/
dbclient_rs.cpp
1100 lines (873 loc) · 37.5 KB
/
dbclient_rs.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
// dbclient.cpp - connect to a Mongo database as a database, from C++
/* Copyright 2009 10gen Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "pch.h"
#include "dbclient.h"
#include "../bson/util/builder.h"
#include "../db/jsobj.h"
#include "../db/json.h"
#include "../db/dbmessage.h"
#include "connpool.h"
#include "dbclient_rs.h"
#include "../util/background.h"
namespace mongo {
// --------------------------------
// ----- ReplicaSetMonitor ---------
// --------------------------------
// global background job responsible for checking every X amount of time
class ReplicaSetMonitorWatcher : public BackgroundJob {
public:
ReplicaSetMonitorWatcher() : _safego("ReplicaSetMonitorWatcher::_safego") , _started(false) {}
virtual string name() const { return "ReplicaSetMonitorWatcher"; }
void safeGo() {
// check outside of lock for speed
if ( _started )
return;
scoped_lock lk( _safego );
if ( _started )
return;
_started = true;
go();
}
protected:
void run() {
log() << "starting" << endl;
while ( ! inShutdown() ) {
sleepsecs( 10 );
try {
ReplicaSetMonitor::checkAll( true );
}
catch ( std::exception& e ) {
error() << "check failed: " << e.what() << endl;
}
catch ( ... ) {
error() << "unkown error" << endl;
}
}
}
mongo::mutex _safego;
bool _started;
} replicaSetMonitorWatcher;
string seedString( const vector<HostAndPort>& servers ){
string seedStr;
for ( unsigned i = 0; i < servers.size(); i++ ){
seedStr += servers[i].toString();
if( i < servers.size() - 1 ) seedStr += ",";
}
return seedStr;
}
ReplicaSetMonitor::ReplicaSetMonitor( const string& name , const vector<HostAndPort>& servers )
: _lock( "ReplicaSetMonitor instance" ) , _checkConnectionLock( "ReplicaSetMonitor check connection lock" ), _name( name ) , _master(-1), _nextSlave(0) {
uassert( 13642 , "need at least 1 node for a replica set" , servers.size() > 0 );
if ( _name.size() == 0 ) {
warning() << "replica set name empty, first node: " << servers[0] << endl;
}
log() << "starting new replica set monitor for replica set " << _name << " with seed of " << seedString( servers ) << endl;
string errmsg;
for ( unsigned i = 0; i < servers.size(); i++ ) {
// Don't check servers we have already
if( _find_inlock( servers[i] ) >= 0 ) continue;
auto_ptr<DBClientConnection> conn( new DBClientConnection( true , 0, 5.0 ) );
try{
if( ! conn->connect( servers[i] , errmsg ) ){
throw DBException( errmsg, 15928 );
}
log() << "successfully connected to seed " << servers[i] << " for replica set " << this->_name << endl;
}
catch( DBException& e ){
log() << "error connecting to seed " << servers[i] << causedBy( e ) << endl;
// skip seeds that don't work
continue;
}
string maybePrimary;
_checkConnection( conn.get(), maybePrimary, false, -1 );
}
// Check everything to get the first data
_check( true );
log() << "replica set monitor for replica set " << _name << " started, address is " << getServerAddress() << endl;
}
ReplicaSetMonitor::~ReplicaSetMonitor() {
_nodes.clear();
_master = -1;
}
ReplicaSetMonitorPtr ReplicaSetMonitor::get( const string& name , const vector<HostAndPort>& servers ) {
scoped_lock lk( _setsLock );
ReplicaSetMonitorPtr& m = _sets[name];
if ( ! m )
m.reset( new ReplicaSetMonitor( name , servers ) );
replicaSetMonitorWatcher.safeGo();
return m;
}
ReplicaSetMonitorPtr ReplicaSetMonitor::get( const string& name ) {
scoped_lock lk( _setsLock );
map<string,ReplicaSetMonitorPtr>::const_iterator i = _sets.find( name );
if ( i == _sets.end() )
return ReplicaSetMonitorPtr();
return i->second;
}
void ReplicaSetMonitor::checkAll( bool checkAllSecondaries ) {
set<string> seen;
while ( true ) {
