SERVER-18385 add DryRun support to RequestVotes, VoteRequester, and TopologyCoordinator

9 files changed, 342 insertions, 6 deletions

diff --git a/src/mongo/db/repl/repl_set_request_votes_args.cpp b/src/mongo/db/repl/repl_set_request_votes_args.cpp
index da8123ab9f6..8c29e37b29d 100644
--- a/src/mongo/db/repl/repl_set_request_votes_args.cpp
+++ b/src/mongo/db/repl/repl_set_request_votes_args.cpp
@@ -39,6 +39,7 @@ namespace {
     const std::string kCandidateIdFieldName = "candidateId";
     const std::string kCommandName = "replSetRequestVotes";
     const std::string kConfigVersionFieldName = "configVersion";
+    const std::string kDryRunFieldName = "dryRun";
     const std::string kLastCommittedOpFieldName = "lastCommittedOp";
     const std::string kOkFieldName = "ok";
     const std::string kOpTimeFieldName = "ts";
@@ -51,6 +52,7 @@ namespace {
         kCandidateIdFieldName,
         kCommandName,
         kConfigVersionFieldName,
+        kDryRunFieldName,
         kLastCommittedOpFieldName,
         kOpTimeFieldName,
         kSetNameFieldName,
@@ -90,6 +92,10 @@ namespace {
         if (!status.isOK())
             return status;
 
+        status = bsonExtractBooleanField(argsObj, kDryRunFieldName, &_dryRun);
+        if (!status.isOK())
+            return status;
+
         // extracting the lastCommittedOp is a bit of a process
         BSONObj lastCommittedOp = argsObj[kLastCommittedOpFieldName].Obj();
         Timestamp ts;
@@ -126,9 +132,14 @@ namespace {
         return _lastCommittedOp;
     }
 
+    bool ReplSetRequestVotesArgs::isADryRun() const {
+        return _dryRun;
+    }
+
     void ReplSetRequestVotesArgs::addToBSON(BSONObjBuilder* builder) const {
         builder->append(kCommandName, 1);
         builder->append(kSetNameFieldName, _setName);
+        builder->append(kDryRunFieldName, _dryRun);
         builder->append(kTermFieldName, _term);
         builder->appendIntOrLL(kCandidateIdFieldName, _candidateId);
         builder->appendIntOrLL(kConfigVersionFieldName, _cfgver);
diff --git a/src/mongo/db/repl/repl_set_request_votes_args.h b/src/mongo/db/repl/repl_set_request_votes_args.h
index f7152fe838e..a0f2dc2157b 100644
--- a/src/mongo/db/repl/repl_set_request_votes_args.h
+++ b/src/mongo/db/repl/repl_set_request_votes_args.h
@@ -47,6 +47,7 @@ namespace repl {
         long long getCandidateId() const;
         long long getConfigVersion() const;
         OpTime getLastCommittedOp() const;
+        bool isADryRun() const;
 
         void addToBSON(BSONObjBuilder* builder) const;
 
@@ -56,6 +57,7 @@ namespace repl {
         long long _candidateId = -1; // replSet id of the member who sent the replSetRequestVotesCmd
         long long _cfgver = -1; // replSet config version known to the command issuer
         OpTime _lastCommittedOp; // The last known committed op of the command issuer 
+        bool _dryRun = false; // Indicates this is a pre-election check when true
     };
 
     class ReplSetRequestVotesResponse {
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 23e15702299..a225b7f454d 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -2563,7 +2563,9 @@ namespace {
             return {ErrorCodes::BadValue, "not using election protocol v1"};
         }
 
-        updateTerm(args.getTerm());
+        if (!args.isADryRun()) {
+            updateTerm(args.getTerm());
+        }
 
