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
|
/**
* Copyright (C) 2012 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/>.
*
* 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::kReplication
#include "mongo/platform/basic.h"
#include "mongo/db/repl/oplogreader.h"
#include <string>
#include "mongo/base/counter.h"
#include "mongo/client/dbclientinterface.h"
#include "mongo/db/auth/authorization_manager.h"
#include "mongo/db/auth/authorization_manager_global.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/internal_user_auth.h"
#include "mongo/db/commands/server_status_metric.h"
#include "mongo/db/dbhelpers.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/repl/minvalid.h"
#include "mongo/db/repl/oplog.h"
#include "mongo/db/repl/replication_coordinator.h"
#include "mongo/executor/network_interface.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/log.h"
namespace mongo {
using std::shared_ptr;
using std::endl;
using std::string;
namespace repl {
const BSONObj reverseNaturalObj = BSON("$natural" << -1);
// number of readers created;
// this happens when the source source changes, a reconfig/network-error or the cursor dies
static Counter64 readersCreatedStats;
static ServerStatusMetricField<Counter64> displayReadersCreated("repl.network.readersCreated",
&readersCreatedStats);
bool replAuthenticate(DBClientBase* conn) {
if (!getGlobalAuthorizationManager()->isAuthEnabled())
return true;
if (!isInternalAuthSet())
return false;
return conn->authenticateInternalUser();
}
const Seconds OplogReader::kSocketTimeout(30);
OplogReader::OplogReader() {
_tailingQueryOptions = QueryOption_SlaveOk;
_tailingQueryOptions |= QueryOption_CursorTailable | QueryOption_OplogReplay;
/* TODO: slaveOk maybe shouldn't use? */
_tailingQueryOptions |= QueryOption_AwaitData;
readersCreatedStats.increment();
}
bool OplogReader::connect(const HostAndPort& host) {
if (conn() == NULL || _host != host) {
resetConnection();
_conn = shared_ptr<DBClientConnection>(
new DBClientConnection(false, durationCount<Seconds>(kSocketTimeout)));
string errmsg;
if (!_conn->connect(host, errmsg) ||
(getGlobalAuthorizationManager()->isAuthEnabled() && !replAuthenticate(_conn.get()))) {
resetConnection();
error() << errmsg << endl;
return false;
}
_conn->port().tag |= executor::NetworkInterface::kMessagingPortKeepOpen;
_host = host;
}
return true;
}
void OplogReader::tailCheck() {
if (cursor.get() && cursor->isDead()) {
log() << "old cursor isDead, will initiate a new one" << std::endl;
resetCursor();
}
}
void OplogReader::query(
const char* ns, Query query, int nToReturn, int nToSkip, const BSONObj* fields) {
cursor.reset(
_conn->query(ns, query, nToReturn, nToSkip, fields, QueryOption_SlaveOk).release());
}
void OplogReader::tailingQuery(const char* ns, const BSONObj& query) {
verify(!haveCursor());
LOG(2) << ns << ".find(" << query.toString() << ')' << endl;
cursor.reset(_conn->query(ns, query, 0, 0, nullptr, _tailingQueryOptions).release());
}
void OplogReader::tailingQueryGTE(const char* ns, Timestamp optime) {
BSONObjBuilder gte;
gte.append("$gte", optime);
BSONObjBuilder query;
query.append("ts", gte.done());
tailingQuery(ns, query.done());
}
HostAndPort OplogReader::getHost() const {
return _host;
}
void OplogReader::connectToSyncSource(OperationContext* txn,
const OpTime& lastOpTimeFetched,
ReplicationCoordinator* replCoord) {
const Timestamp sentinelTimestamp(duration_cast<Seconds>(Milliseconds(curTimeMillis64())), 0);
const OpTime sentinel(sentinelTimestamp, std::numeric_limits<long long>::max());
OpTime oldestOpTimeSeen = sentinel;
invariant(conn() == NULL);
while (true) {
HostAndPort candidate = replCoord->chooseNewSyncSource(lastOpTimeFetched.getTimestamp());
if (candidate.empty()) {
if (oldestOpTimeSeen == sentinel) {
// If, in this invocation of connectToSyncSource(), we did not successfully
// connect to any node ahead of us,
// we apparently have no sync sources to connect to.
// This situation is common; e.g. if there are no writes to the primary at
// the moment.
return;
}
// Connected to at least one member, but in all cases we were too stale to use them
// as a sync source.
error() << "too stale to catch up -- entering maintenance mode";
log() << "our last optime : " << lastOpTimeFetched;
log() << "oldest available is " << oldestOpTimeSeen;
log() << "See http://dochub.mongodb.org/core/resyncingaverystalereplicasetmember";
setMinValid(txn, {lastOpTimeFetched, oldestOpTimeSeen});
auto status = replCoord->setMaintenanceMode(true);
if (!status.isOK()) {
warning() << "Failed to transition into maintenance mode.";
}
bool worked = replCoord->setFollowerMode(MemberState::RS_RECOVERING);
if (!worked) {
warning() << "Failed to transition into " << MemberState(MemberState::RS_RECOVERING)
<< ". Current state: " << replCoord->getMemberState();
}
return;
}
if (!connect(candidate)) {
LOG(2) << "can't connect to " << candidate.toString() << " to read operations";
resetConnection();
replCoord->blacklistSyncSource(candidate, Date_t::now() + Seconds(10));
continue;
}
// Read the first (oldest) op and confirm that it's not newer than our last
// fetched op. Otherwise, we have fallen off the back of that source's oplog.
BSONObj remoteOldestOp(findOne(rsOplogName.c_str(), Query()));
OpTime remoteOldOpTime =
fassertStatusOK(28776, OpTime::parseFromOplogEntry(remoteOldestOp));
// remoteOldOpTime may come from a very old config, so we cannot compare their terms.
if (!lastOpTimeFetched.isNull() &&
lastOpTimeFetched.getTimestamp() < remoteOldOpTime.getTimestamp()) {
// We're too stale to use this sync source.
resetConnection();
replCoord->blacklistSyncSource(candidate, Date_t::now() + Minutes(1));
if (oldestOpTimeSeen.getTimestamp() > remoteOldOpTime.getTimestamp()) {
warning() << "we are too stale to use " << candidate.toString()
<< " as a sync source";
oldestOpTimeSeen = remoteOldOpTime;
}
continue;
}
// TODO: If we were too stale (recovering with maintenance mode on), then turn it off, to
// allow becoming secondary/etc.
// Got a valid sync source.
return;
} // while (true)
}
} // namespace repl
} // namespace mongo
|
