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
|
/**
* Copyright (C) 2013 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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::kCommand
#include "mongo/platform/basic.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/catalog/database.h"
#include "mongo/db/catalog/health_log.h"
#include "mongo/db/catalog/uuid_catalog.h"
#include "mongo/db/commands.h"
#include "mongo/db/concurrency/write_conflict_exception.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/dbcheck.h"
#include "mongo/db/repl/oplog.h"
#include "mongo/db/repl/optime.h"
#include "mongo/util/background.h"
#include "mongo/util/log.h"
namespace mongo {
namespace {
constexpr uint64_t kBatchDocs = 5'000;
constexpr uint64_t kBatchBytes = 20'000'000;
/**
* All the information needed to run dbCheck on a single collection.
*/
struct DbCheckCollectionInfo {
NamespaceString nss;
BSONKey start;
BSONKey end;
int64_t maxCount;
int64_t maxSize;
int64_t maxRate;
};
/**
* A run of dbCheck consists of a series of collections.
*/
using DbCheckRun = std::vector<DbCheckCollectionInfo>;
/**
* Check if dbCheck can run on the given namespace.
*/
bool canRunDbCheckOn(const NamespaceString& nss) {
if (nss.isLocal()) {
return false;
}
// TODO: SERVER-30826.
const std::set<StringData> replicatedSystemCollections{"system.backup_users",
"system.js",
"system.new_users",
"system.roles",
"system.users",
"system.version",
"system.views"};
if (nss.isSystem()) {
if (replicatedSystemCollections.count(nss.coll()) == 0) {
return false;
}
}
return true;
}
std::unique_ptr<DbCheckRun> singleCollectionRun(OperationContext* opCtx,
const std::string& dbName,
const DbCheckSingleInvocation& invocation) {
NamespaceString nss(dbName, invocation.getColl());
AutoGetCollectionForRead agc(opCtx, nss);
uassert(ErrorCodes::NamespaceNotFound,
"Collection " + invocation.getColl() + " not found",
agc.getCollection());
uassert(40619,
"Cannot run dbCheck on " + nss.toString() + " because it is not replicated",
canRunDbCheckOn(nss));
auto start = invocation.getMinKey();
auto end = invocation.getMaxKey();
auto maxCount = invocation.getMaxCount();
auto maxSize = invocation.getMaxSize();
auto maxRate = invocation.getMaxCountPerSecond();
auto info = DbCheckCollectionInfo{nss, start, end, maxCount, maxSize, maxRate};
auto result = stdx::make_unique<DbCheckRun>();
result->push_back(info);
return result;
}
std::unique_ptr<DbCheckRun> fullDatabaseRun(OperationContext* opCtx,
const std::string& dbName,
const DbCheckAllInvocation& invocation) {
uassert(
ErrorCodes::InvalidNamespace, "Cannot run dbCheck on local database", dbName != "local");
// Read the list of collections in a database-level lock.
AutoGetDb agd(opCtx, StringData(dbName), MODE_S);
auto db = agd.getDb();
auto result = stdx::make_unique<DbCheckRun>();
uassert(ErrorCodes::NamespaceNotFound, "Database " + dbName + " not found", agd.getDb());
int64_t max = std::numeric_limits<int64_t>::max();
auto rate = invocation.getMaxCountPerSecond();
for (Collection* coll : *db) {
DbCheckCollectionInfo info{coll->ns(), BSONKey::min(), BSONKey::max(), max, max, rate};
result->push_back(info);
}
return result;
}
/**
* Factory function for producing DbCheckRun's from command objects.
