP = FeatureCompatibilityVersionParser;
using FeatureCompatibility = ServerGlobalParams::FeatureCompatibility;
MONGO_FAIL_POINT_DEFINE(failUpgrading);
MONGO_FAIL_POINT_DEFINE(hangWhileUpgrading);
MONGO_FAIL_POINT_DEFINE(hangAfterStartingFCVTransition);
MONGO_FAIL_POINT_DEFINE(failDowngrading);
MONGO_FAIL_POINT_DEFINE(hangWhileDowngrading);
/**
* Ensures that only one instance of setFeatureCompatibilityVersion can run at a given time.
*/
Lock::ResourceMutex commandMutex("setFCVCommandMutex");
/**
* Deletes the persisted default read/write concern document.
*/
void deletePersistedDefaultRWConcernDocument(OperationContext* opCtx) {
DBDirectClient client(opCtx);
const auto commandResponse = client.runCommand([&] {
write_ops::DeleteCommandRequest deleteOp(NamespaceString::kConfigSettingsNamespace);
deleteOp.setDeletes({[&] {
write_ops::DeleteOpEntry entry;
entry.setQ(BSON("_id" << ReadWriteConcernDefaults::kPersistedDocumentId));
entry.setMulti(false);
return entry;
}()});
return deleteOp.serialize({});
}());
uassertStatusOK(getStatusFromWriteCommandReply(commandResponse->getCommandReply()));
}
void checkInitialSyncFinished(OperationContext* opCtx) {
auto replCoord = repl::ReplicationCoordinator::get(opCtx);
const bool isReplSet =
replCoord->getReplicationMode() == repl::ReplicationCoordinator::modeReplSet;
uassert(ErrorCodes::ConflictingOperationInProgress,
str::stream() << "Cannot upgrade/downgrade the cluster when the replica set config "
<< "contains 'newlyAdded' members; wait for those members to "
<< "finish its initial sync procedure",
!(isReplSet && replCoord->replSetContainsNewlyAddedMembers()));
// We should make sure the current config w/o 'newlyAdded' members got replicated
// to all nodes.
LOGV2(4637904, "Waiting for the current replica set config to propagate to all nodes.");
// If a write concern is given, we'll use its wTimeout. It's kNoTimeout by default.
WriteConcernOptions writeConcern(repl::ReplSetConfig::kConfigAllWriteConcernName,
WriteConcernOptions::SyncMode::NONE,
opCtx->getWriteConcern().wTimeout);
writeConcern.checkCondition = WriteConcernOptions::CheckCondition::Config;
repl::OpTime fakeOpTime(Timestamp(1, 1), replCoord->getTerm());
uassertStatusOKWithContext(
replCoord->awaitReplication(opCtx, fakeOpTime, writeConcern).status,
"Failed to wait for the current replica set config to propagate to all nodes");
LOGV2(4637905, "The current replica set config has been propagated to all nodes.");
}
void waitForCurrentConfigCommitment(OperationContext* opCtx) {
auto replCoord = repl::ReplicationCoordinator::get(opCtx);
// Skip the waiting if the current config is from a force reconfig.
auto oplogWait = replCoord->getConfig().getConfigTerm() != repl::OpTime::kUninitializedTerm;
auto status = replCoord->awaitConfigCommitment(opCtx, oplogWait);
status.addContext("New feature compatibility version is rejected");
if (status == ErrorCodes::MaxTimeMSExpired) {
// Convert the error code to be more specific.
uasserted(ErrorCodes::CurrentConfigNotCommittedYet, status.reason());
}
uassertStatusOK(status);
}
void removeTimeseriesEntriesFromConfigTransactions(OperationContext* opCtx,
const std::vector<LogicalSessionId>& sessions) {
DBDirectClient dbClient(opCtx);
for (const auto& session : sessions) {
dbClient.remove(NamespaceString::kSessionTransactionsTableNamespace.ns(),
QUERY(LogicalSessionRecord::kIdFieldName << session.toBSON()));
}
}
void removeTimeseriesEntriesFromConfigTransactions(OperationContext* opCtx) {
DBDirectClient dbClient(opCtx);
std::vector<LogicalSessionId> sessions;
static constexpr StringData kLastWriteOpFieldName = "lastWriteOpTime"_sd;
auto cursor = dbClient.query(NamespaceString::kSessionTransactionsTableNamespace, Query{});
while (cursor->more()) {
auto entry = TransactionHistoryIterator{repl::OpTime::parse(
cursor->next()[kLastWriteOpFieldName].Obj())}
.next(opCtx);
if (entry.getNss().isTimeseriesBucketsCollection()) {
sessions.push_back(*entry.getSessionId());
}
}
if (sessions.empty()) {
return;
}
auto replCoord = repl::ReplicationCoordinator::get(opCtx);
if (replCoord->getReplicationMode() == repl::ReplicationCoordinator::modeReplSet &&
opCtx->getLogicalSessionId()) {
// Perform the deletes using a separate client because direct writes to config.transactions
// are not allowed in sessions.