ReplicaSetMonitorPtr m;
{
scoped_lock lk( _setsLock );
for ( map<string,ReplicaSetMonitorPtr>::iterator i=_sets.begin(); i!=_sets.end(); ++i ) {
string name = i->first;
if ( seen.count( name ) )
continue;
LOG(1) << "checking replica set: " << name << endl;
seen.insert( name );
m = i->second;
break;
}
}
if ( ! m )
break;
m->check( checkAllSecondaries );
}
}
void ReplicaSetMonitor::setConfigChangeHook( ConfigChangeHook hook ) {
massert( 13610 , "ConfigChangeHook already specified" , _hook == 0 );
_hook = hook;
}
string ReplicaSetMonitor::getServerAddress() const {
scoped_lock lk( _lock );
return _getServerAddress_inlock();
}
string ReplicaSetMonitor::_getServerAddress_inlock() const {
StringBuilder ss;
if ( _name.size() )
ss << _name << "/";
for ( unsigned i=0; i<_nodes.size(); i++ ) {
if ( i > 0 )
ss << ",";
ss << _nodes[i].addr.toString();
}
return ss.str();
}
bool ReplicaSetMonitor::contains( const string& server ) const {
scoped_lock lk( _lock );
for ( unsigned i=0; i<_nodes.size(); i++ ) {
if ( _nodes[i].addr == server )
return true;
}
return false;
}
void ReplicaSetMonitor::notifyFailure( const HostAndPort& server ) {
scoped_lock lk( _lock );
if ( _master >= 0 && _master < (int)_nodes.size() ) {
if ( server == _nodes[_master].addr ) {
_nodes[_master].ok = false;
_master = -1;
}
}
}
HostAndPort ReplicaSetMonitor::getMaster() {
{
scoped_lock lk( _lock );
assert(_master < static_cast<int>(_nodes.size()));
if ( _master >= 0 && _nodes[_master].ok )
return _nodes[_master].addr;
}
_check( false );
scoped_lock lk( _lock );
uassert( 10009 , str::stream() << "ReplicaSetMonitor no master found for set: " << _name , _master >= 0 );
assert(_master < static_cast<int>(_nodes.size()));
return _nodes[_master].addr;
}
HostAndPort ReplicaSetMonitor::getSlave( const HostAndPort& prev ) {
// make sure its valid
bool wasFound = false;
// This is always true, since checked in port()
assert( prev.port() >= 0 );
if( prev.host().size() ){
scoped_lock lk( _lock );
for ( unsigned i=0; i<_nodes.size(); i++ ) {
if ( prev != _nodes[i].addr )
continue;
wasFound = true;
if ( _nodes[i].okForSecondaryQueries() )
return prev;
break;
}
}
if( prev.host().size() ){
if( wasFound ){ LOG(1) << "slave '" << prev << "' is no longer ok to use" << endl; }
else{ LOG(1) << "slave '" << prev << "' was not found in the replica set" << endl; }
}
else LOG(1) << "slave '" << prev << "' is not initialized or invalid" << endl;
return getSlave();
}
HostAndPort ReplicaSetMonitor::getSlave() {
LOG(2) << "dbclient_rs getSlave " << getServerAddress() << endl;
scoped_lock lk( _lock );
for ( unsigned ii = 0; ii < _nodes.size(); ii++ ) {
_nextSlave = ( _nextSlave + 1 ) % _nodes.size();
if ( _nextSlave != _master ) {
if ( _nodes[ _nextSlave ].okForSecondaryQueries() )
return _nodes[ _nextSlave ].addr;
LOG(2) << "dbclient_rs getSlave not selecting " << _nodes[_nextSlave] << ", not currently okForSecondaryQueries" << endl;
}
}
if( _master >= 0 ) {
assert( static_cast<unsigned>(_master) < _nodes.size() );
LOG(2) << "dbclient_rs getSlave no member in secondary state found, returning primary " << _nodes[ _master ] << endl;
return _nodes[_master].addr;
}
LOG(2) << "dbclient_rs getSlave no suitable member found, returning first node " << _nodes[ 0 ] << endl;
assert( _nodes.size() > 0 );
return _nodes[0].addr;
}
/**
* notify the monitor that server has failed
*/
void ReplicaSetMonitor::notifySlaveFailure( const HostAndPort& server ) {
int x = _find( server );
if ( x >= 0 ) {
scoped_lock lk( _lock );
_nodes[x].ok = false;
}
}
void ReplicaSetMonitor::_checkStatus( const string& hostAddr ) {
BSONObj status;
/* replSetGetStatus requires admin auth so use a connection from the pool,
* which are authenticated with the keyFile credentials.
