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
|
/**
* Copyright (C) 2020-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 "mongo/db/repl/primary_only_service.h"
#include "mongo/db/s/resharding/donor_document_gen.h"
#include "mongo/s/resharding/type_collection_fields_gen.h"
namespace mongo {
constexpr StringData kReshardingDonorServiceName = "ReshardingDonorService"_sd;
class ReshardingDonorService final : public repl::PrimaryOnlyService {
public:
explicit ReshardingDonorService(ServiceContext* serviceContext)
: PrimaryOnlyService(serviceContext) {}
~ReshardingDonorService() = default;
StringData getServiceName() const override {
return kReshardingDonorServiceName;
}
NamespaceString getStateDocumentsNS() const override {
return NamespaceString::kDonorReshardingOperationsNamespace;
}
ThreadPool::Limits getThreadPoolLimits() const override {
// TODO Limit the size of ReshardingDonorService thread pool.
return ThreadPool::Limits();
}
std::shared_ptr<PrimaryOnlyService::Instance> constructInstance(
BSONObj initialState) const override;
};
/**
* Represents the current state of a resharding donor operation on this shard. This class drives
* state transitions and updates to underlying on-disk metadata.
*/
class DonorStateMachine final : public repl::PrimaryOnlyService::TypedInstance<DonorStateMachine> {
public:
explicit DonorStateMachine(const BSONObj& donorDoc);
void run(std::shared_ptr<executor::ScopedTaskExecutor> executor) noexcept override;
void interrupt(Status status) override{};
/**
* TODO(SERVER-50978) Report ReshardingDonorService Instances in currentOp().
*/
boost::optional<BSONObj> reportForCurrentOp(
MongoProcessInterface::CurrentOpConnectionsMode connMode,
MongoProcessInterface::CurrentOpSessionsMode sessionMode) noexcept override {
return boost::none;
}
void onReshardingFieldsChanges(
boost::optional<TypeCollectionReshardingFields> reshardingFields);
private:
// The following functions correspond to the actions to take at a particular donor state.
void _onPreparingToDonateCalculateMinFetchTimestampThenBeginDonating();
ExecutorFuture<void> _awaitAllRecipientsDoneApplyingThenStartMirroring(
const std::shared_ptr<executor::ScopedTaskExecutor>& executor);
ExecutorFuture<void> _awaitCoordinatorHasCommittedThenTransitionToDropping(
const std::shared_ptr<executor::ScopedTaskExecutor>& executor);
void _dropOriginalCollectionThenDeleteLocalState();
// Transitions the state on-disk and in-memory to 'endState'.
void _transitionState(DonorStateEnum endState,
boost::optional<Timestamp> minFetchTimestamp = boost::none);
// Transitions the state on-disk and in-memory to kError.
void _transitionStateToError(const Status& status);
// Updates the donor document on-disk and in-memory with the 'replacementDoc.'
void _updateDonorDocument(ReshardingDonorDocument&& replacementDoc);
// The in-memory representation of the underlying document in
// config.localReshardingOperations.donor.
ReshardingDonorDocument _donorDoc;
// Each promise below corresponds to a state on the donor state machine. They are listed in
// ascending order, such that the first promise below will be the first promise fulfilled.
SharedPromise<void> _allRecipientsDoneApplying;
SharedPromise<void> _coordinatorHasCommitted;
// The id both for the resharding operation and for the primary-only-service instance.
const UUID _id;
};
} // namespace mongo
|