/
repl.cpp
1712 lines (1549 loc) · 60 KB
/
repl.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
// repl.cpp
/* TODO
PAIRING
_ on a syncexception, don't allow going back to master state?
*/
/**
* Copyright (C) 2008 10gen 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/>.
*/
/* Collections we use:
local.sources - indicates what sources we pull from as a "slave", and the last update of each
local.oplog.$main - our op log as "master"
local.dbinfo.<dbname>
local.pair.startup - can contain a special value indicating for a pair that we have the master copy.
used when replacing other half of the pair which has permanently failed.
local.pair.sync - { initialsynccomplete: 1 }
*/
#include "stdafx.h"
#include "jsobj.h"
#include "../util/goodies.h"
#include "repl.h"
#include "../util/message.h"
#include "../client/dbclient.h"
#include "pdfile.h"
#include "query.h"
#include "db.h"
#include "commands.h"
#include "security.h"
namespace mongo {
extern bool quiet;
extern boost::recursive_mutex &dbMutex;
extern long long oplogSize;
int _updateObjects(const char *ns, BSONObj updateobj, BSONObj pattern, bool upsert, stringstream& ss, bool logOp=false);
void ensureHaveIdIndex(const char *ns);
/* if 1 sync() is running */
int syncing = 0;
/* if true replace our peer in a replication pair -- don't worry about if his
local.oplog.$main is empty.
*/
bool replacePeer = false;
/* "dead" means something really bad happened like replication falling completely out of sync.
when non-null, we are dead and the string is informational
*/
const char *replAllDead = 0;
extern bool autoresync;
time_t lastForcedResync = 0;
IdTracker &idTracker = *( new IdTracker() );
} // namespace mongo
#include "replset.h"
namespace mongo {
PairSync *pairSync = new PairSync();
bool getInitialSyncCompleted() {
return pairSync->initialSyncCompleted();
}
/* --- ReplPair -------------------------------- */
ReplPair *replPair = 0;
/* output by the web console */
const char *replInfo = "";
struct ReplInfo {
ReplInfo(const char *msg) {
replInfo = msg;
}
~ReplInfo() {
replInfo = "?";
}
};
void ReplPair::setMaster(int n, const char *_comment ) {
if ( n == State_Master && !getInitialSyncCompleted() )
return;
info = _comment;
if ( n != state && !quiet )
log() << "pair: setting master=" << n << " was " << state << '\n';
state = n;
}
/* peer unreachable, try our arbiter */
void ReplPair::arbitrate() {
ReplInfo r("arbitrate");
if ( arbHost == "-" ) {
// no arbiter. we are up, let's assume partner is down and network is not partitioned.
setMasterLocked(State_Master, "remote unreachable");
return;
}
auto_ptr<DBClientConnection> conn( newClientConnection() );
string errmsg;
if ( !conn->connect(arbHost.c_str(), errmsg) ) {
log() << "pull: cantconn arbiter " << errmsg << endl;
setMasterLocked(State_CantArb, "can't connect to arb");
return;
}
negotiate( conn.get(), "arbiter" );
}
/* --------------------------------------------- */
class CmdReplacePeer : public Command {
public:
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool logTheOp() {
return false;
}
CmdReplacePeer() : Command("replacepeer") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
if ( replPair == 0 ) {
errmsg = "not paired";
return false;
}
if ( !getInitialSyncCompleted() ) {
errmsg = "not caught up cannot replace peer";
return false;
}
if ( syncing < 0 ) {
errmsg = "replacepeer already invoked";
return false;
}
Timer t;
while ( 1 ) {
if ( syncing == 0 || t.millis() > 20000 )
break;
{
dbtemprelease t;
sleepmillis(10);
}
}
if ( syncing ) {
assert( syncing > 0 );
errmsg = "timeout waiting for sync() to finish";
return false;
}
{
ReplSource::SourceVector sources;
ReplSource::loadAll(sources);
if ( sources.size() != 1 ) {