*/
ScopedDbConnection authenticatedConn( hostAddr );
if ( !authenticatedConn->runCommand( "admin", BSON( "replSetGetStatus" << 1 ), status )) {
LOG(1) << "dbclient_rs replSetGetStatus failed" << endl;
authenticatedConn.done(); // connection worked properly, but we got an error from server
return;
}
// Make sure we return when finished
authenticatedConn.done();
if( !status.hasField("members") ) {
log() << "dbclient_rs error expected members field in replSetGetStatus result" << endl;
return;
}
if( status["members"].type() != Array) {
log() << "dbclient_rs error expected members field in replSetGetStatus result to be an array" << endl;
return;
}
BSONObjIterator hi(status["members"].Obj());
while (hi.more()) {
BSONObj member = hi.next().Obj();
string host = member["name"].String();
int m = -1;
if ((m = _find(host)) < 0) {
continue;
}
double state = member["state"].Number();
if (member["health"].Number() == 1 && (state == 1 || state == 2)) {
scoped_lock lk( _lock );
_nodes[m].ok = true;
}
else {
scoped_lock lk( _lock );
_nodes[m].ok = false;
}
}
}
NodeDiff ReplicaSetMonitor::_getHostDiff_inlock( const BSONObj& hostList ){
NodeDiff diff;
set<int> nodesFound;
int index = 0;
BSONObjIterator hi( hostList );
while( hi.more() ){
string toCheck = hi.next().String();
int nodeIndex = _find_inlock( toCheck );
// Node-to-add
if( nodeIndex < 0 ) diff.first.insert( toCheck );
else nodesFound.insert( nodeIndex );
index++;
}
for( size_t i = 0; i < _nodes.size(); i++ ){
if( nodesFound.find( static_cast<int>(i) ) == nodesFound.end() ) diff.second.insert( static_cast<int>(i) );
}
return diff;
}
bool ReplicaSetMonitor::_shouldChangeHosts( const BSONObj& hostList, bool inlock ){
int origHosts = 0;
if( ! inlock ){
scoped_lock lk( _lock );
origHosts = _nodes.size();
}
else origHosts = _nodes.size();
int numHosts = 0;
bool changed = false;
BSONObjIterator hi(hostList);
while ( hi.more() ) {
string toCheck = hi.next().String();
numHosts++;
int index = 0;
if( ! inlock ) index = _find( toCheck );
else index = _find_inlock( toCheck );
if ( index >= 0 ) continue;
changed = true;
break;
}
return (changed || origHosts != numHosts) && numHosts > 0;
}
void ReplicaSetMonitor::_checkHosts( const BSONObj& hostList, bool& changed ) {
// Fast path, still requires intermittent locking
if( ! _shouldChangeHosts( hostList, false ) ){
changed = false;
return;
}
// Slow path, double-checked though
scoped_lock lk( _lock );
// Our host list may have changed while waiting for another thread in the meantime,
// so double-check here
// TODO: Do we really need this much protection, this should be pretty rare and not
// triggered from lots of threads, duping old behavior for safety
if( ! _shouldChangeHosts( hostList, true ) ){
changed = false;
return;
}
// LogLevel can be pretty low, since replica set reconfiguration should be pretty rare and
// we want to record our changes
log() << "changing hosts to " << hostList << " from " << _getServerAddress_inlock() << endl;
NodeDiff diff = _getHostDiff_inlock( hostList );
set<string> added = diff.first;
set<int> removed = diff.second;
assert( added.size() > 0 || removed.size() > 0 );
changed = true;
// Delete from the end so we don't invalidate as we delete, delete indices are ascending
for( set<int>::reverse_iterator i = removed.rbegin(), end = removed.rend(); i != end; ++i ){
log() << "erasing host " << _nodes[ *i ] << " from replica set " << this->_name << endl;
_nodes.erase( _nodes.begin() + *i );
}
// Add new nodes
for( set<string>::iterator i = added.begin(), end = added.end(); i != end; ++i ){
log() << "trying to add new host " << *i << " to replica set " << this->_name << endl;
// Connect to new node
HostAndPort h( *i );
DBClientConnection * newConn = new DBClientConnection( true, 0, 5.0 );
string errmsg;
try{
if( ! newConn->connect( h , errmsg ) ){
throw DBException( errmsg, 15927 );
}
log() << "successfully connected to new host " << *i << " in replica set " << this->_name << endl;
}
catch( DBException& e ){
warning() << "cannot connect to new host " << *i << " to replica set " << this->_name << causedBy( e ) << endl;
}
_nodes.push_back( Node( h , newConn ) );
}
// Invalidate the cached _master index since the _nodes structure has
// already been modified.