auto client =
getGlobalServiceContext()->makeClient("removeTimeseriesEntriesFromConfigTransactions");
AlternativeClientRegion acr(client);
removeTimeseriesEntriesFromConfigTransactions(cc().makeOperationContext().get(), sessions);
} else {
removeTimeseriesEntriesFromConfigTransactions(opCtx, sessions);
}
}
/**
* Sets the minimum allowed feature compatibility version for the cluster. The cluster should not
* use any new features introduced in binary versions that are newer than the feature compatibility
* version set.
*
* Format:
* {
* setFeatureCompatibilityVersion: <string version>
* }
*/
class SetFeatureCompatibilityVersionCommand : public BasicCommand {
public:
SetFeatureCompatibilityVersionCommand()
: BasicCommand(SetFeatureCompatibilityVersion::kCommandName) {}
AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
return AllowedOnSecondary::kNever;
}
bool adminOnly() const override {
return true;
}
bool supportsWriteConcern(const BSONObj& cmd) const override {
return true;
}
std::string help() const override {
std::stringstream h;
h << "Set the featureCompatibilityVersion used by this cluster. If set to '"
<< FCVP::kLastLTS << "', then features introduced in versions greater than '"
<< FCVP::kLastLTS << "' will be disabled";
if (FCVP::kLastContinuous != FCVP::kLastLTS) {
h << " If set to '" << FCVP::kLastContinuous << "', then features introduced in '"
<< FCVP::kLatest << "' will be disabled.";
}
h << " If set to '" << FCVP::kLatest << "', then '" << FCVP::kLatest
<< "' features are enabled, and all nodes in the cluster must be binary version "
<< FCVP::kLatest << ". See "
<< feature_compatibility_version_documentation::kCompatibilityLink << ".";
return h.str();
}
Status checkAuthForCommand(Client* client,
const std::string& dbname,
const BSONObj& cmdObj) const override {
if (!AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
ResourcePattern::forClusterResource(),
ActionType::setFeatureCompatibilityVersion)) {
return Status(ErrorCodes::Unauthorized, "Unauthorized");
}
return Status::OK();
}
bool run(OperationContext* opCtx,
const std::string& dbname,
const BSONObj& cmdObj,
BSONObjBuilder& result) override {
// Always wait for at least majority writeConcern to ensure all writes involved in the
// upgrade process cannot be rolled back. There is currently no mechanism to specify a
// default writeConcern, so we manually call waitForWriteConcern upon exiting this command.
//
// TODO SERVER-25778: replace this with the general mechanism for specifying a default
// writeConcern.
ON_BLOCK_EXIT([&] {
// Propagate the user's wTimeout if one was given.
auto timeout =
opCtx->getWriteConcern().usedDefault ? INT_MAX : opCtx->getWriteConcern().wTimeout;
WriteConcernResult res;
auto waitForWCStatus = waitForWriteConcern(
opCtx,
repl::ReplClientInfo::forClient(opCtx->getClient()).getLastOp(),
WriteConcernOptions(repl::ReplSetConfig::kMajorityWriteConcernModeName,
WriteConcernOptions::SyncMode::UNSET,
timeout),
&res);
CommandHelpers::appendCommandWCStatus(result, waitForWCStatus, res);
});
// Ensure that this operation will be killed by the RstlKillOpThread during step-up or
// stepdown.
opCtx->setAlwaysInterruptAtStepDownOrUp();
// Only allow one instance of setFeatureCompatibilityVersion to run at a time.
Lock::ExclusiveLock setFCVCommandLock(opCtx->lockState(), commandMutex);
auto request = SetFeatureCompatibilityVersion::parse(
IDLParserErrorContext("setFeatureCompatibilityVersion"), cmdObj);
const auto requestedVersion = request.getCommandParameter();
const auto actualVersion = serverGlobalParams.featureCompatibility.getVersion();
if (request.getDowngradeOnDiskChanges()) {
uassert(
ErrorCodes::IllegalOperation,
str::stream() << "Cannot set featureCompatibilityVersion to "
<< FCVP::serializeVersion(requestedVersion) << " with '"
<< SetFeatureCompatibilityVersion::kDowngradeOnDiskChangesFieldName
<< "' set to true. This is only allowed when downgrading to "
<< FCVP::kLastContinuous,
requestedVersion <= actualVersion &&
requestedVersion == FeatureCompatibility::kLastContinuous);
}
if (requestedVersion == actualVersion) {
// Set the client's last opTime to the system last opTime so no-ops wait for
// writeConcern.
