Revert "SERVER-26683 Log reason for marking repl hosts as failed in the RSM"

This reverts commit 80d6ca07522fce27f9559007791ebe4a1afe0866.

22 files changed, 207 insertions, 242 deletions

diff --git a/src/mongo/client/connpool.h b/src/mongo/client/connpool.h
index 509965971ff..586f1958319 100644
--- a/src/mongo/client/connpool.h
+++ b/src/mongo/client/connpool.h
@@ -51,8 +51,6 @@ struct ConnectionPoolStats;
  * thread safety is handled by DBConnectionPool
  */
 class PoolForHost {
-    MONGO_DISALLOW_COPYING(PoolForHost);
-
 public:
     // Sentinel value indicating pool has no cleanup limit
     static const int kPoolSizeUnlimited;
@@ -64,6 +62,16 @@ public:
           _maxPoolSize(kPoolSizeUnlimited),
           _checkedOut(0) {}
 
+    PoolForHost(const PoolForHost& other)
+        : _created(other._created),
+          _minValidCreationTimeMicroSec(other._minValidCreationTimeMicroSec),
+          _type(other._type),
+          _maxPoolSize(other._maxPoolSize),
+          _checkedOut(other._checkedOut) {
+        verify(_created == 0);
+        verify(other._pool.size() == 0);
+    }
+
     ~PoolForHost();
 
     /**
diff --git a/src/mongo/client/dbclient.cpp b/src/mongo/client/dbclient.cpp
index a2aff7de7b1..d8199e3d315 100644
--- a/src/mongo/client/dbclient.cpp
+++ b/src/mongo/client/dbclient.cpp
@@ -1432,13 +1432,12 @@ void DBClientConnection::handleNotMasterResponse(const BSONElement& elemToCheck)
         return;
     }
 
+    MONGO_LOG_COMPONENT(1, logger::LogComponent::kReplication)
+        << "got not master from: " << _serverAddress << " of repl set: " << _parentReplSetName;
+
     ReplicaSetMonitorPtr monitor = ReplicaSetMonitor::get(_parentReplSetName);
     if (monitor) {
-        monitor->failedHost(_serverAddress,
-                            {ErrorCodes::NotMaster,
-                             str::stream() << "got not master from: " << _serverAddress
-                                           << " of repl set: "
-                                           << _parentReplSetName});
+        monitor->failedHost(_serverAddress);
     }
 
     _failed = true;
diff --git a/src/mongo/client/dbclient_rs.cpp b/src/mongo/client/dbclient_rs.cpp
index 6261fa093c3..bd8ec5863c9 100644
--- a/src/mongo/client/dbclient_rs.cpp
+++ b/src/mongo/client/dbclient_rs.cpp
@@ -80,11 +80,6 @@ public:
 } _populateReadPrefSecOkCmdList;
 
 /**
- * Maximum number of retries to make for auto-retry logic when performing a slave ok operation.
- */
-const size_t MAX_RETRY = 3;
-
-/**
  * Extracts the read preference settings from the query document. Note that this method
  * assumes that the query is ok for secondaries so it defaults to
  * ReadPreference::SecondaryPreferred when nothing is specified. Supports the following
@@ -129,13 +124,13 @@ ReadPreferenceSetting* _extractReadPref(const BSONObj& query, int queryOptions)
         : mongo::ReadPreference::PrimaryOnly;
     return new ReadPreferenceSetting(pref, TagSet());
 }
-
 }  // namespace
 
 // --------------------------------
 // ----- DBClientReplicaSet ---------
 // --------------------------------
 
+const size_t DBClientReplicaSet::MAX_RETRY = 3;
 bool DBClientReplicaSet::_authPooledSecondaryConn = true;
 
 DBClientReplicaSet::DBClientReplicaSet(const string& name,
@@ -298,8 +293,7 @@ DBClientConnection* DBClientReplicaSet::checkMaster() {
         if (!_master->isFailed())
             return _master.get();
 
-        monitor->failedHost(
-            _masterHost, {ErrorCodes::fromInt(40332), "Last known master host cannot be reached"});
+        monitor->failedHost(_masterHost);
         h = monitor->getMasterOrUassert();  // old master failed, try again.
     }
 
@@ -321,11 +315,13 @@ DBClientConnection* DBClientReplicaSet::checkMaster() {
     }
 
     if (newConn == NULL || !errmsg.empty()) {
-        const std::string message = str::stream() << "can't connect to new replica set master ["
-                                                  << _masterHost.toString() << "]"
-                                                  << (errmsg.empty() ? "" : ", err: ") << errmsg;
-        monitor->failedHost(_masterHost, {ErrorCodes::fromInt(40333), message});
-        uasserted(ErrorCodes::FailedToSatisfyReadPreference, message);
+        monitor->failedHost(_masterHost);
+        uasserted(ErrorCodes::FailedToSatisfyReadPreference,
+                  str::stream() << "can't connect to new replica set master ["
+                                << _masterHost.toString()
+                                << "]"
+                                << (errmsg.empty() ? "" : ", err: ")
+                                << errmsg);
     }
 
     resetMaster();
@@ -353,8 +349,7 @@ bool DBClientReplicaSet::checkLastHost(const ReadPreferenceSetting* readPref) {
 
     // Make sure we don't think the host is down.
     if (_lastSlaveOkConn->isFailed() || !_getMonitor()->isHostUp(_lastSlaveOkHost)) {
-        _invalidateLastSlaveOkCache(
-            {ErrorCodes::fromInt(40334), "Last slave connection is no longer available"});
+        invalidateLastSlaveOkCache();
         return false;
     }
 