         Status result{ErrorCodes::InternalError, "didn't set status in processReplSetRequestVotes"};
         CBHStatus cbh = _replExecutor.scheduleWork(
diff --git a/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp b/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp
index 25559eb5987..d774b1ee820 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_elect_v1.cpp
@@ -147,6 +147,7 @@ namespace {
                 _rsConfig,
                 _rsConfig.getMemberAt(_selfIndex).getId(),
                 _topCoord->getTerm(),
+                false, // TODO(dannenberg): make this the second election stage by adding a dryrun
                 getMyLastOptime(),
                 stdx::bind(&ReplicationCoordinatorImpl::_onVoteRequestComplete, this));
         if (nextPhaseEvh.getStatus() == ErrorCodes::ShutdownInProgress) {
diff --git a/src/mongo/db/repl/topology_coordinator_impl.cpp b/src/mongo/db/repl/topology_coordinator_impl.cpp
index f600e266001..08d7ac7198c 100644
--- a/src/mongo/db/repl/topology_coordinator_impl.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl.cpp
@@ -2272,13 +2272,15 @@ namespace {
             response->setVoteGranted(false);
             response->setReason("candidate's data is staler than mine");
         }
-        else if (_lastVote.getTerm() == args.getTerm()) {
+        else if (!args.isADryRun() && _lastVote.getTerm() == args.getTerm()) {
             response->setVoteGranted(false);
             response->setReason("already voted for another candidate this term");
         }
         else {
-            _lastVote.setTerm(args.getTerm());
-            _lastVote.setCandidateId(args.getCandidateId());
+            if (!args.isADryRun()) {
+                _lastVote.setTerm(args.getTerm());
+                _lastVote.setCandidateId(args.getCandidateId());
+            }
             response->setVoteGranted(true);
         }
 
diff --git a/src/mongo/db/repl/topology_coordinator_impl_test.cpp b/src/mongo/db/repl/topology_coordinator_impl_test.cpp
index 49179bd4f49..7378feb4067 100644
--- a/src/mongo/db/repl/topology_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/topology_coordinator_impl_test.cpp
@@ -4600,6 +4600,83 @@ namespace {
     
     }
 
+    TEST_F(TopoCoordTest, ProcessRequestVotesDryRunsDoNotDisallowFutureRequestVotes) {
+        updateConfig(BSON("_id" << "rs0" <<
+                          "version" << 1 <<
+                          "members" << BSON_ARRAY(
+                              BSON("_id" << 10 << "host" << "hself") <<
+                              BSON("_id" << 20 << "host" << "h2") <<
+                              BSON("_id" << 30 << "host" << "h3"))),
+                     0);
+        setSelfMemberState(MemberState::RS_SECONDARY);
+
+        // dry run
+        ReplSetRequestVotesArgs args;
+        args.initialize(BSON("replSetRequestVotes" << 1
+                          << "setName" << "rs0"
+                          << "dryRun" << true
+                          << "term" << 1LL
+                          << "candidateId" << 10LL
+                          << "configVersion" << 1LL
+                          << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                     << "term" << 0LL)));
+        ReplSetRequestVotesResponse response;
+        OpTime lastAppliedOpTime;
+
+        getTopoCoord().processReplSetRequestVotes(args, &response, lastAppliedOpTime);
+        ASSERT_EQUALS("", response.getReason());
+        ASSERT_TRUE(response.getVoteGranted());
+    
+        // second dry run fine
+        ReplSetRequestVotesArgs args2;
+        args2.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << true
+                           << "term" << 1LL
+                           << "candidateId" << 10LL
+                           << "configVersion" << 1LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response2;
+
+        getTopoCoord().processReplSetRequestVotes(args2, &response2, lastAppliedOpTime);
+        ASSERT_EQUALS("", response2.getReason());
+        ASSERT_TRUE(response2.getVoteGranted());
+    
+        // real request fine
+        ReplSetRequestVotesArgs args3;
+        args3.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << false
+                           << "term" << 1LL
+                           << "candidateId" << 10LL
+                           << "configVersion" << 1LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response3;
+
+        getTopoCoord().processReplSetRequestVotes(args3, &response3, lastAppliedOpTime);
+        ASSERT_EQUALS("", response3.getReason());
+        ASSERT_TRUE(response3.getVoteGranted());
+
+        // dry post real, fails
+        ReplSetRequestVotesArgs args4;
+        args4.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << false
+                           << "term" << 1LL
+                           << "candidateId" << 10LL
+                           << "configVersion" << 1LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response4;
+
+        getTopoCoord().processReplSetRequestVotes(args4, &response4, lastAppliedOpTime);
+        ASSERT_EQUALS("already voted for another candidate this term", response4.getReason());
+        ASSERT_FALSE(response4.getVoteGranted());
+
+    }
+
     TEST_F(TopoCoordTest, ProcessRequestVotesBadCommands) {
         updateConfig(BSON("_id" << "rs0" <<
                           "version" << 1 <<
@@ -4685,6 +4762,123 @@ namespace {
         ASSERT_FALSE(response4.getVoteGranted());
     }
 