repl::ReplClientInfo::forClient(opCtx->getClient()).setLastOpToSystemLastOpTime(opCtx);
return true;
}
auto isFromConfigServer = request.getFromConfigServer().value_or(false);
FeatureCompatibilityVersion::validateSetFeatureCompatibilityVersionRequest(
actualVersion, requestedVersion, isFromConfigServer);
uassert(5563600,
"'phase' field is only valid to be specified on shards",
!request.getPhase() || serverGlobalParams.clusterRole == ClusterRole::ShardServer);
if (!request.getPhase() || request.getPhase() == SetFCVPhaseEnum::kStart) {
{
// Start transition to 'requestedVersion' by updating the local FCV document to a
// 'kUpgrading' or 'kDowngrading' state, respectively.
const auto fcvChangeRegion(
FeatureCompatibilityVersion::enterFCVChangeRegion(opCtx));
checkInitialSyncFinished(opCtx);
FeatureCompatibilityVersion::updateFeatureCompatibilityVersionDocument(
opCtx,
actualVersion,
requestedVersion,
isFromConfigServer,
true /* setTargetVersion */);
}
if (request.getPhase() == SetFCVPhaseEnum::kStart) {
invariant(serverGlobalParams.clusterRole == ClusterRole::ShardServer);
if (actualVersion > requestedVersion) {
// Downgrading
// TODO SERVER-55898: Release fcvChangeRegion and wait for DDLCoordinators to
// drain
}
// If we are only running phase-1, then we are done
return true;
}
}
invariant(!request.getPhase() || request.getPhase() == SetFCVPhaseEnum::kComplete);
uassert(5563601,
"Cannot transition to fully upgraded or fully downgraded state if we are not in "
"kUpgrading or kDowngrading state",
serverGlobalParams.featureCompatibility.isUpgradingOrDowngrading());
hangAfterStartingFCVTransition.pauseWhileSet(opCtx);
if (requestedVersion > actualVersion) {
_runUpgrade(opCtx, request);
} else {
_runDowngrade(opCtx, request);
}
{
// Complete transition by updating the local FCV document to the fully upgraded or
// downgraded requestedVersion.
const auto fcvChangeRegion(FeatureCompatibilityVersion::enterFCVChangeRegion(opCtx));
FeatureCompatibilityVersion::updateFeatureCompatibilityVersionDocument(
opCtx,
serverGlobalParams.featureCompatibility.getVersion(),
requestedVersion,
isFromConfigServer,
false /* setTargetVersion */);
}
return true;
}
private:
void _runUpgrade(OperationContext* opCtx, const SetFeatureCompatibilityVersion& request) {
const auto requestedVersion = request.getCommandParameter();
if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
// Tell the shards to enter phase-1 of setFCV
auto requestPhase1 = request;
requestPhase1.setPhase(SetFCVPhaseEnum::kStart);
uassertStatusOK(
ShardingCatalogManager::get(opCtx)->setFeatureCompatibilityVersionOnShards(
opCtx, CommandHelpers::appendMajorityWriteConcern(requestPhase1.toBSON({}))));
}
auto replCoord = repl::ReplicationCoordinator::get(opCtx);
const bool isReplSet =
replCoord->getReplicationMode() == repl::ReplicationCoordinator::modeReplSet;
// If the 'useSecondaryDelaySecs' feature flag is enabled in the upgraded FCV, issue a
// reconfig to change the 'slaveDelay' field to 'secondaryDelaySecs'.
if (repl::feature_flags::gUseSecondaryDelaySecs.isEnabledAndIgnoreFCV() && isReplSet &&
requestedVersion >= repl::feature_flags::gUseSecondaryDelaySecs.getVersion()) {
// Wait for the current config to be committed before starting a new reconfig.
waitForCurrentConfigCommitment(opCtx);
auto getNewConfig = [&](const repl::ReplSetConfig& oldConfig, long long term) {
auto newConfig = oldConfig.getMutable();
newConfig.setConfigVersion(newConfig.getConfigVersion() + 1);
for (auto mem = oldConfig.membersBegin(); mem != oldConfig.membersEnd(); mem++) {
newConfig.useSecondaryDelaySecsFieldName(mem->getId());
}
return repl::ReplSetConfig(std::move(newConfig));
};
auto status = replCoord->doReplSetReconfig(opCtx, getNewConfig, false /* force */);
uassertStatusOKWithContext(status, "Failed to upgrade the replica set config");
uassertStatusOKWithContext(
replCoord->awaitConfigCommitment(opCtx, true /* waitForOplogCommitment */),
"The upgraded replica set config failed to propagate to a majority");
LOGV2(5042302, "The upgraded replica set config has been propagated to a majority");
}
{
// Take the global lock in S mode to create a barrier for operations taking the global
// IX or X locks. This ensures that either:
// - The global IX/X locked operation will start after the FCV change, see the
// upgrading to the latest FCV and act accordingly.