@@ -380,7 +375,7 @@ void DBClientReplicaSet::logoutAll(DBClientConnection* conn) {
             conn->logout(i->first, response);
         } catch (const UserException& ex) {
             warning() << "Failed to logout: " << conn->getServerAddress() << " on db: " << i->first
-                      << causedBy(redact(ex));
+                      << endl;
         }
     }
 }
@@ -453,13 +448,13 @@ void DBClientReplicaSet::_auth(const BSONObj& params) {
                 throw;
             }
 
-            const Status status = ex.toStatus();
-            lastNodeStatus = {status.code(),
-                              str::stream() << "can't authenticate against replica set node "
-                                            << _lastSlaveOkHost
-                                            << ": "
-                                            << status.reason()};
-            _invalidateLastSlaveOkCache(lastNodeStatus);
+            StringBuilder errMsgB;
+            errMsgB << "can't authenticate against replica set node "
+                    << _lastSlaveOkHost.toString();
+            lastNodeStatus = ex.toStatus(errMsgB.str());
+
+            LOG(1) << lastNodeStatus.reason() << endl;
+            invalidateLastSlaveOkCache();
         }
     }
 
@@ -542,12 +537,14 @@ unique_ptr<DBClientCursor> DBClientReplicaSet::query(const string& ns,
                     ns, query, nToReturn, nToSkip, fieldsToReturn, queryOptions, batchSize);
 
                 return checkSlaveQueryResult(std::move(cursor));
-            } catch (const DBException& ex) {
-                const Status status = ex.toStatus();
-                _invalidateLastSlaveOkCache(
-                    {status.code(),
-                     str::stream() << "can't query replica set node " << _lastSlaveOkHost << ": "
-                                   << status.reason()});
+            } catch (const DBException& dbExcep) {
+                StringBuilder errMsgBuilder;
+                errMsgBuilder << "can't query replica set node " << _lastSlaveOkHost.toString()
+                              << ": " << causedBy(redact(dbExcep));
+                lastNodeErrMsg = errMsgBuilder.str();
+
+                LOG(1) << lastNodeErrMsg << endl;
+                invalidateLastSlaveOkCache();
             }
         }
 
@@ -592,13 +589,14 @@ BSONObj DBClientReplicaSet::findOne(const string& ns,
                 }
 
                 return conn->findOne(ns, query, fieldsToReturn, queryOptions);
-            } catch (const DBException& ex) {
-                const Status status = ex.toStatus();
-                _invalidateLastSlaveOkCache({status.code(),
-                                             str::stream() << "can't findone replica set node "
-                                                           << _lastSlaveOkHost.toString()
-                                                           << ": "
-                                                           << status.reason()});
+            } catch (const DBException& dbExcep) {
+                StringBuilder errMsgBuilder;
+                errMsgBuilder << "can't findone replica set node " << _lastSlaveOkHost.toString()
+                              << ": " << causedBy(redact(dbExcep));
+                lastNodeErrMsg = errMsgBuilder.str();
+
+                LOG(1) << lastNodeErrMsg << endl;
+                invalidateLastSlaveOkCache();
             }
         }
 
@@ -625,11 +623,10 @@ void DBClientReplicaSet::killCursor(long long cursorID) {
 }
 
 void DBClientReplicaSet::isntMaster() {
-    // Can't use _getMonitor because that will create a new monitor from the cached seed if the
-    // monitor doesn't exist.
-    _rsm->failedHost(
-        _masterHost,
-        {ErrorCodes::NotMaster, str::stream() << "got not master for: " << _masterHost});
+    log() << "got not master for: " << _masterHost << endl;
+    // Can't use _getMonitor because that will create a new monitor from the cached seed if
+    // the monitor doesn't exist.
+    _rsm->failedHost(_masterHost);
 
     resetMaster();
 }
@@ -659,11 +656,9 @@ unique_ptr<DBClientCursor> DBClientReplicaSet::checkSlaveQueryResult(
 }
 
 void DBClientReplicaSet::isntSecondary() {
+    log() << "slave no longer has secondary status: " << _lastSlaveOkHost << endl;
     // Failover to next slave
-    _getMonitor()->failedHost(
-        _lastSlaveOkHost,
-        {ErrorCodes::NotMasterOrSecondary,
-         str::stream() << "slave no longer has secondary status: " << _lastSlaveOkHost});
+    _getMonitor()->failedHost(_lastSlaveOkHost);
 
     resetSlaveOkConn();
 }
@@ -779,13 +774,15 @@ void DBClientReplicaSet::say(Message& toSend, bool isRetry, string* actualServer
                     _lazyState._lastOp = lastOp;
                     _lazyState._secondaryQueryOk = true;
                     _lazyState._lastClient = conn;
-                } catch (const DBException& e) {
-                    const Status status = e.toStatus();
-                    _invalidateLastSlaveOkCache({status.code(),
-                                                 str::stream() << "can't callLazy replica set node "
-                                                               << _lastSlaveOkHost.toString()
-                                                               << ": "
-                                                               << status.reason()});
+                } catch (const DBException& DBExcep) {
+                    StringBuilder errMsgBuilder;
+                    errMsgBuilder << "can't callLazy replica set node "
+                                  << _lastSlaveOkHost.toString() << ": "
+                                  << causedBy(redact(DBExcep));
+                    lastNodeErrMsg = errMsgBuilder.str();
+
+                    LOG(1) << lastNodeErrMsg << endl;
+                    invalidateLastSlaveOkCache();
                     continue;
                 }
 