+    TEST_F(TopoCoordTest, ProcessRequestVotesBadCommandsDryRun) {
+        updateConfig(BSON("_id" << "rs0" <<
+                          "version" << 1 <<
+                          "members" << BSON_ARRAY(
+                              BSON("_id" << 10 << "host" << "hself") <<
+                              BSON("_id" << 20 << "host" << "h2") <<
+                              BSON("_id" << 30 << "host" << "h3"))),
+                     0);
+        setSelfMemberState(MemberState::RS_SECONDARY);
+        // set term to 1
+        ASSERT(getTopoCoord().updateTerm(1));
+        // and make sure we voted in term 1
+        ReplSetRequestVotesArgs argsForRealVote;
+        argsForRealVote.initialize(BSON("replSetRequestVotes" << 1
+                                     << "setName" << "rs0"
+                                     << "term" << 1LL
+                                     << "candidateId" << 10LL
+                                     << "configVersion" << 1LL
+                                     << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                                 << "term" << 0LL)));
+        ReplSetRequestVotesResponse responseForRealVote;
+        OpTime lastAppliedOpTime;
+
+        getTopoCoord().processReplSetRequestVotes(argsForRealVote,
+                                                  &responseForRealVote,
+                                                  lastAppliedOpTime);
+        ASSERT_EQUALS("", responseForRealVote.getReason());
+        ASSERT_TRUE(responseForRealVote.getVoteGranted());
+    
+
+        // mismatched setName
+        ReplSetRequestVotesArgs args;
+        args.initialize(BSON("replSetRequestVotes" << 1
+                          << "setName" << "wrongName"
+                          << "dryRun" << true
+                          << "term" << 2LL
+                          << "candidateId" << 10LL
+                          << "configVersion" << 1LL
+                          << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                     << "term" << 0LL)));
+        ReplSetRequestVotesResponse response;
+
+        getTopoCoord().processReplSetRequestVotes(args, &response, lastAppliedOpTime);
+        ASSERT_EQUALS("candidate's set name differs from mine", response.getReason());
+        ASSERT_EQUALS(1, response.getTerm());
+        ASSERT_FALSE(response.getVoteGranted());
+    
+        // mismatched configVersion
+        ReplSetRequestVotesArgs args2;
+        args2.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << true
+                           << "term" << 2LL
+                           << "candidateId" << 20LL
+                           << "configVersion" << 0LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response2;
+
+        getTopoCoord().processReplSetRequestVotes(args2, &response2, lastAppliedOpTime);
+        ASSERT_EQUALS("candidate's config version differs from mine", response2.getReason());
+        ASSERT_EQUALS(1, response2.getTerm());
+        ASSERT_FALSE(response2.getVoteGranted());
+    
+        // stale term
+        ReplSetRequestVotesArgs args3;
+        args3.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << true
+                           << "term" << 0LL
+                           << "candidateId" << 20LL
+                           << "configVersion" << 1LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response3;
+
+        getTopoCoord().processReplSetRequestVotes(args3, &response3, lastAppliedOpTime);
+        ASSERT_EQUALS("candidate's term is lower than mine", response3.getReason());
+        ASSERT_EQUALS(1, response3.getTerm());
+        ASSERT_FALSE(response3.getVoteGranted());
+    
+        // repeat term
+        ReplSetRequestVotesArgs args4;
+        args4.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << true
+                           << "term" << 1LL
+                           << "candidateId" << 20LL
+                           << "configVersion" << 1LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response4;
+
+        getTopoCoord().processReplSetRequestVotes(args4, &response4, lastAppliedOpTime);
+        ASSERT_EQUALS("", response4.getReason());
+        ASSERT_EQUALS(1, response4.getTerm());
+        ASSERT_TRUE(response4.getVoteGranted());
+    
+        // stale OpTime
+        ReplSetRequestVotesArgs args5;
+        args5.initialize(BSON("replSetRequestVotes" << 1
+                           << "setName" << "rs0"
+                           << "dryRun" << true
+                           << "term" << 3LL
+                           << "candidateId" << 20LL
+                           << "configVersion" << 1LL
+                           << "lastCommittedOp" << BSON ("ts" << Timestamp(10, 0)
+                                                      << "term" << 0LL)));
+        ReplSetRequestVotesResponse response5;
+        OpTime lastAppliedOpTime2 = {Timestamp(20, 0), 0};
+
+        getTopoCoord().processReplSetRequestVotes(args5, &response5, lastAppliedOpTime2);
+        ASSERT_EQUALS("candidate's data is staler than mine", response5.getReason());
+        ASSERT_EQUALS(1, response5.getTerm());
+        ASSERT_FALSE(response5.getVoteGranted());
+    }
+
     TEST_F(TopoCoordTest, ProcessDeclareElectionWinner) {
         updateConfig(BSON("_id" << "rs0" <<
                           "version" << 1 <<
diff --git a/src/mongo/db/repl/vote_requester.cpp b/src/mongo/db/repl/vote_requester.cpp
index 5c51df02eb1..81691edf5d7 100644
--- a/src/mongo/db/repl/vote_requester.cpp
+++ b/src/mongo/db/repl/vote_requester.cpp
@@ -45,10 +45,12 @@ namespace repl {
     VoteRequester::Algorithm::Algorithm(const ReplicaSetConfig& rsConfig,
                                         long long candidateId,
                                         long long term,
+                                        bool dryRun,
                                         OpTime lastOplogEntry) :
             _rsConfig(rsConfig),
             _candidateId(candidateId),
             _term(term),
+            _dryRun(dryRun),
             _lastOplogEntry(lastOplogEntry) {
 
