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author | Judah Schvimer <judah@mongodb.com> | 2017-01-18 11:43:30 -0500 |
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committer | Judah Schvimer <judah@mongodb.com> | 2017-01-20 09:35:28 -0500 |
commit | 0f4d520a648a11b612c67b1d983f748a10a97fb1 (patch) | |
tree | e5fd16d314a475e474fae6ebc1020abbceada429 | |
parent | ccc8b5f73611f54d6f4e5f082e67e99dd17b74db (diff) | |
download | mongo-0f4d520a648a11b612c67b1d983f748a10a97fb1.tar.gz |
SERVER-27157 replSetRequestVotes should only store votes with higher terms
(cherry picked from commit 2369c1863931e5c7f671c33421416c9580f80626)
-rw-r--r-- | src/mongo/db/repl/replication_coordinator_external_state_impl.cpp | 19 | ||||
-rw-r--r-- | src/mongo/dbtests/SConscript | 1 | ||||
-rw-r--r-- | src/mongo/dbtests/replica_set_tests.cpp | 135 |
3 files changed, 154 insertions, 1 deletions
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp index 9ee30a8ace7..c439f0d4a80 100644 --- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp +++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp @@ -545,7 +545,24 @@ Status ReplicationCoordinatorExternalStateImpl::storeLocalLastVoteDocument( MONGO_WRITE_CONFLICT_RETRY_LOOP_BEGIN { ScopedTransaction transaction(txn, MODE_IX); Lock::DBLock dbWriteLock(txn->lockState(), lastVoteDatabaseName, MODE_X); - Helpers::putSingleton(txn, lastVoteCollectionName, lastVoteObj); + + // If there is no last vote document, we want to store one. Otherwise, we only want to + // replace it if the new last vote document would have a higher term. We both check + // the term of the current last vote document and insert the new document under the + // DBLock to synchronize the two operations. + BSONObj result; + bool exists = Helpers::getSingleton(txn, lastVoteCollectionName, result); + if (!exists) { + Helpers::putSingleton(txn, lastVoteCollectionName, lastVoteObj); + } else { + StatusWith<LastVote> oldLastVoteDoc = LastVote::readFromLastVote(result); + if (!oldLastVoteDoc.isOK()) { + return oldLastVoteDoc.getStatus(); + } + if (lastVote.getTerm() > oldLastVoteDoc.getValue().getTerm()) { + Helpers::putSingleton(txn, lastVoteCollectionName, lastVoteObj); + } + } } MONGO_WRITE_CONFLICT_RETRY_LOOP_END( txn, "save replica set lastVote", lastVoteCollectionName); diff --git a/src/mongo/dbtests/SConscript b/src/mongo/dbtests/SConscript index f67d20040d3..b82f16fdb15 100644 --- a/src/mongo/dbtests/SConscript +++ b/src/mongo/dbtests/SConscript @@ -102,6 +102,7 @@ dbtest = env.Program( 'query_stage_update.cpp', 'querytests.cpp', 'replica_set_monitor_test.cpp', + 'replica_set_tests.cpp', 'repltests.cpp', 'rollbacktests.cpp', 'socktests.cpp', diff --git a/src/mongo/dbtests/replica_set_tests.cpp b/src/mongo/dbtests/replica_set_tests.cpp new file mode 100644 index 00000000000..f6cb5b11e21 --- /dev/null +++ b/src/mongo/dbtests/replica_set_tests.cpp @@ -0,0 +1,135 @@ +/** + * Copyright (C) 2017 MongoDB 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. + */ + +#include "mongo/platform/basic.h" + +#include "mongo/db/client.h" +#include "mongo/db/dbdirectclient.h" +#include "mongo/db/repl/last_vote.h" +#include "mongo/db/repl/replication_coordinator_external_state_impl.h" +#include "mongo/db/repl/storage_interface_mock.h" +#include "mongo/db/service_context.h" +#include "mongo/unittest/unittest.h" + +namespace mongo { +namespace { + +ServiceContext::UniqueOperationContext makeOpCtx() { + return cc().makeOperationContext(); +} + +class ReplicaSetTest : public mongo::unittest::Test { +protected: + void setUp() { + auto txn = makeOpCtx(); + _storageInterface = stdx::make_unique<repl::StorageInterfaceMock>(); + _replCoordExternalState.reset( + new repl::ReplicationCoordinatorExternalStateImpl(_storageInterface.get())); + } + + void tearDown() { + auto txn = makeOpCtx(); + DBDirectClient client(txn.get()); + client.dropCollection("local.replset.election"); + + _replCoordExternalState.reset(); + _storageInterface.reset(); + } + + repl::ReplicationCoordinatorExternalStateImpl* getReplCoordExternalState() { + return _replCoordExternalState.get(); + } + + repl::StorageInterface& getStorageInterface() { + return *_storageInterface; + } + +private: + std::unique_ptr<repl::ReplicationCoordinatorExternalStateImpl> _replCoordExternalState; + std::unique_ptr<repl::StorageInterface> _storageInterface; +}; + +TEST_F(ReplicaSetTest, ReplCoordExternalStateStoresLastVoteWithNewTerm) { + auto txn = makeOpCtx(); + auto replCoordExternalState = getReplCoordExternalState(); + + replCoordExternalState->storeLocalLastVoteDocument(txn.get(), repl::LastVote{2, 1}); + + auto lastVote = replCoordExternalState->loadLocalLastVoteDocument(txn.get()); + ASSERT_OK(lastVote.getStatus()); + ASSERT_EQ(lastVote.getValue().getTerm(), 2); + ASSERT_EQ(lastVote.getValue().getCandidateIndex(), 1); + + replCoordExternalState->storeLocalLastVoteDocument(txn.get(), repl::LastVote{3, 1}); + + lastVote = replCoordExternalState->loadLocalLastVoteDocument(txn.get()); + ASSERT_OK(lastVote.getStatus()); + ASSERT_EQ(lastVote.getValue().getTerm(), 3); + ASSERT_EQ(lastVote.getValue().getCandidateIndex(), 1); +} + +TEST_F(ReplicaSetTest, ReplCoordExternalStateDoesNotStoreLastVoteWithOldTerm) { + auto txn = makeOpCtx(); + auto replCoordExternalState = getReplCoordExternalState(); + + replCoordExternalState->storeLocalLastVoteDocument(txn.get(), repl::LastVote{2, 1}); + + auto lastVote = replCoordExternalState->loadLocalLastVoteDocument(txn.get()); + ASSERT_OK(lastVote.getStatus()); + ASSERT_EQ(lastVote.getValue().getTerm(), 2); + ASSERT_EQ(lastVote.getValue().getCandidateIndex(), 1); + + replCoordExternalState->storeLocalLastVoteDocument(txn.get(), repl::LastVote{1, 1}); + + lastVote = replCoordExternalState->loadLocalLastVoteDocument(txn.get()); + ASSERT_OK(lastVote.getStatus()); + ASSERT_EQ(lastVote.getValue().getTerm(), 2); + ASSERT_EQ(lastVote.getValue().getCandidateIndex(), 1); +} + +TEST_F(ReplicaSetTest, ReplCoordExternalStateDoesNotStoreLastVoteWithEqualTerm) { + auto txn = makeOpCtx(); + auto replCoordExternalState = getReplCoordExternalState(); + + replCoordExternalState->storeLocalLastVoteDocument(txn.get(), repl::LastVote{2, 1}); + + auto lastVote = replCoordExternalState->loadLocalLastVoteDocument(txn.get()); + ASSERT_OK(lastVote.getStatus()); + ASSERT_EQ(lastVote.getValue().getTerm(), 2); + ASSERT_EQ(lastVote.getValue().getCandidateIndex(), 1); + + replCoordExternalState->storeLocalLastVoteDocument(txn.get(), repl::LastVote{2, 2}); + + lastVote = replCoordExternalState->loadLocalLastVoteDocument(txn.get()); + ASSERT_OK(lastVote.getStatus()); + ASSERT_EQ(lastVote.getValue().getTerm(), 2); + ASSERT_EQ(lastVote.getValue().getCandidateIndex(), 1); +} + +} // namespace +} // namespace mongo |