@@ -955,10 +952,10 @@ DBClientReplicaSet::runCommandWithMetadataAndTarget(StringData database,
             return std::make_tuple(
                 conn->runCommandWithMetadata(database, command, metadata, commandArgs), conn);
         } catch (const DBException& ex) {
-            _invalidateLastSlaveOkCache(ex.toStatus());
+            log() << exceptionToStatus();
+            invalidateLastSlaveOkCache();
         }
     }
-
     uasserted(ErrorCodes::NodeNotFound,
               str::stream() << "Could not satisfy $readPreference of '" << readPref.toBSON() << "' "
                             << "while attempting to run command "
@@ -1001,15 +998,14 @@ bool DBClientReplicaSet::call(Message& toSend,
                     }
 
                     return conn->call(toSend, response, assertOk, nullptr);
-                } catch (const DBException& ex) {
+                } catch (const DBException& dbExcep) {
+                    LOG(1) << "can't call replica set node " << _lastSlaveOkHost << ": "
+                           << causedBy(redact(dbExcep));
+
                     if (actualServer)
                         *actualServer = "";
 
-                    const Status status = ex.toStatus();
-                    _invalidateLastSlaveOkCache(
-                        {status.code(),
-                         str::stream() << "can't call replica set node " << _lastSlaveOkHost << ": "
-                                       << status.reason()});
+                    invalidateLastSlaveOkCache();
                 }
             }
 
@@ -1044,11 +1040,12 @@ bool DBClientReplicaSet::call(Message& toSend,
     return true;
 }
 
-void DBClientReplicaSet::_invalidateLastSlaveOkCache(const Status& status) {
-    // This is not wrapped in with if (_lastSlaveOkConn && _lastSlaveOkConn->isFailed()) because
-    // there are certain exceptions that will not make the connection be labeled as failed. For
-    // example, asserts 13079, 13080, 16386
-    _getMonitor()->failedHost(_lastSlaveOkHost, status);
+void DBClientReplicaSet::invalidateLastSlaveOkCache() {
+    /* This is not wrapped in with if (_lastSlaveOkConn && _lastSlaveOkConn->isFailed())
+     * because there are certain exceptions that will not make the connection be labeled
+     * as failed. For example, asserts 13079, 13080, 16386
+     */
+    _getMonitor()->failedHost(_lastSlaveOkHost);
     resetSlaveOkConn();
 }
 
diff --git a/src/mongo/client/dbclient_rs.h b/src/mongo/client/dbclient_rs.h
index 02e9db27f65..17f25904c25 100644
--- a/src/mongo/client/dbclient_rs.h
+++ b/src/mongo/client/dbclient_rs.h
@@ -269,10 +269,9 @@ private:
     bool checkLastHost(const ReadPreferenceSetting* readPref);
 
     /**
-     * Destroys all cached information about the last slaveOk operation and reports the host as
-     * failed in the replica set monitor with the specified 'status'.
+     * Destroys all cached information about the last slaveOk operation.
      */
-    void _invalidateLastSlaveOkCache(const Status& status);
+    void invalidateLastSlaveOkCache();
 
     void _authConnection(DBClientConnection* conn);
 
@@ -292,6 +291,12 @@ private:
      */
     void resetSlaveOkConn();
 
+    /**
+     * Maximum number of retries to make for auto-retry logic when performing a slave ok
+     * operation.
+     */
+    static const size_t MAX_RETRY;
+
     // TODO: remove this when processes other than mongos uses the driver version.
     static bool _authPooledSecondaryConn;
 
diff --git a/src/mongo/client/dbclient_rs_test.cpp b/src/mongo/client/dbclient_rs_test.cpp
index b900070e755..e101695cdc8 100644
--- a/src/mongo/client/dbclient_rs_test.cpp
+++ b/src/mongo/client/dbclient_rs_test.cpp
@@ -691,8 +691,7 @@ TEST_F(TaggedFiveMemberRS, ConnShouldNotPinIfHostMarkedAsFailed) {
     // This is the only difference from ConnShouldPinIfSameSettings which tests that we *do* pin
     // in if the host is still marked as up. Note that this only notifies the RSM, and does not
     // directly effect the DBClientRS.
-    ReplicaSetMonitor::get(replSet->getSetName())
-        ->failedHost(HostAndPort(dest), {ErrorCodes::InternalError, "Test error"});
+    ReplicaSetMonitor::get(replSet->getSetName())->failedHost(HostAndPort(dest));
 
     {
         Query query;
diff --git a/src/mongo/client/remote_command_targeter.h b/src/mongo/client/remote_command_targeter.h
index 98c6fa0c72c..ca751be0dec 100644
--- a/src/mongo/client/remote_command_targeter.h
+++ b/src/mongo/client/remote_command_targeter.h
@@ -93,18 +93,18 @@ public:
     }
 
     /**
-     * Reports to the targeter that a 'status' indicating a not master error was received when
-     * communicating with 'host', and so it should update its bookkeeping to avoid giving out the
-     * host again on a subsequent request for the primary.
+     * Reports to the targeter that a NotMaster response was received when communicating with
+     * "host', and so it should update its bookkeeping to avoid giving out the host again on a
+     * subsequent request for the primary.
      */
-    virtual void markHostNotMaster(const HostAndPort& host, const Status& status) = 0;
+    virtual void markHostNotMaster(const HostAndPort& host) = 0;
 