_master = -1;
}
bool ReplicaSetMonitor::_checkConnection( DBClientConnection* conn,
string& maybePrimary, bool verbose, int nodesOffset ) {
assert( conn );
scoped_lock lk( _checkConnectionLock );
bool isMaster = false;
bool changed = false;
bool errorOccured = false;
if ( nodesOffset >= 0 ){
scoped_lock lk( _lock );
if ( !_checkConnMatch_inlock( conn, nodesOffset )) {
/* Another thread modified _nodes -> invariant broken.
* This also implies that another thread just passed
* through here and refreshed _nodes. So no need to do
* duplicate work.
*/
return false;
}
}
try {
Timer t;
BSONObj o;
conn->isMaster( isMaster, &o );
if ( o["setName"].type() != String || o["setName"].String() != _name ) {
warning() << "node: " << conn->getServerAddress()
<< " isn't a part of set: " << _name
<< " ismaster: " << o << endl;
if ( nodesOffset >= 0 ) {
scoped_lock lk( _lock );
_nodes[nodesOffset].ok = false;
}
return false;
}
if ( nodesOffset >= 0 ) {
scoped_lock lk( _lock );
_nodes[nodesOffset].pingTimeMillis = t.millis();
_nodes[nodesOffset].hidden = o["hidden"].trueValue();
_nodes[nodesOffset].secondary = o["secondary"].trueValue();
_nodes[nodesOffset].ismaster = o["ismaster"].trueValue();
_nodes[nodesOffset].lastIsMaster = o.copy();
}
log( ! verbose ) << "ReplicaSetMonitor::_checkConnection: " << conn->toString()
<< ' ' << o << endl;
// add other nodes
BSONArrayBuilder b;
if ( o["hosts"].type() == Array ) {
if ( o["primary"].type() == String )
maybePrimary = o["primary"].String();
BSONObjIterator it( o["hosts"].Obj() );
while( it.more() ) b.append( it.next() );
}
if (o.hasField("passives") && o["passives"].type() == Array) {
BSONObjIterator it( o["passives"].Obj() );
while( it.more() ) b.append( it.next() );
}
_checkHosts( b.arr(), changed);
_checkStatus( conn->getServerAddress() );
}
catch ( std::exception& e ) {
log( ! verbose ) << "ReplicaSetMonitor::_checkConnection: caught exception "
<< conn->toString() << ' ' << e.what() << endl;
errorOccured = true;
}
if ( errorOccured && nodesOffset >= 0 ) {
scoped_lock lk( _lock );
if (_checkConnMatch_inlock(conn, nodesOffset)) {
// Make sure _checkHosts didn't modify the _nodes structure
_nodes[nodesOffset].ok = false;
}
}
if ( changed && _hook )
_hook( this );
return isMaster;
}
void ReplicaSetMonitor::_check( bool checkAllSecondaries ) {
LOG(1) << "_check : " << getServerAddress() << endl;
int newMaster = -1;
shared_ptr<DBClientConnection> nodeConn;
for ( int retry = 0; retry < 2; retry++ ) {
bool triedQuickCheck = false;
if ( !checkAllSecondaries ) {
scoped_lock lk( _lock );
assert(_master < static_cast<int>(_nodes.size()));
if ( _master >= 0 ) {
/* Nothing else to do since another thread already
* found the _master
*/
return;
}
}
for ( unsigned i = 0; /* should not check while outside of lock! */ ; i++ ) {
{
scoped_lock lk( _lock );
if ( i >= _nodes.size() ) break;
nodeConn = _nodes[i].conn;
}
string maybePrimary;
if ( _checkConnection( nodeConn.get(), maybePrimary, retry, i ) ) {
scoped_lock lk( _lock );
if ( _checkConnMatch_inlock( nodeConn.get(), i )) {
_master = i;
newMaster = i;
if ( !checkAllSecondaries )
return;
}
else {
/*
* Somebody modified _nodes and most likely set the new
* _master, so try again.