         // populate targets with all voting members that aren't this node
@@ -66,6 +68,7 @@ namespace repl {
         BSONObjBuilder requestVotesCmdBuilder;
         requestVotesCmdBuilder.append("replSetRequestVotes", 1);
         requestVotesCmdBuilder.append("setName", _rsConfig.getReplSetName());
+        requestVotesCmdBuilder.append("dryRun", _dryRun);
         requestVotesCmdBuilder.append("term", _term);
         requestVotesCmdBuilder.append("candidateId", _candidateId);
         requestVotesCmdBuilder.append("configVersion", _rsConfig.getConfigVersion());
@@ -112,7 +115,6 @@ namespace repl {
                 _staleTerm = true;
             }
         }
-
     }
 
     bool VoteRequester::Algorithm::hasReceivedSufficientResponses() const {
@@ -141,12 +143,14 @@ namespace repl {
             const ReplicaSetConfig& rsConfig,
             long long candidateId,
             long long term,
+            bool dryRun,
             OpTime lastOplogEntry,
             const stdx::function<void ()>& onCompletion) {
 
         _algorithm.reset(new Algorithm(rsConfig,
                                        candidateId,
                                        term,
+                                       dryRun,
                                        lastOplogEntry));
         _runner.reset(new ScatterGatherRunner(_algorithm.get()));
         return _runner->start(executor, onCompletion);
diff --git a/src/mongo/db/repl/vote_requester.h b/src/mongo/db/repl/vote_requester.h
index a1659349bea..a5102192ebd 100644
--- a/src/mongo/db/repl/vote_requester.h
+++ b/src/mongo/db/repl/vote_requester.h
@@ -63,6 +63,7 @@ namespace repl {
             Algorithm(const ReplicaSetConfig& rsConfig,
                       long long candidateId,
                       long long term,
+                      bool dryRun,
                       OpTime lastOplogEntry);
             virtual ~Algorithm();
             virtual std::vector<RemoteCommandRequest> getRequests() const;
@@ -82,6 +83,7 @@ namespace repl {
             const ReplicaSetConfig _rsConfig;
             const long long _candidateId;
             const long long _term;
+            bool _dryRun = false; // this bool indicates this is a mock election when true
             const OpTime _lastOplogEntry;
             std::vector<HostAndPort> _targets;
             bool _staleTerm = false;
@@ -106,6 +108,7 @@ namespace repl {
             const ReplicaSetConfig& rsConfig,
             long long candidateId,
             long long term,
+            bool dryRun,
             OpTime lastOplogEntry,
             const stdx::function<void ()>& onCompletion = stdx::function<void ()>());
 
diff --git a/src/mongo/db/repl/vote_requester_test.cpp b/src/mongo/db/repl/vote_requester_test.cpp
index 90d0843d843..d5b9d9ce3d5 100644
--- a/src/mongo/db/repl/vote_requester_test.cpp
+++ b/src/mongo/db/repl/vote_requester_test.cpp
@@ -75,6 +75,7 @@ namespace {
             _requester.reset(new VoteRequester::Algorithm(config,
                                                           candidateId,
                                                           term,
+                                                          false, // not a dryRun
                                                           lastOplogEntry));
         }
 