*/
std::unique_ptr<DbCheckRun> getRun(OperationContext* opCtx,
const std::string& dbName,
const BSONObj& obj) {
BSONObjBuilder builder;
// Get rid of generic command fields.
for (const auto& elem : obj) {
if (!Command::isGenericArgument(elem.fieldNameStringData())) {
builder.append(elem);
}
}
BSONObj toParse = builder.obj();
// If the dbCheck argument is a string, this is the per-collection form.
if (toParse["dbCheck"].type() == BSONType::String) {
return singleCollectionRun(
opCtx, dbName, DbCheckSingleInvocation::parse(IDLParserErrorContext(""), toParse));
} else {
// Otherwise, it's the database-wide form.
return fullDatabaseRun(
opCtx, dbName, DbCheckAllInvocation::parse(IDLParserErrorContext(""), toParse));
}
}
/**
* The BackgroundJob in which dbCheck actually executes on the primary.
*/
class DbCheckJob : public BackgroundJob {
public:
DbCheckJob(const StringData& dbName, std::unique_ptr<DbCheckRun> run)
: BackgroundJob(true), _done(false), _dbName(dbName.toString()), _run(std::move(run)) {}
protected:
virtual std::string name() const override {
return "dbCheck";
}
virtual void run() override {
// Every dbCheck runs in its own client.
Client::initThread(name());
for (const auto& coll : *_run) {
try {
_doCollection(coll);
} catch (const DBException& e) {
auto logEntry = dbCheckErrorHealthLogEntry(
coll.nss, "dbCheck failed", OplogEntriesEnum::Batch, e.toStatus());
HealthLog::get(Client::getCurrent()->getServiceContext()).log(*logEntry);
return;
}
if (_done) {
log() << "dbCheck terminated due to stepdown";
return;
}
}
}
private:
void _doCollection(const DbCheckCollectionInfo& info) {
// If we can't find the collection, abort the check.
if (!_getCollectionMetadata(info)) {
return;
}
if (_done) {
return;
}
// Parameters for the hasher.
auto start = info.start;
bool reachedEnd = false;
// Make sure the totals over all of our batches don't exceed the provided limits.
int64_t totalBytesSeen = 0;
int64_t totalDocsSeen = 0;
// Limit the rate of the check.
using Clock = stdx::chrono::system_clock;
using TimePoint = stdx::chrono::time_point<Clock>;
TimePoint lastStart = Clock::now();
int64_t docsInCurrentInterval = 0;
do {
using namespace std::literals::chrono_literals;
if (Clock::now() - lastStart > 1s) {
lastStart = Clock::now();
docsInCurrentInterval = 0;
}
auto result = _runBatch(info, start, kBatchDocs, kBatchBytes);
if (_done) {
return;
}
std::unique_ptr<HealthLogEntry> entry;
if (!result.isOK()) {
entry = dbCheckErrorHealthLogEntry(
info.nss, "dbCheck batch failed", OplogEntriesEnum::Batch, result.getStatus());
HealthLog::get(Client::getCurrent()->getServiceContext()).log(*entry);
return;
} else {
auto stats = result.getValue();
entry = dbCheckBatchEntry(info.nss,
stats.nDocs,
stats.nBytes,
stats.md5,
stats.md5,
start,
stats.lastKey,
stats.time);
HealthLog::get(Client::getCurrent()->getServiceContext()).log(*entry);
}
auto stats = result.getValue();
start = stats.lastKey;
// Update our running totals.
totalDocsSeen += stats.nDocs;
totalBytesSeen += stats.nBytes;
docsInCurrentInterval += stats.nDocs;
// Check if we've exceeded any limits.
bool reachedLast = stats.lastKey >= info.end;
bool tooManyDocs = totalDocsSeen >= info.maxCount;
bool tooManyBytes = totalBytesSeen >= info.maxSize;
reachedEnd = reachedLast || tooManyDocs || tooManyBytes;
if (docsInCurrentInterval > info.maxRate && info.maxRate > 0) {
// If an extremely low max rate has been set (substantially smaller than the batch
// size) we might want to sleep for multiple seconds between batches.
int64_t timesExceeded = docsInCurrentInterval / info.maxRate;
stdx::this_thread::sleep_for(timesExceeded * 1s - (Clock::now() - lastStart));
}
} while (!reachedEnd);
}
/**
* For organizing the results of batches.