errmsg = "local.sources.count() != 1, cannot replace peer";
return false;
}
}
{
Helpers::emptyCollection("local.sources");
BSONObj o = fromjson("{\"replacepeer\":1}");
Helpers::putSingleton("local.pair.startup", o);
}
syncing = -1;
replAllDead = "replacepeer invoked -- adjust local.sources hostname then restart this db process";
result.append("info", "adjust local.sources hostname; db restart now required");
return true;
}
} cmdReplacePeer;
class CmdForceDead : public Command {
public:
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool logTheOp() {
return false;
}
CmdForceDead() : Command("forcedead") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
replAllDead = "forced by command";
return true;
}
} cmdForceDead;
class CmdResync : public Command {
public:
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool logTheOp() {
return false;
}
CmdResync() : Command("resync") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
if ( cmdObj.getBoolField( "force" ) ) {
if ( !waitForSyncToFinish( errmsg ) )
return false;
replAllDead = "resync forced";
}
if ( !replAllDead ) {
errmsg = "not dead, no need to resync";
return false;
}
if ( !waitForSyncToFinish( errmsg ) )
return false;
ReplSource::forceResyncDead( "client" );
result.append( "info", "triggered resync for all sources" );
return true;
}
bool waitForSyncToFinish( string &errmsg ) const {
// Wait for slave thread to finish syncing, so sources will be be
// reloaded with new saved state on next pass.
Timer t;
while ( 1 ) {
if ( syncing == 0 || t.millis() > 20000 )
break;
{
dbtemprelease t;
sleepmillis(10);
}
}
if ( syncing ) {
errmsg = "timeout waiting for sync() to finish";
return false;
}
return true;
}
} cmdResync;
class CmdIsMaster : public Command {
public:
virtual bool requiresAuth() { return false; }
virtual bool slaveOk() {
return true;
}
CmdIsMaster() : Command("ismaster") { }
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
/* currently request to arbiter is (somewhat arbitrarily) an ismaster request that is not
authenticated.
we allow unauthenticated ismaster but we aren't as verbose informationally if
one is not authenticated for admin db to be safe.
*/
AuthenticationInfo *ai = authInfo.get();
bool authed = ai == 0 || ai->isAuthorized("admin");
if ( replAllDead ) {
result.append("ismaster", 0.0);
if( authed ) {
if ( replPair )
result.append("remote", replPair->remote);
result.append("info", replAllDead);
}
}
else if ( replPair ) {
result.append("ismaster", replPair->state);
if( authed ) {
result.append("remote", replPair->remote);
if ( !replPair->info.empty() )
result.append("info", replPair->info);
}
}
else {
result.append("ismaster", slave ? 0 : 1);
result.append("msg", "not paired");
}
return true;
}
} cmdismaster;
class CmdIsInitialSyncComplete : public Command {
public:
virtual bool requiresAuth() { return false; }
virtual bool slaveOk() {
return true;
}
CmdIsInitialSyncComplete() : Command( "isinitialsynccomplete" ) {}
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool /*fromRepl*/) {
result.appendBool( "initialsynccomplete", getInitialSyncCompleted() );
return true;
}
} cmdisinitialsynccomplete;
/* negotiate who is master
-1=not set (probably means we just booted)
0=was slave
1=was master
remote,local -> new remote,local
!1,1 -> 0,1
1,!1 -> 1,0
-1,-1 -> dominant->1, nondom->0
0,0 -> dominant->1, nondom->0
1,1 -> dominant->1, nondom->0
{ negotiatemaster:1, i_was:<state>, your_name:<hostname> }
returns:
{ ok:1, you_are:..., i_am:... }
*/
class CmdNegotiateMaster : public Command {
public:
CmdNegotiateMaster() : Command("negotiatemaster") { }
virtual bool slaveOk() {
return true;
}
virtual bool adminOnly() {
return true;
}