*/
break;
}
}
if ( ! triedQuickCheck && ! maybePrimary.empty() ) {
int probablePrimaryIdx = -1;
shared_ptr<DBClientConnection> probablePrimaryConn;
{
scoped_lock lk( _lock );
probablePrimaryIdx = _find_inlock( maybePrimary );
if (probablePrimaryIdx >= 0) {
probablePrimaryConn = _nodes[probablePrimaryIdx].conn;
}
}
if ( probablePrimaryIdx >= 0 ) {
triedQuickCheck = true;
string dummy;
if ( _checkConnection( probablePrimaryConn.get(), dummy,
false, probablePrimaryIdx ) ) {
scoped_lock lk( _lock );
if ( _checkConnMatch_inlock( probablePrimaryConn.get(),
probablePrimaryIdx )) {
_master = probablePrimaryIdx;
newMaster = probablePrimaryIdx;
if ( ! checkAllSecondaries )
return;
}
else {
/*
* Somebody modified _nodes and most likely set the
* new _master, so try again.
*/
break;
}
}
}
}
}
if ( newMaster >= 0 )
return;
sleepsecs( 1 );
}
}
void ReplicaSetMonitor::check( bool checkAllSecondaries ) {
shared_ptr<DBClientConnection> masterConn;
{
scoped_lock lk( _lock );
// first see if the current master is fine
if ( _master >= 0 ) {
assert(_master < static_cast<int>(_nodes.size()));
masterConn = _nodes[_master].conn;
}
}
if ( masterConn.get() != NULL ) {
string temp;
if ( _checkConnection( masterConn.get(), temp, false, _master )) {
if ( ! checkAllSecondaries ) {
// current master is fine, so we're done
return;
}
}
}
// we either have no master, or the current is dead
_check( checkAllSecondaries );
}
int ReplicaSetMonitor::_find( const string& server ) const {
scoped_lock lk( _lock );
return _find_inlock( server );
}
int ReplicaSetMonitor::_find_inlock( const string& server ) const {
const size_t size = _nodes.size();
for ( unsigned i = 0; i < size; i++ ) {
if ( _nodes[i].addr == server ) {
return i;
}
}
return -1;
}
void ReplicaSetMonitor::appendInfo( BSONObjBuilder& b ) const {
scoped_lock lk( _lock );
BSONArrayBuilder hosts( b.subarrayStart( "hosts" ) );
for ( unsigned i=0; i<_nodes.size(); i++ ) {
hosts.append( BSON( "addr" << _nodes[i].addr <<
// "lastIsMaster" << _nodes[i].lastIsMaster << // this is a potential race, so only used when debugging
"ok" << _nodes[i].ok <<
"ismaster" << _nodes[i].ismaster <<
"hidden" << _nodes[i].hidden <<
"secondary" << _nodes[i].secondary <<
"pingTimeMillis" << _nodes[i].pingTimeMillis ) );
}
hosts.done();
b.append( "master" , _master );
b.append( "nextSlave" , _nextSlave );
}
bool ReplicaSetMonitor::_checkConnMatch_inlock( DBClientConnection* conn,
size_t nodeOffset ) const {
return ( nodeOffset < _nodes.size() &&
conn->getServerAddress() == _nodes[nodeOffset].conn->getServerAddress() );
}
mongo::mutex ReplicaSetMonitor::_setsLock( "ReplicaSetMonitor" );
map<string,ReplicaSetMonitorPtr> ReplicaSetMonitor::_sets;
ReplicaSetMonitor::ConfigChangeHook ReplicaSetMonitor::_hook;
// --------------------------------
// ----- DBClientReplicaSet ---------
// --------------------------------
DBClientReplicaSet::DBClientReplicaSet( const string& name , const vector<HostAndPort>& servers, double so_timeout )
: _monitor( ReplicaSetMonitor::get( name , servers ) ),
_so_timeout( so_timeout ) {
}
DBClientReplicaSet::~DBClientReplicaSet() {
}
DBClientConnection * DBClientReplicaSet::checkMaster() {
HostAndPort h = _monitor->getMaster();
if ( h == _masterHost && _master ) {
// a master is selected. let's just make sure connection didn't die
if ( ! _master->isFailed() )
return _master.get();
_monitor->notifyFailure( _masterHost );
}