*/
struct BatchStats {
int64_t nDocs;
int64_t nBytes;
BSONKey lastKey;
std::string md5;
repl::OpTime time;
};
// Set if the job cannot proceed.
bool _done;
std::string _dbName;
std::unique_ptr<DbCheckRun> _run;
bool _getCollectionMetadata(const DbCheckCollectionInfo& info) {
auto uniqueOpCtx = Client::getCurrent()->makeOperationContext();
auto opCtx = uniqueOpCtx.get();
// While we get the prev/next UUID information, we need a database-level lock, plus a global
// IX lock (see SERVER-28544).
AutoGetDbForDbCheck agd(opCtx, info.nss);
if (_stepdownHasOccurred(opCtx, info.nss)) {
_done = true;
return true;
}
auto db = agd.getDb();
if (!db) {
return false;
}
auto collection = db->getCollection(opCtx, info.nss);
if (!collection) {
return false;
}
auto uuid = collection->uuid();
// Check if UUID exists.
if (!uuid) {
return false;
}
auto prev = UUIDCatalog::get(opCtx).prev(_dbName, *uuid);
auto next = UUIDCatalog::get(opCtx).next(_dbName, *uuid);
// Find and report collection metadata.
auto indices = collectionIndexInfo(opCtx, collection);
auto options = collectionOptions(opCtx, collection);
DbCheckOplogCollection entry;
entry.setNss(collection->ns());
entry.setUuid(*collection->uuid());
if (prev) {
entry.setPrev(*prev);
}
if (next) {
entry.setNext(*next);
}
entry.setType(OplogEntriesEnum::Collection);
entry.setIndexes(indices);
entry.setOptions(options);
// Send information on this collection over the oplog for the secondary to check.
auto optime = _logOp(opCtx, collection->ns(), collection->uuid(), entry.toBSON());
DbCheckCollectionInformation collectionInfo;
collectionInfo.collectionName = collection->ns().coll().toString();
collectionInfo.prev = entry.getPrev();
collectionInfo.next = entry.getNext();
collectionInfo.indexes = entry.getIndexes();
collectionInfo.options = entry.getOptions();
auto hle = dbCheckCollectionEntry(
collection->ns(), *collection->uuid(), collectionInfo, collectionInfo, optime);
HealthLog::get(opCtx).log(*hle);
return true;
}
StatusWith<BatchStats> _runBatch(const DbCheckCollectionInfo& info,
const BSONKey& first,
int64_t batchDocs,
int64_t batchBytes) {
// New OperationContext for each batch.
auto uniqueOpCtx = Client::getCurrent()->makeOperationContext();
auto opCtx = uniqueOpCtx.get();
DbCheckOplogBatch batch;
// Find the relevant collection.
AutoGetCollectionForDbCheck agc(opCtx, info.nss, OplogEntriesEnum::Batch);
if (_stepdownHasOccurred(opCtx, info.nss)) {
_done = true;
return Status(ErrorCodes::PrimarySteppedDown, "dbCheck terminated due to stepdown");
}
auto collection = agc.getCollection();
if (!collection) {
return {ErrorCodes::NamespaceNotFound, "dbCheck collection no longer exists"};
}
boost::optional<DbCheckHasher> hasher;
try {
hasher.emplace(opCtx,
collection,
first,
info.end,
std::min(batchDocs, info.maxCount),
std::min(batchBytes, info.maxSize));
} catch (const DBException& e) {
return e.toStatus();
}
Status status = hasher->hashAll();
if (!status.isOK()) {
return status;
}
std::string md5 = hasher->total();
batch.setType(OplogEntriesEnum::Batch);
batch.setNss(info.nss);
batch.setMd5(md5);
batch.setMinKey(first);
batch.setMaxKey(BSONKey(hasher->lastKey()));
BatchStats result;
// Send information on this batch over the oplog.
result.time = _logOp(opCtx, info.nss, collection->uuid(), batch.toBSON());
result.nDocs = hasher->docsSeen();
result.nBytes = hasher->bytesSeen();
result.lastKey = hasher->lastKey();
result.md5 = md5;
return result;
}
/**
* Return `true` iff the primary the check is running on has stepped down.