virtual bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool) {
if ( replPair == 0 ) {
massert( "Another mongod instance believes incorrectly that this node is its peer", !cmdObj.getBoolField( "fromArbiter" ) );
// assume that we are an arbiter and should forward the request
string host = cmdObj.getStringField("your_name");
int port = cmdObj.getIntField( "your_port" );
if ( port == INT_MIN ) {
errmsg = "no port specified";
problem() << errmsg << endl;
return false;
}
stringstream ss;
ss << host << ":" << port;
string remote = ss.str();
BSONObj ret;
{
dbtemprelease t;
auto_ptr<DBClientConnection> conn( new DBClientConnection() );
if ( !conn->connect( remote.c_str(), errmsg ) ) {
result.append( "you_are", ReplPair::State_Master );
return true;
}
BSONObjBuilder forwardCommand;
forwardCommand.appendElements( cmdObj );
forwardCommand.appendBool( "fromArbiter", true );
ret = conn->findOne( "admin.$cmd", forwardCommand.done() );
}
BSONObjIterator i( ret );
while( i.moreWithEOO() ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
if ( e.fieldName() != string( "ok" ) )
result.append( e );
}
return ( ret.getIntField("ok") == 1 );
}
int was = cmdObj.getIntField("i_was");
string myname = cmdObj.getStringField("your_name");
if ( myname.empty() || was < -3 ) {
errmsg = "your_name/i_was not specified";
return false;
}
int N = ReplPair::State_Negotiating;
int M = ReplPair::State_Master;
int S = ReplPair::State_Slave;
if ( !replPair->dominant( myname ) ) {
result.append( "you_are", N );
result.append( "i_am", replPair->state );
return true;
}
int me, you;
if ( !getInitialSyncCompleted() || ( replPair->state != M && was == M ) ) {
me=S;
you=M;
}
else {
me=M;
you=S;
}
replPair->setMaster( me, "CmdNegotiateMaster::run()" );
result.append("you_are", you);
result.append("i_am", me);
return true;
}
} cmdnegotiatemaster;
int ReplPair::negotiate(DBClientConnection *conn, string method) {
BSONObjBuilder b;
b.append("negotiatemaster",1);
b.append("i_was", state);
b.append("your_name", remoteHost);
b.append("your_port", remotePort);
BSONObj cmd = b.done();
BSONObj res = conn->findOne("admin.$cmd", cmd);
if ( res.getIntField("ok") != 1 ) {
string message = method + " negotiate failed";
problem() << message << ": " << res.toString() << '\n';
setMasterLocked(State_Confused, message.c_str());
return State_Confused;
}
int x = res.getIntField("you_are");
int remote = res.getIntField("i_am");
// State_Negotiating means the remote node is not dominant and cannot
// choose who is master.
if ( x != State_Slave && x != State_Master && x != State_Negotiating ) {
problem() << method << " negotiate: bad you_are value " << res.toString() << endl;
} else if ( x != State_Negotiating ) {
string message = method + " negotiation";
setMasterLocked(x, message.c_str());
}
return remote;
}
struct TestOpTime {
TestOpTime() {
OpTime t;
for ( int i = 0; i < 10; i++ ) {
OpTime s = OpTime::now();
assert( s != t );
t = s;
}
OpTime q = t;
assert( q == t );
assert( !(q != t) );
}
} testoptime;
/* --------------------------------------------------------------*/
ReplSource::ReplSource() {
replacing = false;
nClonedThisPass = 0;
paired = false;
}
ReplSource::ReplSource(BSONObj o) : nClonedThisPass(0) {
replacing = false;
paired = false;
only = o.getStringField("only");
hostName = o.getStringField("host");
_sourceName = o.getStringField("source");
uassert( "'host' field not set in sources collection object", !hostName.empty() );
uassert( "only source='main' allowed for now with replication", sourceName() == "main" );
BSONElement e = o.getField("syncedTo");
if ( !e.eoo() ) {
uassert( "bad sources 'syncedTo' field value", e.type() == Date );
OpTime tmp( e.date() );
syncedTo = tmp;