// - The global IX/X locked operation began prior to the FCV change, is acting on that
// assumption and will finish before upgrade procedures begin right after this.
Lock::GlobalLock lk(opCtx, MODE_S);
}
uassert(ErrorCodes::Error(549180),
"Failing upgrade due to 'failUpgrading' failpoint set",
!failUpgrading.shouldFail());
// Delete any haystack indexes if we're upgrading to an FCV of 4.9 or higher.
//
// TODO SERVER-51871: This block can removed once 5.0 becomes last-lts.
if (requestedVersion >= FeatureCompatibility::Version::kVersion49) {
_deleteHaystackIndexesOnUpgrade(opCtx);
}
if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
// TODO SERVER-53283: This block can removed once 5.0 becomes last-lts.
// TODO SERVER-53774: Replace kLatest by the version defined in the feature flag IDL
if (requestedVersion >= FeatureCompatibility::kLatest) {
ShardingCatalogManager::get(opCtx)->upgradeMetadataFor50Phase1(opCtx);
}
// Tell the shards to enter phase-2 of setFCV (fully upgraded)
auto requestPhase2 = request;
requestPhase2.setPhase(SetFCVPhaseEnum::kComplete);
uassertStatusOK(
ShardingCatalogManager::get(opCtx)->setFeatureCompatibilityVersionOnShards(
opCtx, CommandHelpers::appendMajorityWriteConcern(requestPhase2.toBSON({}))));
// TODO SERVER-53283: This block can removed once 5.0 becomes last-lts.
// TODO SERVER-53774: Replace kLatest by the version defined in the feature flag IDL
if (requestedVersion >= FeatureCompatibility::kLatest) {
ShardingCatalogManager::get(opCtx)->upgradeMetadataFor50Phase2(opCtx);
}
}
hangWhileUpgrading.pauseWhileSet(opCtx);
}
/**
* Removes all haystack indexes from the catalog.
*
* TODO SERVER-51871: This method can be removed once 5.0 becomes last-lts.
*/
void _deleteHaystackIndexesOnUpgrade(OperationContext* opCtx) {
auto collCatalog = CollectionCatalog::get(opCtx);
for (const auto& db : collCatalog->getAllDbNames()) {
for (auto collIt = collCatalog->begin(opCtx, db); collIt != collCatalog->end(opCtx);
++collIt) {
NamespaceStringOrUUID collName(
collCatalog->lookupNSSByUUID(opCtx, collIt.uuid().get()).get());
AutoGetCollectionForRead coll(opCtx, collName);
if (!coll) {
continue;
}
auto idxCatalog = coll->getIndexCatalog();
std::vector<const IndexDescriptor*> haystackIndexes;
idxCatalog->findIndexByType(opCtx, IndexNames::GEO_HAYSTACK, haystackIndexes);
// Continue if 'coll' has no haystack indexes.
if (haystackIndexes.empty()) {
continue;
}
std::vector<std::string> indexNames;
for (auto&& haystackIndex : haystackIndexes) {
indexNames.emplace_back(haystackIndex->indexName());
}
dropIndexes(opCtx, *collName.nss(), indexNames);
}
}
}
void _runDowngrade(OperationContext* opCtx, const SetFeatureCompatibilityVersion& request) {
const auto requestedVersion = request.getCommandParameter();
if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
// Tell the shards to enter phase-1 of setFCV
auto requestPhase1 = request;
requestPhase1.setPhase(SetFCVPhaseEnum::kStart);
uassertStatusOK(
ShardingCatalogManager::get(opCtx)->setFeatureCompatibilityVersionOnShards(
opCtx, CommandHelpers::appendMajorityWriteConcern(requestPhase1.toBSON({}))));
}
auto replCoord = repl::ReplicationCoordinator::get(opCtx);
const bool isReplSet =
replCoord->getReplicationMode() == repl::ReplicationCoordinator::modeReplSet;
// Time-series collections are only supported in 5.0. If the user tries to downgrade the
// cluster to an earlier version, they must first remove all time-series collections.