_masterHost = _monitor->getMaster();
_master.reset( new DBClientConnection( true , this , _so_timeout ) );
string errmsg;
if ( ! _master->connect( _masterHost , errmsg ) ) {
_monitor->notifyFailure( _masterHost );
uasserted( 13639 , str::stream() << "can't connect to new replica set master [" << _masterHost.toString() << "] err: " << errmsg );
}
_auth( _master.get() );
return _master.get();
}
DBClientConnection * DBClientReplicaSet::checkSlave() {
HostAndPort h = _monitor->getSlave( _slaveHost );
if ( h == _slaveHost && _slave ) {
if ( ! _slave->isFailed() )
return _slave.get();
_monitor->notifySlaveFailure( _slaveHost );
_slaveHost = _monitor->getSlave();
}
else {
_slaveHost = h;
}
_slave.reset( new DBClientConnection( true , this , _so_timeout ) );
_slave->connect( _slaveHost );
_auth( _slave.get() );
return _slave.get();
}
void DBClientReplicaSet::_auth( DBClientConnection * conn ) {
for ( list<AuthInfo>::iterator i=_auths.begin(); i!=_auths.end(); ++i ) {
const AuthInfo& a = *i;
string errmsg;
if ( ! conn->auth( a.dbname , a.username , a.pwd , errmsg, a.digestPassword ) )
warning() << "cached auth failed for set: " << _monitor->getName() << " db: " << a.dbname << " user: " << a.username << endl;
}
}
DBClientConnection& DBClientReplicaSet::masterConn() {
return *checkMaster();
}
DBClientConnection& DBClientReplicaSet::slaveConn() {
return *checkSlave();
}
bool DBClientReplicaSet::connect() {
try {
checkMaster();
}
catch (AssertionException&) {
if (_master && _monitor) {
_monitor->notifyFailure(_masterHost);
}
return false;
}
return true;
}
bool DBClientReplicaSet::auth(const string &dbname, const string &username, const string &pwd, string& errmsg, bool digestPassword ) {
DBClientConnection * m = checkMaster();
// first make sure it actually works
if( ! m->auth(dbname, username, pwd, errmsg, digestPassword ) )
return false;
// now that it does, we should save so that for a new node we can auth
_auths.push_back( AuthInfo( dbname , username , pwd , digestPassword ) );
return true;
}
// ------------- simple functions -----------------
void DBClientReplicaSet::insert( const string &ns , BSONObj obj , int flags) {
checkMaster()->insert(ns, obj, flags);
}
void DBClientReplicaSet::insert( const string &ns, const vector< BSONObj >& v , int flags) {
checkMaster()->insert(ns, v, flags);
}
void DBClientReplicaSet::remove( const string &ns , Query obj , bool justOne ) {
checkMaster()->remove(ns, obj, justOne);
}
void DBClientReplicaSet::update( const string &ns , Query query , BSONObj obj , bool upsert , bool multi ) {
return checkMaster()->update(ns, query, obj, upsert,multi);
}
auto_ptr<DBClientCursor> DBClientReplicaSet::query(const string &ns, Query query, int nToReturn, int nToSkip,
const BSONObj *fieldsToReturn, int queryOptions, int batchSize) {
if ( queryOptions & QueryOption_SlaveOk ) {
// we're ok sending to a slave
// we'll try 2 slaves before just using master
// checkSlave will try a different slave automatically after a failure
for ( int i=0; i<3; i++ ) {
try {
return checkSlaveQueryResult( checkSlave()->query(ns,query,nToReturn,nToSkip,fieldsToReturn,queryOptions,batchSize) );
}
catch ( DBException &e ) {
LOG(1) << "can't query replica set slave " << i << " : " << _slaveHost << causedBy( e ) << endl;
}
}
}
return checkMaster()->query(ns,query,nToReturn,nToSkip,fieldsToReturn,queryOptions,batchSize);
}
BSONObj DBClientReplicaSet::findOne(const string &ns, const Query& query, const BSONObj *fieldsToReturn, int queryOptions) {