     /**
-     * Reports to the targeter that a 'status' indicating a network error was received when trying
-     * to communicate with 'host', and so it should update its bookkeeping to avoid giving out the
-     * host again on a subsequent request for the primary.
+     * Similar to markHostNotMaster(). Reports to the targeter that a HostUnreachable response was
+     * received when communicating with "host". The targeter should update its bookkeeping to avoid
+     * giving out the same host on a subsequent request.
      */
-    virtual void markHostUnreachable(const HostAndPort& host, const Status& status) = 0;
+    virtual void markHostUnreachable(const HostAndPort& host) = 0;
 
 protected:
     RemoteCommandTargeter() = default;
diff --git a/src/mongo/client/remote_command_targeter_factory_mock.cpp b/src/mongo/client/remote_command_targeter_factory_mock.cpp
index 41cf0949f61..3d30edf7a32 100644
--- a/src/mongo/client/remote_command_targeter_factory_mock.cpp
+++ b/src/mongo/client/remote_command_targeter_factory_mock.cpp
@@ -57,12 +57,12 @@ public:
         return _mock->findHostWithMaxWait(readPref, maxWait);
     }
 
-    void markHostNotMaster(const HostAndPort& host, const Status& status) override {
-        _mock->markHostNotMaster(host, status);
+    void markHostNotMaster(const HostAndPort& host) override {
+        _mock->markHostNotMaster(host);
     }
 
-    void markHostUnreachable(const HostAndPort& host, const Status& status) override {
-        _mock->markHostUnreachable(host, status);
+    void markHostUnreachable(const HostAndPort& host) override {
+        _mock->markHostUnreachable(host);
     }
 
 private:
diff --git a/src/mongo/client/remote_command_targeter_mock.cpp b/src/mongo/client/remote_command_targeter_mock.cpp
index b216a717a29..617efb699fc 100644
--- a/src/mongo/client/remote_command_targeter_mock.cpp
+++ b/src/mongo/client/remote_command_targeter_mock.cpp
@@ -63,10 +63,9 @@ StatusWith<HostAndPort> RemoteCommandTargeterMock::findHostWithMaxWait(
     return _findHostReturnValue;
 }
 
-void RemoteCommandTargeterMock::markHostNotMaster(const HostAndPort& host, const Status& status) {}
+void RemoteCommandTargeterMock::markHostNotMaster(const HostAndPort& host) {}
 
-void RemoteCommandTargeterMock::markHostUnreachable(const HostAndPort& host, const Status& status) {
-}
+void RemoteCommandTargeterMock::markHostUnreachable(const HostAndPort& host) {}
 
 void RemoteCommandTargeterMock::setConnectionStringReturnValue(const ConnectionString returnValue) {
     _connectionStringReturnValue = std::move(returnValue);
diff --git a/src/mongo/client/remote_command_targeter_mock.h b/src/mongo/client/remote_command_targeter_mock.h
index 23dbb92a6ba..6183a635f61 100644
--- a/src/mongo/client/remote_command_targeter_mock.h
+++ b/src/mongo/client/remote_command_targeter_mock.h
@@ -63,12 +63,12 @@ public:
     /**
      * No-op for the mock.
      */
-    void markHostNotMaster(const HostAndPort& host, const Status& status) override;
+    void markHostNotMaster(const HostAndPort& host) override;
 
     /**
      * No-op for the mock.
      */
-    void markHostUnreachable(const HostAndPort& host, const Status& status) override;
+    void markHostUnreachable(const HostAndPort& host) override;
 
     /**
      * Sets the return value for the next call to connectionString.
diff --git a/src/mongo/client/remote_command_targeter_rs.cpp b/src/mongo/client/remote_command_targeter_rs.cpp
index 59ae0d9cdbf..b389df23f0e 100644
--- a/src/mongo/client/remote_command_targeter_rs.cpp
+++ b/src/mongo/client/remote_command_targeter_rs.cpp
@@ -88,16 +88,16 @@ StatusWith<HostAndPort> RemoteCommandTargeterRS::findHost(OperationContext* txn,
     }
 }
 
-void RemoteCommandTargeterRS::markHostNotMaster(const HostAndPort& host, const Status& status) {
+void RemoteCommandTargeterRS::markHostNotMaster(const HostAndPort& host) {
     invariant(_rsMonitor);
 
-    _rsMonitor->failedHost(host, status);
+    _rsMonitor->failedHost(host);
 }
 
-void RemoteCommandTargeterRS::markHostUnreachable(const HostAndPort& host, const Status& status) {
+void RemoteCommandTargeterRS::markHostUnreachable(const HostAndPort& host) {
     invariant(_rsMonitor);
 
-    _rsMonitor->failedHost(host, status);
+    _rsMonitor->failedHost(host);
 }
 
 }  // namespace mongo
diff --git a/src/mongo/client/remote_command_targeter_rs.h b/src/mongo/client/remote_command_targeter_rs.h
index 7a8851c01ee..9917613834e 100644
--- a/src/mongo/client/remote_command_targeter_rs.h
+++ b/src/mongo/client/remote_command_targeter_rs.h
@@ -58,9 +58,9 @@ public:
     StatusWith<HostAndPort> findHostWithMaxWait(const ReadPreferenceSetting& readPref,
                                                 Milliseconds maxWait) override;
 
-    void markHostNotMaster(const HostAndPort& host, const Status& status) override;
+    void markHostNotMaster(const HostAndPort& host) override;
 