// TODO (SERVER-56171): Remove once 5.0 is last-lts.
for (const auto& dbName : DatabaseHolder::get(opCtx)->getNames()) {
auto viewCatalog = DatabaseHolder::get(opCtx)->getViewCatalog(opCtx, dbName);
if (!viewCatalog) {
continue;
}
viewCatalog->iterate([](const ViewDefinition& view) {
uassert(ErrorCodes::CannotDowngrade,
str::stream()
<< "Cannot downgrade the cluster when there are time-series "
"collections present; drop all time-series collections before "
"downgrading. First detected time-series collection: "
<< view.name(),
!view.timeseries());
return true;
});
}
// TODO (SERVER-56171): Remove once 5.0 is last-lts.
removeTimeseriesEntriesFromConfigTransactions(opCtx);
// If the 'useSecondaryDelaySecs' feature flag is disabled in the downgraded FCV, issue a
// reconfig to change the 'secondaryDelaySecs' field to 'slaveDelay'.
if (isReplSet && repl::feature_flags::gUseSecondaryDelaySecs.isEnabledAndIgnoreFCV() &&
requestedVersion < repl::feature_flags::gUseSecondaryDelaySecs.getVersion()) {
// Wait for the current config to be committed before starting a new reconfig.
waitForCurrentConfigCommitment(opCtx);
auto getNewConfig = [&](const repl::ReplSetConfig& oldConfig, long long term) {
auto newConfig = oldConfig.getMutable();
newConfig.setConfigVersion(newConfig.getConfigVersion() + 1);
for (auto mem = oldConfig.membersBegin(); mem != oldConfig.membersEnd(); mem++) {
newConfig.useSlaveDelayFieldName(mem->getId());
}
return repl::ReplSetConfig(std::move(newConfig));
};
auto status = replCoord->doReplSetReconfig(opCtx, getNewConfig, false /* force */);
uassertStatusOKWithContext(status, "Failed to downgrade the replica set config");
uassertStatusOKWithContext(
replCoord->awaitConfigCommitment(opCtx, true /* waitForOplogCommitment */),
"The downgraded replica set config failed to propagate to a majority");
LOGV2(5042304, "The downgraded replica set config has been propagated to a majority");
}
{
// Take the global lock in S mode to create a barrier for operations taking the global
// IX or X locks. This ensures that either
// - The global IX/X locked operation will start after the FCV change, see the
// downgrading to the last-lts or last-continuous FCV and act accordingly.
// - The global IX/X locked operation began prior to the FCV change, is acting on that
// assumption and will finish before downgrade procedures begin right after this.
Lock::GlobalLock lk(opCtx, MODE_S);
}
uassert(ErrorCodes::Error(549181),
"Failing upgrade due to 'failDowngrading' failpoint set",
!failDowngrading.shouldFail());
if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
// TODO SERVER-53283: This block can removed once 5.0 becomes last-lts.
// TODO SERVER-53774: Replace kLatest by the version defined in the feature flag IDL
if (requestedVersion < FeatureCompatibility::kLatest) {
ShardingCatalogManager::get(opCtx)->downgradeMetadataToPre50Phase1(opCtx);
}
// Tell the shards to enter phase-2 of setFCV (fully downgraded)
auto requestPhase2 = request;
requestPhase2.setPhase(SetFCVPhaseEnum::kComplete);
uassertStatusOK(
ShardingCatalogManager::get(opCtx)->setFeatureCompatibilityVersionOnShards(
opCtx, CommandHelpers::appendMajorityWriteConcern(requestPhase2.toBSON({}))));
// TODO SERVER-53283: This block can removed once 5.0 becomes last-lts.
// TODO SERVER-53774: Replace kLatest by the version defined in the feature flag IDL
if (requestedVersion < FeatureCompatibility::kLatest) {
ShardingCatalogManager::get(opCtx)->downgradeMetadataToPre50Phase2(opCtx);
}
}
hangWhileDowngrading.pauseWhileSet(opCtx);
if (request.getDowngradeOnDiskChanges()) {
invariant(requestedVersion == FeatureCompatibility::kLastContinuous);
_downgradeOnDiskChanges();
LOGV2(4875603, "Downgrade of on-disk format complete.");
}
}
/**
* Rolls back any upgraded on-disk changes to reflect the disk format of the last-continuous
* version.
*/
void _downgradeOnDiskChanges() {
LOGV2(4975602,
"Downgrading on-disk format to reflect the last-continuous version.",
"last_continuous_version"_attr = FCVP::kLastContinuous);
}
} setFeatureCompatibilityVersionCommand;
} // namespace
} // namespace mongo
|