if ( queryOptions & QueryOption_SlaveOk ) {
// we're ok sending to a slave
// we'll try 2 slaves before just using master
// checkSlave will try a different slave automatically after a failure
for ( int i=0; i<3; i++ ) {
try {
return checkSlave()->findOne(ns,query,fieldsToReturn,queryOptions);
}
catch ( DBException &e ) {
LOG(1) << "can't findone replica set slave " << i << " : " << _slaveHost << causedBy( e ) << endl;
}
}
}
return checkMaster()->findOne(ns,query,fieldsToReturn,queryOptions);
}
void DBClientReplicaSet::killCursor( long long cursorID ) {
// we should neve call killCursor on a replica set conncetion
// since we don't know which server it belongs to
// can't assume master because of slave ok
// and can have a cursor survive a master change
assert(0);
}
void DBClientReplicaSet::isntMaster() {
log() << "got not master for: " << _masterHost << endl;
_monitor->notifyFailure( _masterHost );
_master.reset();
}
auto_ptr<DBClientCursor> DBClientReplicaSet::checkSlaveQueryResult( auto_ptr<DBClientCursor> result ){
if ( result.get() == NULL ) return result;
BSONObj error;
bool isError = result->peekError( &error );
if( ! isError ) return result;
// We only check for "not master or secondary" errors here
// If the error code here ever changes, we need to change this code also
BSONElement code = error["code"];
if( code.isNumber() && code.Int() == 13436 /* not master or secondary */ ){
isntSecondary();
throw DBException( str::stream() << "slave " << _slaveHost.toString() << " is no longer secondary", 14812 );
}
return result;
}
void DBClientReplicaSet::isntSecondary() {
log() << "slave no longer has secondary status: " << _slaveHost << endl;
// Failover to next slave
_monitor->notifySlaveFailure( _slaveHost );
_slave.reset();
}
void DBClientReplicaSet::say( Message& toSend, bool isRetry ) {
if( ! isRetry )
_lazyState = LazyState();
int lastOp = -1;
bool slaveOk = false;
if ( ( lastOp = toSend.operation() ) == dbQuery ) {
// TODO: might be possible to do this faster by changing api
DbMessage dm( toSend );
QueryMessage qm( dm );
if ( ( slaveOk = ( qm.queryOptions & QueryOption_SlaveOk ) ) ) {
for ( int i = _lazyState._retries; i < 3; i++ ) {
try {
DBClientConnection* slave = checkSlave();
slave->say( toSend );
_lazyState._lastOp = lastOp;
_lazyState._slaveOk = slaveOk;
_lazyState._retries = i;
_lazyState._lastClient = slave;
return;
}
catch ( DBException &e ) {
LOG(1) << "can't callLazy replica set slave " << i << " : " << _slaveHost << causedBy( e ) << endl;
}
}
}
}
DBClientConnection* master = checkMaster();
master->say( toSend );
_lazyState._lastOp = lastOp;
_lazyState._slaveOk = slaveOk;
_lazyState._retries = 3;
_lazyState._lastClient = master;
return;
}
bool DBClientReplicaSet::recv( Message& m ) {
assert( _lazyState._lastClient );
// TODO: It would be nice if we could easily wrap a conn error as a result error
try {
return _lazyState._lastClient->recv( m );
}
catch( DBException& e ){
log() << "could not receive data from " << _lazyState._lastClient << causedBy( e ) << endl;
return false;
}
}
void DBClientReplicaSet::checkResponse( const char* data, int nReturned, bool* retry, string* targetHost ){
// For now, do exactly as we did before, so as not to break things. In general though, we
// should fix this so checkResponse has a more consistent contract.
if( ! retry ){
if( _lazyState._lastClient )