-    void markHostUnreachable(const HostAndPort& host, const Status& status) override;
+    void markHostUnreachable(const HostAndPort& host) override;
 
 private:
     // Name of the replica set which this targeter maintains
diff --git a/src/mongo/client/remote_command_targeter_standalone.cpp b/src/mongo/client/remote_command_targeter_standalone.cpp
index b44cb1b4c44..a5afaef951a 100644
--- a/src/mongo/client/remote_command_targeter_standalone.cpp
+++ b/src/mongo/client/remote_command_targeter_standalone.cpp
@@ -52,13 +52,11 @@ StatusWith<HostAndPort> RemoteCommandTargeterStandalone::findHost(
     return _hostAndPort;
 }
 
-void RemoteCommandTargeterStandalone::markHostNotMaster(const HostAndPort& host,
-                                                        const Status& status) {
+void RemoteCommandTargeterStandalone::markHostNotMaster(const HostAndPort& host) {
     dassert(host == _hostAndPort);
 }
 
-void RemoteCommandTargeterStandalone::markHostUnreachable(const HostAndPort& host,
-                                                          const Status& status) {
+void RemoteCommandTargeterStandalone::markHostUnreachable(const HostAndPort& host) {
     dassert(host == _hostAndPort);
 }
 
diff --git a/src/mongo/client/remote_command_targeter_standalone.h b/src/mongo/client/remote_command_targeter_standalone.h
index dd9e97a9df2..ab7ae099243 100644
--- a/src/mongo/client/remote_command_targeter_standalone.h
+++ b/src/mongo/client/remote_command_targeter_standalone.h
@@ -49,9 +49,9 @@ public:
     StatusWith<HostAndPort> findHostWithMaxWait(const ReadPreferenceSetting& readPref,
                                                 Milliseconds maxWait) override;
 
-    void markHostNotMaster(const HostAndPort& host, const Status& status) override;
+    void markHostNotMaster(const HostAndPort& host) override;
 
-    void markHostUnreachable(const HostAndPort& host, const Status& status) override;
+    void markHostUnreachable(const HostAndPort& host) override;
 
 private:
     const HostAndPort _hostAndPort;
diff --git a/src/mongo/client/replica_set_monitor.cpp b/src/mongo/client/replica_set_monitor.cpp
index d27cd68d162..60f58bab9f1 100644
--- a/src/mongo/client/replica_set_monitor.cpp
+++ b/src/mongo/client/replica_set_monitor.cpp
@@ -310,11 +310,11 @@ Refresher ReplicaSetMonitor::startOrContinueRefresh() {
     return out;
 }
 
-void ReplicaSetMonitor::failedHost(const HostAndPort& host, const Status& status) {
+void ReplicaSetMonitor::failedHost(const HostAndPort& host) {
     stdx::lock_guard<stdx::mutex> lk(_state->mutex);
     Node* node = _state->findNode(host);
     if (node)
-        node->markFailed(status);
+        node->markFailed();
     DEV _state->checkInvariants();
 }
 
@@ -545,10 +545,9 @@ void Refresher::receivedIsMaster(const HostAndPort& from,
     _scan->waitingFor.erase(from);
 
     const IsMasterReply reply(from, latencyMicros, replyObj);
-
     // Handle various failure cases
     if (!reply.ok) {
-        failedHost(from, {ErrorCodes::CommandFailed, "Failed to execute 'ismaster' command"});
+        failedHost(from);
         return;
     }
 
@@ -566,19 +565,17 @@ void Refresher::receivedIsMaster(const HostAndPort& from,
             warning() << "node: " << from << " isn't a part of set: " << _set->name
                       << " ismaster: " << replyObj;
         }
-
-        failedHost(from,
-                   {ErrorCodes::InconsistentReplicaSetNames,
-                    str::stream() << "Target replica set name " << reply.setName
-                                  << " does not match the monitored set name "
-                                  << _set->name});
+        failedHost(from);
         return;
     }
 
     if (reply.isMaster) {
-        Status status = receivedIsMasterFromMaster(from, reply);
-        if (!status.isOK()) {
-            failedHost(from, status);
+        if (!receivedIsMasterFromMaster(reply)) {
+            log() << "node " << from << " believes it is primary, but its election id of "
+                  << reply.electionId << " and config version of " << reply.configVersion
+                  << " is older than the most recent election id " << _set->maxElectionId
+                  << " and config version of " << _set->configVersion;
+            failedHost(from);
             return;
         }
     }
@@ -601,7 +598,7 @@ void Refresher::receivedIsMaster(const HostAndPort& from,
     DEV _set->checkInvariants();
 }
 
-void Refresher::failedHost(const HostAndPort& host, const Status& status) {
+void Refresher::failedHost(const HostAndPort& host) {
     _scan->waitingFor.erase(host);
 
     // Failed hosts can't pass criteria, so the only way they'd effect the _refreshUntilMatches
@@ -611,7 +608,7 @@ void Refresher::failedHost(const HostAndPort& host, const Status& status) {
 
     Node* node = _set->findNode(host);
     if (node)
-        node->markFailed(status);
+        node->markFailed();
 }
 
 ScanStatePtr Refresher::startNewScan(const SetState* set) {
@@ -649,18 +646,13 @@ ScanStatePtr Refresher::startNewScan(const SetState* set) {
     return scan;
 }
 
-Status Refresher::receivedIsMasterFromMaster(const HostAndPort& from, const IsMasterReply& reply) {
+bool Refresher::receivedIsMasterFromMaster(const IsMasterReply& reply) {
     invariant(reply.isMaster);
 