}
BSONObj dbsObj = o.getObjectField("dbsNextPass");
if ( !dbsObj.isEmpty() ) {
BSONObjIterator i(dbsObj);
while ( 1 ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
addDbNextPass.insert( e.fieldName() );
}
}
dbsObj = o.getObjectField("incompleteCloneDbs");
if ( !dbsObj.isEmpty() ) {
BSONObjIterator i(dbsObj);
while ( 1 ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
incompleteCloneDbs.insert( e.fieldName() );
}
}
lastSavedLocalTs_ = OpTime( o.getField( "localLogTs" ).date() );
}
/* Turn our C++ Source object into a BSONObj */
BSONObj ReplSource::jsobj() {
BSONObjBuilder b;
b.append("host", hostName);
b.append("source", sourceName());
if ( !only.empty() )
b.append("only", only);
if ( !syncedTo.isNull() )
b.appendDate("syncedTo", syncedTo.asDate());
b.appendDate("localLogTs", lastSavedLocalTs_.asDate());
BSONObjBuilder dbsNextPassBuilder;
int n = 0;
for ( set<string>::iterator i = addDbNextPass.begin(); i != addDbNextPass.end(); i++ ) {
n++;
dbsNextPassBuilder.appendBool(i->c_str(), 1);
}
if ( n )
b.append("dbsNextPass", dbsNextPassBuilder.done());
BSONObjBuilder incompleteCloneDbsBuilder;
n = 0;
for ( set<string>::iterator i = incompleteCloneDbs.begin(); i != incompleteCloneDbs.end(); i++ ) {
n++;
incompleteCloneDbsBuilder.appendBool(i->c_str(), 1);
}
if ( n )
b.append("incompleteCloneDbs", incompleteCloneDbsBuilder.done());
return b.obj();
}
void ReplSource::save() {
BSONObjBuilder b;
assert( !hostName.empty() );
b.append("host", hostName);
// todo: finish allowing multiple source configs.
// this line doesn't work right when source is null, if that is allowed as it is now:
//b.append("source", _sourceName);
BSONObj pattern = b.done();
BSONObj o = jsobj();
log( 1 ) << "Saving repl source: " << o << endl;
stringstream ss;
setClient("local.sources");
int u = _updateObjects("local.sources", o, pattern, true/*upsert for pair feature*/, ss);
assert( u == 1 || u == 4 );
database = 0;
if ( replacing ) {
/* if we were in "replace" mode, we now have synced up with the replacement,
so turn that off.
*/
replacing = false;
wassert( replacePeer );
replacePeer = false;
Helpers::emptyCollection("local.pair.startup");
}
}
string dashDashSource;
string dashDashOnly;
static void addSourceToList(ReplSource::SourceVector &v, ReplSource& s, const BSONObj &spec, ReplSource::SourceVector &old) {
if ( !s.syncedTo.isNull() ) { // Don't reuse old ReplSource if there was a forced resync.
for ( ReplSource::SourceVector::iterator i = old.begin(); i != old.end(); ) {
if ( s == **i ) {
v.push_back(*i);
old.erase(i);
return;
}
i++;
}
}
v.push_back( shared_ptr< ReplSource >( new ReplSource( s ) ) );
}
/* we reuse our existing objects so that we can keep our existing connection
and cursor in effect.
*/
void ReplSource::loadAll(SourceVector &v) {
SourceVector old = v;
v.clear();
bool gotPairWith = false;
if ( !dashDashSource.empty() ) {
setClient("local.sources");
// --source <host> specified.
// check that no items are in sources other than that
// add if missing
auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
int n = 0;
while ( c->ok() ) {
n++;
ReplSource tmp(c->current());
if ( tmp.hostName != dashDashSource ) {
log() << "E10000 --source " << dashDashSource << " != " << tmp.hostName << " from local.sources collection" << endl;
log() << "terminating after 30 seconds" << endl;
sleepsecs(30);
dbexit(18);
}
if ( tmp.only != dashDashOnly ) {
log() << "E10001 --only " << dashDashOnly << " != " << tmp.only << " from local.sources collection" << endl;
log() << "terminating after 30 seconds" << endl;
sleepsecs(30);
dbexit(18);
}
c->advance();
}
uassert( "E10002 local.sources collection corrupt?", n<2 );
if ( n == 0 ) {
// source missing. add.
