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
|
/**
* Copyright (C) 2019-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.
*/
#pragma once
#include <vector>
#include "mongo/db/repl/base_cloner.h"
#include "mongo/db/repl/database_cloner.h"
#include "mongo/db/repl/initial_sync_base_cloner.h"
#include "mongo/db/repl/initial_sync_shared_data.h"
namespace mongo {
namespace repl {
class AllDatabaseCloner final : public InitialSyncBaseCloner {
public:
struct Stats {
size_t databasesCloned{0};
size_t databasesToClone{0};
long long dataSize{0};
std::vector<DatabaseCloner::Stats> databaseStats;
std::string toString() const;
BSONObj toBSON() const;
void append(BSONObjBuilder* builder) const;
};
AllDatabaseCloner(InitialSyncSharedData* sharedData,
const HostAndPort& source,
DBClientConnection* client,
StorageInterface* storageInterface,
ThreadPool* dbPool);
virtual ~AllDatabaseCloner() = default;
Stats getStats() const;
std::string toString() const;
protected:
ClonerStages getStages() final;
private:
friend class AllDatabaseClonerTest;
class ConnectStage : public ClonerStage<AllDatabaseCloner> {
public:
ConnectStage(std::string name, AllDatabaseCloner* cloner, ClonerRunFn stageFunc)
: ClonerStage<AllDatabaseCloner>(name, cloner, stageFunc){};
bool checkSyncSourceValidityOnRetry() final {
return false;
}
};
/**
* Validation function to ensure we connect only to primary or secondary nodes.
*
* Because the cloner connection is separate from the usual inter-node connection pool and
* did not have the 'hangUpOnStepDown:false' flag set in the initial isMaster request, we
* will always disconnect if the sync source transitions to a state other than PRIMARY
* or SECONDARY. It will not disconnect on a PRIMARY to SECONDARY or SECONDARY to PRIMARY
* transition because we no longer do that (the flag name is anachronistic). After
* disconnecting, this validation function will prevent us from reconnecting until the node
* re-enters PRIMARY or SECONDARY state.
*
* The reason this is necessary is that in 4.2, commands which read metadata (listDatabases,
* listCollections, listIndexes) succeed while the sync source is in RECOVERING or ROLLBACK.
* In those states, this metadata may be out of date compared to the end of the oplog. So
* we could for instance do a listCollections on a database while in RECOVERING, and miss an
* entire collection that was recently added. Then before we read any data (which would cause
* a failure) the node could finish recovery, and we could end up missing an entire collection.
* If the only data added to that collection was within the recovery period, the initial sync
* would succeed and we would have an inconsistent node. If other data was added we would
* invariant during oplog application with a NamespaceNotFound error.
*/
Status ensurePrimaryOrSecondary(const executor::RemoteCommandResponse& isMasterReply);
/**
* Stage function that makes a connection to the sync source.
*/
AfterStageBehavior connectStage();
/**
* Stage function that gets the wire version and initial sync ID.
*/
AfterStageBehavior getInitialSyncIdStage();
/**
* Stage function that retrieves database information from the sync source.
*/
AfterStageBehavior listDatabasesStage();
/**
*
* The postStage creates and runs the individual DatabaseCloners on each database found on
* the sync source.
*/
void postStage() final;
std::string describeForFuzzer(BaseClonerStage* stage) const final {
return "admin db: { " + stage->getName() + ": 1 }";
}
// All member variables are labeled with one of the following codes indicating the
// synchronization rules for accessing them.
//
// (R) Read-only in concurrent operation; no synchronization required.
// (S) Self-synchronizing; access according to classes own rules.
// (M) Reads and writes guarded by _mutex (defined in base class).
// (X) Access only allowed from the main flow of control called from run() or constructor.
// (MX) Write access with mutex from main flow of control, read access with mutex from other
// threads, read access allowed from main flow without mutex.
ConnectStage _connectStage; // (R)
ConnectStage _getInitialSyncIdStage; // (R)
ClonerStage<AllDatabaseCloner> _listDatabasesStage; // (R)
std::vector<std::string> _databases; // (X)
std::unique_ptr<DatabaseCloner> _currentDatabaseCloner; // (MX)
Stats _stats; // (MX)
};
} // namespace repl
} // namespace mongo
|