@@ -173,10 +174,36 @@ namespace {
                                                                  Milliseconds(10)));
         }
 
-    private:
         std::unique_ptr<VoteRequester::Algorithm> _requester;
     };
 
+    class VoteRequesterDryRunTest : public VoteRequesterTest {
+    public:
+        virtual void setUp() {
+            ReplicaSetConfig config;
+            ASSERT_OK(config.initialize(
+                BSON("_id" << "rs0" <<
+                     "version" << 2 <<
+                     "members" << BSON_ARRAY(
+                         BSON("_id" << 0 << "host" << "host0") <<
+                         BSON("_id" << 1 << "host" << "host1") <<
+                         BSON("_id" << 2 << "host" << "host2") <<
+                         BSON("_id" << 3 << "host" << "host3" << "votes" << 0) <<
+                         BSON("_id" << 4 << "host" << "host4" << "votes" << 0)))));
+            ASSERT_OK(config.validate());
+            long long candidateId = 0;
+            long long term = 2;
+            OpTime lastOplogEntry = OpTime(Timestamp(999,0), 1);
+
+            _requester.reset(new VoteRequester::Algorithm(config,
+                                                          candidateId,
+                                                          term,
+                                                          true, // dryRun
+                                                          lastOplogEntry));
+        }
+
+    };
+
     TEST_F(VoteRequesterTest, ImmediateGoodResponseWinElection) {
         ASSERT_FALSE(hasReceivedSufficientResponses());
         processResponse(requestFrom("host1"), votedYes());
@@ -267,6 +294,96 @@ namespace {
         stopCapturingLogMessages();
     }
 
+    TEST_F(VoteRequesterDryRunTest, ImmediateGoodResponseWinElection) {
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedYes());
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::SuccessfullyElected, getResult());
+    }
+
+    TEST_F(VoteRequesterDryRunTest, BadConfigVersionWinElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedNoBecauseConfigVersionDoesNotMatch());
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got no vote from host1"));
+        processResponse(requestFrom("host2"), votedYes());
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::SuccessfullyElected, getResult());
+        stopCapturingLogMessages();
+    }
+
+    TEST_F(VoteRequesterDryRunTest, SetNameDiffersWinElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedNoBecauseSetNameDiffers());
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got no vote from host1"));
+        processResponse(requestFrom("host2"), votedYes());
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::SuccessfullyElected, getResult());
+        stopCapturingLogMessages();
+    }
+
+    TEST_F(VoteRequesterDryRunTest, LastOpTimeIsGreaterWinElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedNoBecauseLastOpTimeIsGreater());
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got no vote from host1"));
+        processResponse(requestFrom("host2"), votedYes());
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::SuccessfullyElected, getResult());
+        stopCapturingLogMessages();
+    }
+
+    TEST_F(VoteRequesterDryRunTest, FailedToContactWinElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), badResponseStatus());
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got failed response from host1"));
+        processResponse(requestFrom("host2"), votedYes());
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::SuccessfullyElected, getResult());
+        stopCapturingLogMessages();
+    }
+
+    TEST_F(VoteRequesterDryRunTest, AlreadyVotedWinElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedNoBecauseAlreadyVoted());
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got no vote from host1"));
+        processResponse(requestFrom("host2"), votedYes());
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::SuccessfullyElected, getResult());
+        stopCapturingLogMessages();
+    }
+
+    TEST_F(VoteRequesterDryRunTest, StaleTermLoseElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedNoBecauseTermIsGreater());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got no vote from host1"));
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::StaleTerm, getResult());
+        stopCapturingLogMessages();
+    }
+
+    TEST_F(VoteRequesterDryRunTest, NotEnoughVotesLoseElection) {
+        startCapturingLogMessages();
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        processResponse(requestFrom("host1"), votedNoBecauseSetNameDiffers());
+        ASSERT_FALSE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got no vote from host1"));
+        processResponse(requestFrom("host2"), badResponseStatus());
+        ASSERT_EQUALS(1, countLogLinesContaining("Got failed response from host2"));
+        ASSERT_TRUE(hasReceivedSufficientResponses());
+        ASSERT_EQUALS(VoteRequester::InsufficientVotes, getResult());
+        stopCapturingLogMessages();
+    }
+
 }  // namespace
 }  // namespace repl
 }  // namespace mongo