ReplSource s;
s.hostName = dashDashSource;
s.only = dashDashOnly;
s.save();
}
}
else {
try {
massert("--only requires use of --source", dashDashOnly.empty());
} catch ( ... ) {
exit( 40 );
}
}
if ( replPair ) {
const string &remote = replPair->remote;
setClient( "local.sources" );
// --pairwith host specified.
// check that no items are in sources other than that
// add if missing
auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
int n = 0;
while ( c->ok() ) {
n++;
ReplSource tmp(c->current());
if ( tmp.hostName != remote ) {
log() << "E10003 pairwith " << remote << " != " << tmp.hostName << " from local.sources collection" << endl;
log() << "terminating after 30 seconds" << endl;
sleepsecs(30);
dbexit(18);
}
c->advance();
}
uassert( "E10002 local.sources collection corrupt?", n<2 );
if ( n == 0 ) {
// source missing. add.
ReplSource s;
s.hostName = remote;
s.save();
}
}
setClient("local.sources");
auto_ptr<Cursor> c = findTableScan("local.sources", BSONObj());
while ( c->ok() ) {
ReplSource tmp(c->current());
if ( replPair && tmp.hostName == replPair->remote && tmp.sourceName() == "main" ) {
gotPairWith = true;
tmp.paired = true;
if ( replacePeer ) {
// peer was replaced -- start back at the beginning.
tmp.syncedTo = OpTime();
tmp.replacing = true;
}
}
addSourceToList(v, tmp, c->current(), old);
c->advance();
}
database = 0;
if ( !gotPairWith && replPair ) {
/* add the --pairwith server */
shared_ptr< ReplSource > s( new ReplSource() );
s->paired = true;
s->hostName = replPair->remote;
s->replacing = replacePeer;
v.push_back(s);
}
}
BSONObj opTimeQuery = fromjson("{\"getoptime\":1}");
bool ReplSource::throttledForceResyncDead( const char *requester ) {
if ( time( 0 ) - lastForcedResync > 600 ) {
forceResyncDead( requester );
lastForcedResync = time( 0 );
return true;
}
return false;
}
void ReplSource::forceResyncDead( const char *requester ) {
if ( !replAllDead )
return;
SourceVector sources;
ReplSource::loadAll(sources);
for( SourceVector::iterator i = sources.begin(); i != sources.end(); ++i ) {
(*i)->forceResync( requester );
}
replAllDead = 0;
}
void ReplSource::forceResync( const char *requester ) {
BSONObj info;
{
dbtemprelease t;
connect();
bool ok = conn->runCommand( "admin", BSON( "listDatabases" << 1 ), info );
massert( "Unable to get database list", ok );
}
BSONObjIterator i( info.getField( "databases" ).embeddedObject() );
while( i.moreWithEOO() ) {
BSONElement e = i.next();
if ( e.eoo() )
break;
string name = e.embeddedObject().getField( "name" ).valuestr();
if ( !e.embeddedObject().getBoolField( "empty" ) ) {
if ( name != "local" ) {
if ( only.empty() || only == name ) {
resyncDrop( name.c_str(), requester );
}
}
}
}
syncedTo = OpTime();
addDbNextPass.clear();
save();
}
string ReplSource::resyncDrop( const char *db, const char *requester ) {
log() << "resync: dropping database " << db << endl;
string dummyns = string( db ) + ".";
setClientTempNs(dummyns.c_str());
assert( database->name == db );
dropDatabase(dummyns.c_str());
return dummyns;
}
bool ReplSource::resync(string db) {
string dummyNs = resyncDrop( db.c_str(), "internal" );
setClientTempNs( dummyNs.c_str() );
{
log() << "resync: cloning database " << db << endl;
ReplInfo r("resync: cloning a database");
string errmsg;
bool ok = cloneFrom(hostName.c_str(), errmsg, database->name, false, /*slaveok*/ true, /*replauth*/ true);
if ( !ok ) {
problem() << "resync of " << db << " from " << hostName << " failed " << errmsg << endl;
throw SyncException();
}
}
log() << "resync: done " << db << endl;
return true;
}
void ReplSource::applyOperation(const BSONObj& op) {
stringstream ss;
BSONObj o = op.getObjectField("o");
const char *ns = op.getStringField("ns");
// operation type -- see logOp() comments for types
const char *opType = op.getStringField("op");
try {
if ( *opType == 'i' ) {
const char *p = strchr(ns, '.');
if ( p && strcmp(p, ".system.indexes") == 0 ) {
// updates aren't allowed for indexes -- so we will do a regular insert. if index already
// exists, that is ok.