*/
bool _stepdownHasOccurred(OperationContext* opCtx, const NamespaceString& nss) {
Status status = opCtx->checkForInterruptNoAssert();
if (!status.isOK()) {
return true;
}
auto coord = repl::ReplicationCoordinator::get(opCtx);
if (!coord->canAcceptWritesFor(opCtx, nss)) {
return true;
}
return false;
}
repl::OpTime _logOp(OperationContext* opCtx,
const NamespaceString& nss,
OptionalCollectionUUID uuid,
const BSONObj& obj) {
return writeConflictRetry(
opCtx, "dbCheck oplog entry", NamespaceString::kRsOplogNamespace.ns(), [&] {
auto const clockSource = opCtx->getServiceContext()->getFastClockSource();
const auto wallClockTime = clockSource->now();
WriteUnitOfWork uow(opCtx);
repl::OpTime result = repl::logOp(opCtx,
"c",
nss,
uuid,
obj,
nullptr,
false,
wallClockTime,
{},
kUninitializedStmtId,
{});
uow.commit();
return result;
});
}
};
/**
* The command, as run on the primary.
*/
class DbCheckCmd : public BasicCommand {
public:
DbCheckCmd() : BasicCommand("dbCheck") {}
virtual bool slaveOk() const {
return false;
}
virtual bool adminOnly() const {
return false;
}
virtual bool supportsWriteConcern(const BSONObj& cmd) const override {
return false;
}
virtual void help(std::stringstream& help) const {
help << "Validate replica set consistency.\n"
<< "Invoke with { dbCheck: <collection name/uuid>,\n"
<< " minKey: <first key, exclusive>,\n"
<< " maxKey: <last key, inclusive>,\n"
<< " maxCount: <max number of docs>,\n"
<< " maxSize: <max size of docs>,\n"
<< " maxCountPerSecond: <max rate in docs/sec> } "
<< "to check a collection.\n"
<< "Invoke with {dbCheck: 1} to check all collections in the database.";
}
virtual Status checkAuthForCommand(Client* client,
const std::string& dbname,
const BSONObj& cmdObj) {
// For now, just use `find` permissions.
const NamespaceString nss(parseNs(dbname, cmdObj));
// First, check that we can read this collection.
Status status = AuthorizationSession::get(client)->checkAuthForFind(nss, false);
if (!status.isOK()) {
return status;
}
// Then check that we can read the health log.
return AuthorizationSession::get(client)->checkAuthForFind(HealthLog::nss, false);
}
virtual bool run(OperationContext* opCtx,
const std::string& dbname,
const BSONObj& cmdObj,
BSONObjBuilder& result) {
uassert(40614, "dbCheck requires FeatureCompatibilityVersion >= 3.6", _hasCorrectFCV());
auto job = getRun(opCtx, dbname, cmdObj);
try {
(new DbCheckJob(dbname, std::move(job)))->go();
} catch (const DBException& e) {
result.append("ok", false);
result.append("err", e.toString());
return false;
}
result.append("ok", true);
return true;
}
private:
bool _hasCorrectFCV(void) {
return serverGlobalParams.featureCompatibility.getVersion() ==
ServerGlobalParams::FeatureCompatibility::Version::kFullyUpgradedTo36;
}
};
MONGO_INITIALIZER(RegisterDbCheckCmd)(InitializerContext* context) {
if (Command::testCommandsEnabled) {
new DbCheckCmd();
}
return Status::OK();
}
} // namespace
}
|