     // Reject if config version is older. This is for backwards compatibility with nodes in pv0
     // since they don't have the same ordering with pv1 electionId.
     if (reply.configVersion < _set->configVersion) {
-        return {ErrorCodes::NotMaster,
-                str::stream() << "Node " << from
-                              << " believes it is primary, but its config version "
-                              << reply.configVersion
-                              << " is older than the most recent config version "
-                              << _set->configVersion};
+        return false;
     }
 
     if (reply.electionId.isSet()) {
@@ -669,12 +661,7 @@ Status Refresher::receivedIsMasterFromMaster(const HostAndPort& from, const IsMa
         // because configVersion needs to be incremented whenever the protocol version is changed.
         if (reply.configVersion == _set->configVersion && _set->maxElectionId.isSet() &&
             _set->maxElectionId.compare(reply.electionId) > 0) {
-            return {ErrorCodes::NotMaster,
-                    str::stream() << "Node " << from
-                                  << " believes it is primary, but its election id "
-                                  << reply.electionId
-                                  << " is older than the most recent election id "
-                                  << _set->maxElectionId};
+            return false;
         }
 
         _set->maxElectionId = reply.electionId;
@@ -757,7 +744,7 @@ Status Refresher::receivedIsMasterFromMaster(const HostAndPort& from, const IsMa
     _scan->foundUpMaster = true;
     _set->lastSeenMaster = reply.host;
 
-    return Status::OK();
+    return true;
 }
 
 void Refresher::receivedIsMasterBeforeFoundMaster(const IsMasterReply& reply) {
@@ -802,23 +789,19 @@ HostAndPort Refresher::_refreshUntilMatches(const ReadPreferenceSetting* criteri
                 continue;
 
             case NextStep::CONTACT_HOST: {
-                StatusWith<BSONObj> isMasterReplyStatus{ErrorCodes::InternalError,
-                                                        "Uninitialized variable"};
+                BSONObj reply;  // empty on error
                 int64_t pingMicros = 0;
 
-                // Do not do network calls while holding a mutex
-                lk.unlock();
+                lk.unlock();  // relocked after attempting to call isMaster
                 try {
                     ScopedDbConnection conn(ConnectionString(ns.host), socketTimeoutSecs);
                     bool ignoredOutParam = false;
                     Timer timer;
-                    BSONObj reply;
                     conn->isMaster(ignoredOutParam, &reply);
-                    isMasterReplyStatus = reply;
                     pingMicros = timer.micros();
                     conn.done();  // return to pool on success.
-                } catch (const DBException& ex) {
-                    isMasterReplyStatus = ex.toStatus();
+                } catch (...) {
+                    reply = BSONObj();  // should be a no-op but want to be sure
                 }
                 lk.lock();
 
@@ -827,10 +810,10 @@ HostAndPort Refresher::_refreshUntilMatches(const ReadPreferenceSetting* criteri
                 if (_scan != _set->currentScan)
                     return criteria ? _set->getMatchingHost(*criteria) : HostAndPort();
 
-                if (isMasterReplyStatus.isOK())
-                    receivedIsMaster(ns.host, pingMicros, isMasterReplyStatus.getValue());
+                if (reply.isEmpty())
+                    failedHost(ns.host);
                 else
-                    failedHost(ns.host, isMasterReplyStatus.getStatus());
+                    receivedIsMaster(ns.host, pingMicros, reply);
             }
         }
     }
@@ -889,13 +872,10 @@ void IsMasterReply::parse(const BSONObj& obj) {
 
 Node::Node(const HostAndPort& host) : host(host), latencyMicros(unknownLatency) {}
 
-void Node::markFailed(const Status& status) {
-    if (isUp) {
-        log() << "Marking host " << host << " as failed" << causedBy(redact(status));
-
-        isUp = false;
-    }
+void Node::markFailed() {
+    LOG(1) << "Marking host " << host << " as failed";
 
+    isUp = false;
     isMaster = false;
 }
 
diff --git a/src/mongo/client/replica_set_monitor.h b/src/mongo/client/replica_set_monitor.h
index e83f41e4556..1b2db2c906f 100644
--- a/src/mongo/client/replica_set_monitor.h
+++ b/src/mongo/client/replica_set_monitor.h
@@ -106,14 +106,12 @@ public:
     Refresher startOrContinueRefresh();
 
     /**
-     * Notifies this Monitor that a host has failed because of the specified error 'status' and
-     * should be considered down.
+     * Notifies this Monitor that a host has failed and should be considered down.
      *
-     * Call this when you get a connection error. If you get an error while trying to refresh our
-     * view of a host, call Refresher::failedHost instead because it bypasses taking the monitor's
-     * mutex.
+     * Call this when you get a connection error. If you get an error while trying to refresh
+     * our view of a host, call Refresher::hostFailed() instead.
      */
-    void failedHost(const HostAndPort& host, const Status& status);
+    void failedHost(const HostAndPort& host);
 
     /**
      * Returns true if this node is the master based ONLY on local data. Be careful, return may
@@ -341,7 +339,7 @@ public:
     /**
      * Call this if a host returned from getNextStep failed to reply to an isMaster call.
      */
-    void failedHost(const HostAndPort& host, const Status& status);
+    void failedHost(const HostAndPort& host);
 