theDataFileMgr.insert(ns, (void*) o.objdata(), o.objsize());
}
else {
// do upserts for inserts as we might get replayed more than once
BSONElement _id;
if( !o.getObjectID(_id) ) {
/* No _id. This will be very slow. */
Timer t;
_updateObjects(ns, o, o, true, ss);
if( t.millis() >= 2 ) {
RARELY OCCASIONALLY log() << "warning, repl doing slow updates (no _id field) for " << ns << endl;
}
}
else {
BSONObjBuilder b;
b.append(_id);
RARELY ensureHaveIdIndex(ns); // otherwise updates will be slow
_updateObjects(ns, o, b.done(), true, ss);
}
}
}
else if ( *opType == 'u' ) {
RARELY ensureHaveIdIndex(ns); // otherwise updates will be super slow
_updateObjects(ns, o, op.getObjectField("o2"), op.getBoolField("b"), ss);
}
else if ( *opType == 'd' ) {
if ( opType[1] == 0 )
deleteObjects(ns, o, op.getBoolField("b"));
else
assert( opType[1] == 'b' ); // "db" advertisement
}
else if ( *opType == 'n' ) {
// no op
}
else {
BufBuilder bb;
BSONObjBuilder ob;
assert( *opType == 'c' );
_runCommands(ns, o, ss, bb, ob, true, 0);
}
}
catch ( UserException& e ) {
log() << "sync: caught user assertion " << e << " while applying op: " << op << endl;;
}
catch ( DBException& e ) {
log() << "sync: caught db exception " << e << " while applying op: " << op << endl;;
}
}
/* local.$oplog.main is of the form:
{ ts: ..., op: <optype>, ns: ..., o: <obj> , o2: <extraobj>, b: <boolflag> }
...
see logOp() comments.
*/
void ReplSource::sync_pullOpLog_applyOperation(BSONObj& op, OpTime *localLogTail) {
log( 6 ) << "processing op: " << op << endl;
// skip no-op
if ( op.getStringField( "op" )[ 0 ] == 'n' )
return;
char clientName[MaxClientLen];
const char *ns = op.getStringField("ns");
nsToClient(ns, clientName);
if ( *ns == '.' ) {
problem() << "skipping bad op in oplog: " << op.toString() << endl;
return;
}
else if ( *ns == 0 ) {
problem() << "halting replication, bad op in oplog:\n " << op.toString() << endl;
replAllDead = "bad object in oplog";
throw SyncException();
}
if ( !only.empty() && only != clientName )
return;
dblock lk;
if ( localLogTail && replPair && replPair->state == ReplPair::State_Master ) {
updateSetsWithLocalOps( *localLogTail, true ); // allow unlocking
updateSetsWithLocalOps( *localLogTail, false ); // don't allow unlocking or conversion to db backed storage
}
if ( replAllDead ) {
// hmmm why is this check here and not at top of this function? does it get set between top and here?
log() << "replAllDead, throwing SyncException\n";
throw SyncException();
}
bool justCreated;
try {
justCreated = setClientTempNs(ns);
} catch ( AssertionException& ) {
problem() << "skipping bad(?) op in oplog, setClient() failed, ns: '" << ns << "'\n";
addDbNextPass.erase(clientName);
return;
}
bool empty = clientIsEmpty();
bool incompleteClone = incompleteCloneDbs.count( clientName ) != 0;
log( 6 ) << "ns: " << ns << ", justCreated: " << justCreated << ", empty: " << empty << ", incompleteClone: " << incompleteClone << endl;
if ( justCreated || empty || incompleteClone ) {
// we must add to incomplete list now that setClient has been called
incompleteCloneDbs.insert( clientName );
if ( nClonedThisPass ) {
/* we only clone one database per pass, even if a lot need done. This helps us
avoid overflowing the master's transaction log by doing too much work before going
back to read more transactions. (Imagine a scenario of slave startup where we try to
clone 100 databases in one pass.)
