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
|
/**
* Copyright (C) 2018-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.
*/
#include "mongo/platform/basic.h"
#include "mongo/db/keys_collection_cache.h"
#include "mongo/db/keys_collection_client.h"
#include "mongo/db/repl/replication_coordinator.h"
#include "mongo/util/str.h"
namespace mongo {
KeysCollectionCache::KeysCollectionCache(std::string purpose, KeysCollectionClient* client)
: _purpose(std::move(purpose)), _client(client) {}
StatusWith<KeysCollectionDocument> KeysCollectionCache::refresh(OperationContext* opCtx) {
// Don't allow this to read during initial sync because it will read at the initialDataTimestamp
// and that could conflict with reconstructing prepared transactions using the
// initialDataTimestamp as the prepareTimestamp.
if (repl::ReplicationCoordinator::get(opCtx) &&
repl::ReplicationCoordinator::get(opCtx)->getMemberState().startup2()) {
return {ErrorCodes::InitialSyncActive,
"Cannot refresh keys collection cache during initial sync"};
}
// Don't allow this to read during rollback as the storage engine requires exclusive access.
if (repl::ReplicationCoordinator::get(opCtx) &&
repl::ReplicationCoordinator::get(opCtx)->getMemberState().rollback()) {
return {ErrorCodes::InterruptedDueToReplStateChange,
"Cannot refresh keys collection cache during rollback"};
}
auto refreshStatus = _refreshExternalKeys(opCtx);
if (!refreshStatus.isOK()) {
return refreshStatus;
}
return _refreshInternalKeys(opCtx);
}
StatusWith<KeysCollectionDocument> KeysCollectionCache::_refreshInternalKeys(
OperationContext* opCtx) {
LogicalTime newerThanThis;
decltype(_internalKeysCache)::size_type originalSize = 0;
{
stdx::lock_guard<Latch> lk(_cacheMutex);
auto iter = _internalKeysCache.crbegin();
if (iter != _internalKeysCache.crend()) {
newerThanThis = iter->second.getExpiresAt();
}
originalSize = _internalKeysCache.size();
}
auto refreshStatus =
_client->getNewInternalKeys(opCtx, _purpose, newerThanThis, true /* tryUseMajority */);
if (!refreshStatus.isOK()) {
return refreshStatus.getStatus();
}
auto& newKeys = refreshStatus.getValue();
stdx::lock_guard<Latch> lk(_cacheMutex);
if (originalSize > _internalKeysCache.size()) {
// _internalKeysCache cleared while we were getting the new keys, just return the newest key
// without touching the _internalKeysCache so the next refresh will populate it properly.
// Note: newKeys are sorted.
if (!newKeys.empty()) {
return std::move(newKeys.back());
}
}
for (auto&& key : newKeys) {
_internalKeysCache.emplace(std::make_pair(key.getExpiresAt(), std::move(key)));
}
if (_internalKeysCache.empty()) {
return {ErrorCodes::KeyNotFound, "No keys found after refresh"};
}
return _internalKeysCache.crbegin()->second;
}
Status KeysCollectionCache::_refreshExternalKeys(OperationContext* opCtx) {
decltype(_externalKeysCache)::size_type originalSize = 0;
{
stdx::lock_guard<Latch> lk(_cacheMutex);
originalSize = _externalKeysCache.size();
}
auto refreshStatus = _client->getAllExternalKeys(opCtx, _purpose);
if (!refreshStatus.isOK()) {
return refreshStatus.getStatus();
}
auto& newKeys = refreshStatus.getValue();
std::multimap<long long, ExternalKeysCollectionDocument> newExternalKeysCache;
for (auto&& key : newKeys) {
newExternalKeysCache.emplace(key.getKeyId(), std::move(key));
}
stdx::lock_guard<Latch> lk(_cacheMutex);
if (originalSize > _externalKeysCache.size()) {
// _externalKeysCache cleared while we were getting the new keys, just return so the next
// refresh will populate it properly.
return Status::OK();
}
// Replace the cached keys with the newly loaded ones. Note because all external keys are loaded
// when refreshing them, this will remove keys that have been deleted from the collection.
std::swap(_externalKeysCache, newExternalKeysCache);
return Status::OK();
}
StatusWith<KeysCollectionDocument> KeysCollectionCache::getInternalKeyById(
long long keyId, const LogicalTime& forThisTime) {
stdx::lock_guard<Latch> lk(_cacheMutex);
for (auto iter = _internalKeysCache.lower_bound(forThisTime); iter != _internalKeysCache.cend();
++iter) {
if (iter->second.getKeyId() == keyId) {
return iter->second;
}
}
return {ErrorCodes::KeyNotFound,
str::stream() << "Cache Reader No internal keys found for " << _purpose
<< " that is valid for time: " << forThisTime.toString()
<< " with id: " << keyId};
}
StatusWith<std::vector<ExternalKeysCollectionDocument>> KeysCollectionCache::getExternalKeysById(
long long keyId, const LogicalTime& forThisTime) {
stdx::lock_guard<Latch> lk(_cacheMutex);
std::vector<ExternalKeysCollectionDocument> keys;
if (_externalKeysCache.empty()) {
return {ErrorCodes::KeyNotFound,
str::stream() << "Cache Reader No external keys found for " << _purpose
<< " with id: " << keyId};
}
auto keysRange = _externalKeysCache.equal_range(keyId);
for (auto keyIter = keysRange.first; keyIter != keysRange.second; keyIter++) {
auto key = keyIter->second;
if (key.getExpiresAt() > forThisTime) {
keys.push_back(key);
}
}
if (keys.empty()) {
return {ErrorCodes::KeyNotFound,
str::stream() << "Cache Reader No external keys found for " << _purpose
<< " that is valid for time: " << forThisTime.toString()
<< " with id: " << keyId};
}
return std::move(keys);
}
StatusWith<KeysCollectionDocument> KeysCollectionCache::getInternalKey(
const LogicalTime& forThisTime) {
stdx::lock_guard<Latch> lk(_cacheMutex);
auto iter = _internalKeysCache.upper_bound(forThisTime);
if (iter == _internalKeysCache.cend()) {
return {ErrorCodes::KeyNotFound,
str::stream() << "No key found that is valid for " << forThisTime.toString()};
}
return iter->second;
}
void KeysCollectionCache::resetCache() {
// Refreshes try to use majority read concern, but if the client can't support that then any
// cached keys may have been rolled back and should be cleared.
if (_client->mustUseLocalReads()) {
stdx::lock_guard<Latch> lk(_cacheMutex);
_internalKeysCache.clear();
_externalKeysCache.clear();
}
}
void KeysCollectionCache::cacheExternalKey(ExternalKeysCollectionDocument key) {
stdx::lock_guard<Latch> lk(_cacheMutex);
_externalKeysCache.emplace(key.getKeyId(), std::move(key));
}
} // namespace mongo
|