     /**
      * True if this Refresher started a new full scan rather than joining an existing one.
@@ -357,17 +355,15 @@ public:
 
 private:
     /**
-     * First, checks that the "reply" is not from a stale primary by comparing the electionId of
-     * "reply" to the maxElectionId recorded by the SetState and returns OK status if "reply"
-     * belongs to a non-stale primary. Otherwise returns a failed status.
-     *
-     * The 'from' parameter specifies the node from which the response is received.
+     * First, checks that the "reply" is not from a stale primary by
+     * comparing the electionId of "reply" to the maxElectionId recorded by the SetState.
+     * Returns true if "reply" belongs to a non-stale primary.
      *
      * Updates _set and _scan based on set-membership information from a master.
      * Applies _scan->unconfirmedReplies to confirmed nodes.
      * Does not update this host's node in _set->nodes.
      */
-    Status receivedIsMasterFromMaster(const HostAndPort& from, const IsMasterReply& reply);
+    bool receivedIsMasterFromMaster(const IsMasterReply& reply);
 
     /**
      * Adjusts the _scan work queue based on information from this host.
diff --git a/src/mongo/client/replica_set_monitor_internal.h b/src/mongo/client/replica_set_monitor_internal.h
index 237401b1f41..300452398b7 100644
--- a/src/mongo/client/replica_set_monitor_internal.h
+++ b/src/mongo/client/replica_set_monitor_internal.h
@@ -93,7 +93,7 @@ public:
     struct Node {
         explicit Node(const HostAndPort& host);
 
-        void markFailed(const Status& status);
+        void markFailed();
 
         bool matches(const ReadPreference pref) const;
 
diff --git a/src/mongo/client/replica_set_monitor_read_preference_test.cpp b/src/mongo/client/replica_set_monitor_read_preference_test.cpp
index 0344a08ff9f..956f40003bc 100644
--- a/src/mongo/client/replica_set_monitor_read_preference_test.cpp
+++ b/src/mongo/client/replica_set_monitor_read_preference_test.cpp
@@ -36,9 +36,9 @@
 #include "mongo/stdx/memory.h"
 #include "mongo/unittest/unittest.h"
 
-namespace mongo {
 namespace {
 
+using namespace mongo;
 using std::set;
 using std::vector;
 
@@ -145,7 +145,7 @@ TEST(ReplSetMonitorReadPref, PrimaryOnlyPriNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -183,7 +183,7 @@ TEST(ReplSetMonitorReadPref, PriPrefWithPriNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -197,7 +197,7 @@ TEST(ReplSetMonitorReadPref, SecOnly) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -211,8 +211,8 @@ TEST(ReplSetMonitorReadPref, SecOnlyOnlyPriOk) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -225,7 +225,7 @@ TEST(ReplSetMonitorReadPref, SecPref) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -239,8 +239,8 @@ TEST(ReplSetMonitorReadPref, SecPrefWithNoSecOk) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -254,9 +254,9 @@ TEST(ReplSetMonitorReadPref, SecPrefWithNoNodeOk) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getDefaultTagSet());
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
+    nodes[1].markFailed();
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -315,7 +315,7 @@ TEST(ReplSetMonitorReadPref, PriPrefPriNotOkWithTags) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getP2TagSet());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -341,7 +341,7 @@ TEST(ReplSetMonitorReadPref, PriPrefPriNotOkWithTagsNoMatch) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getSingleNoMatchTag());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -397,7 +397,7 @@ TEST(ReplSetMonitorReadPref, SecPrefSecNotOkWithTags) {
                              << "nyc"));
     TagSet tags(arrayBuilder.arr());
 
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -423,7 +423,7 @@ TEST(ReplSetMonitorReadPref, SecPrefPriNotOkWithTagsNoMatch) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getSingleNoMatchTag());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -487,7 +487,7 @@ TEST(ReplSetMonitorReadPref, MultiPriOnlyPriNotOkTag) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getMultiNoMatchTag());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -595,7 +595,7 @@ private:
 TEST_F(MultiTags, MultiTagsMatchesFirst) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -611,8 +611,8 @@ TEST_F(MultiTags, MultiTagsMatchesFirst) {
 TEST_F(MultiTags, PriPrefPriNotOkMatchesFirstNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -628,7 +628,7 @@ TEST_F(MultiTags, PriPrefPriNotOkMatchesFirstNotOk) {
 TEST_F(MultiTags, PriPrefPriNotOkMatchesSecondTest) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -644,8 +644,8 @@ TEST_F(MultiTags, PriPrefPriNotOkMatchesSecondTest) {
 TEST_F(MultiTags, PriPrefPriNotOkMatchesSecondNotOkTest) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -661,7 +661,7 @@ TEST_F(MultiTags, PriPrefPriNotOkMatchesSecondNotOkTest) {
 TEST_F(MultiTags, PriPrefPriNotOkMatchesLastTest) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -677,8 +677,8 @@ TEST_F(MultiTags, PriPrefPriNotOkMatchesLastTest) {
 TEST_F(MultiTags, PriPrefPriNotOkMatchesLastNotOkTest) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -707,7 +707,7 @@ TEST(MultiTags, PriPrefPriNotOkNoMatch) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getMultiNoMatchTag());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -733,7 +733,7 @@ TEST_F(MultiTags, SecOnlyMatchesFirstTest) {
 TEST_F(MultiTags, SecOnlyMatchesFirstNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -763,7 +763,7 @@ TEST_F(MultiTags, SecOnlyMatchesSecond) {
 TEST_F(MultiTags, SecOnlyMatchesSecondNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -790,7 +790,7 @@ TEST_F(MultiTags, SecOnlyMatchesLast) {
 TEST_F(MultiTags, SecOnlyMatchesLastNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(
@@ -838,7 +838,7 @@ TEST_F(MultiTags, SecPrefMatchesFirst) {
 TEST_F(MultiTags, SecPrefMatchesFirstNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -868,7 +868,7 @@ TEST_F(MultiTags, SecPrefMatchesSecond) {
 TEST_F(MultiTags, SecPrefMatchesSecondNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -898,7 +898,7 @@ TEST_F(MultiTags, SecPrefMatchesLast) {
 TEST_F(MultiTags, SecPrefMatchesLastNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(nodes,
@@ -941,7 +941,7 @@ TEST(MultiTags, SecPrefMultiTagsNoMatchPriNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
     TagSet tags(getMultiNoMatchTag());
 