*/
addDbNextPass.insert( clientName );
} else {
if ( incompleteClone ) {
log() << "An earlier initial clone of '" << clientName << "' did not complete, now resyncing." << endl;
}
save();
setClientTempNs( ns );
nClonedThisPass++;
resync(database->name);
addDbNextPass.erase(clientName);
incompleteCloneDbs.erase( clientName );
}
save();
} else {
bool mod;
if ( replPair && replPair->state == ReplPair::State_Master ) {
BSONObj id = idForOp( op, mod );
if ( !idTracker.haveId( ns, id ) ) {
applyOperation( op );
} else if ( idTracker.haveModId( ns, id ) ) {
log( 6 ) << "skipping operation matching mod id object " << op << endl;
BSONObj existing;
if ( Helpers::findOne( ns, id, existing ) )
logOp( "i", ns, existing );
} else {
log( 6 ) << "skipping operation matching changed id object " << op << endl;
}
} else {
applyOperation( op );
}
addDbNextPass.erase( clientName );
}
database = 0;
}
BSONObj ReplSource::idForOp( const BSONObj &op, bool &mod ) {
mod = false;
const char *opType = op.getStringField( "op" );
BSONObj o = op.getObjectField( "o" );
switch( opType[ 0 ] ) {
case 'i': {
BSONObjBuilder idBuilder;
BSONElement id;
if ( !o.getObjectID( id ) )
return BSONObj();
idBuilder.append( id );
return idBuilder.obj();
}
case 'u': {
BSONObj o2 = op.getObjectField( "o2" );
if ( strcmp( o2.firstElement().fieldName(), "_id" ) != 0 )
return BSONObj();
if ( o.firstElement().fieldName()[ 0 ] == '$' )
mod = true;
return o2;
}
case 'd': {
if ( opType[ 1 ] != '\0' )
return BSONObj(); // skip "db" op type
return o;
}
default:
break;
}
return BSONObj();
}
void ReplSource::updateSetsWithOp( const BSONObj &op, bool mayUnlock ) {
if ( mayUnlock ) {
idTracker.mayUpgradeStorage();
}
bool mod;
BSONObj id = idForOp( op, mod );
if ( !id.isEmpty() ) {
const char *ns = op.getStringField( "ns" );
// Since our range of local ops may not be the same as our peer's
// range of unapplied ops, it is always necessary to rewrite objects
// to the oplog after a mod update.
if ( mod )
idTracker.haveModId( ns, id, true );
idTracker.haveId( ns, id, true );
}
}
void ReplSource::syncToTailOfRemoteLog() {
string _ns = ns();
BSONObj last = conn->findOne( _ns.c_str(), Query().sort( BSON( "$natural" << -1 ) ) );
if ( !last.isEmpty() ) {
BSONElement ts = last.findElement( "ts" );
massert( "non Date ts found", ts.type() == Date );
syncedTo = OpTime( ts.date() );
}
}
OpTime ReplSource::nextLastSavedLocalTs() const {
setClient( "local.oplog.$main" );
auto_ptr< Cursor > c = findTableScan( "local.oplog.$main", BSON( "$natural" << -1 ) );
if ( c->ok() )
return OpTime( c->current().getField( "ts" ).date() );
return OpTime();
}
void ReplSource::setLastSavedLocalTs( const OpTime &nextLocalTs ) {
lastSavedLocalTs_ = nextLocalTs;
log( 3 ) << "updated lastSavedLocalTs_ to: " << lastSavedLocalTs_ << endl;
}
void ReplSource::resetSlave() {
massert( "request to kill slave replication falied",
conn->simpleCommand( "admin", 0, "forcedead" ) );
syncToTailOfRemoteLog();
{