-    nodes[1].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[1].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -972,7 +972,7 @@ TEST(MultiTags, NearestMatchesFirstNotOk) {
 
     TagSet tags(arrayBuilder.arr());
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -1006,7 +1006,7 @@ TEST_F(MultiTags, NearestMatchesSecondNotOk) {
 
     TagSet tags(arrayBuilder.arr());
 
-    nodes[2].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[2].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host =
@@ -1030,7 +1030,7 @@ TEST_F(MultiTags, NearestMatchesLast) {
 TEST_F(MultiTags, NeatestMatchesLastNotOk) {
     vector<Node> nodes = getThreeMemberWithTags();
 
-    nodes[0].markFailed({ErrorCodes::InternalError, "Test error"});
+    nodes[0].markFailed();
 
     bool isPrimarySelected = false;
     HostAndPort host = selectNode(
@@ -1065,6 +1065,4 @@ TEST(TagSet, DefaultConstructorMatchesAll) {
     TagSet tags;
     ASSERT_BSONOBJ_EQ(tags.getTagBSON(), BSON_ARRAY(BSONObj()));
 }
-
-}  // namespace
-}  // namespace mongo
+}
diff --git a/src/mongo/client/replica_set_monitor_test.cpp b/src/mongo/client/replica_set_monitor_test.cpp
index 8720176b183..45cd93cc7e2 100644
--- a/src/mongo/client/replica_set_monitor_test.cpp
+++ b/src/mongo/client/replica_set_monitor_test.cpp
@@ -28,13 +28,15 @@
 
 #include "mongo/platform/basic.h"
 
+
 #include "mongo/client/replica_set_monitor.h"
 #include "mongo/client/replica_set_monitor_internal.h"
 #include "mongo/unittest/unittest.h"
 
-namespace mongo {
+
 namespace {
 
+using namespace mongo;
 using std::set;
 
 // Pull nested types to top-level scope
@@ -940,7 +942,7 @@ TEST(ReplicaSetMonitor, OutOfBandFailedHost) {
 
         if (i >= 1) {
             HostAndPort a("a");
-            rsm->failedHost(a, {ErrorCodes::InternalError, "Test error"});
+            rsm->failedHost(a);
             Node* node = state->findNode(a);
             ASSERT(node);
             ASSERT(!node->isUp);
@@ -1510,9 +1512,9 @@ TEST(ReplicaSetMonitor, MaxStalenessMSAllFailed) {
     ASSERT_EQUALS(ns.step, NextStep::DONE);
 
     // make sure all secondaries are in the scan
-    refresher.failedHost(HostAndPort("a"), {ErrorCodes::InternalError, "Test error"});
-    refresher.failedHost(HostAndPort("b"), {ErrorCodes::InternalError, "Test error"});
-    refresher.failedHost(HostAndPort("c"), {ErrorCodes::InternalError, "Test error"});
+    refresher.failedHost(HostAndPort("a"));
+    refresher.failedHost(HostAndPort("b"));
+    refresher.failedHost(HostAndPort("c"));
 
     HostAndPort notStale = state->getMatchingHost(secondary);
     ASSERT_EQUALS(notStale.host(), "");
@@ -1562,8 +1564,8 @@ TEST(ReplicaSetMonitor, MaxStalenessMSAllButPrimaryFailed) {
 
     // make sure the primary is in the scan
     ASSERT(state->findNode(HostAndPort("a")));
-    refresher.failedHost(HostAndPort("b"), {ErrorCodes::InternalError, "Test error"});
-    refresher.failedHost(HostAndPort("c"), {ErrorCodes::InternalError, "Test error"});
+    refresher.failedHost(HostAndPort("b"));
+    refresher.failedHost(HostAndPort("c"));
 
     // No match because the request needs secondaryOnly host
     HostAndPort notStale = state->getMatchingHost(secondary);
@@ -1614,7 +1616,7 @@ TEST(ReplicaSetMonitor, MaxStalenessMSOneSecondaryFailed) {
 
     ASSERT(state->findNode(HostAndPort("a")));
     ASSERT(state->findNode(HostAndPort("b")));
-    refresher.failedHost(HostAndPort("c"), {ErrorCodes::InternalError, "Test error"});
+    refresher.failedHost(HostAndPort("c"));
 
     // No match because the write date is stale
     HostAndPort notStale = state->getMatchingHost(secondary);
@@ -1665,9 +1667,9 @@ TEST(ReplicaSetMonitor, MaxStalenessMSNonStaleSecondaryMatched) {
     // Ensure that we have heard from all hosts and scan is done
     ASSERT_EQUALS(ns.step, NextStep::DONE);
 
-    refresher.failedHost(HostAndPort("a"), {ErrorCodes::InternalError, "Test error"});
+    refresher.failedHost(HostAndPort("a"));
     ASSERT(state->findNode(HostAndPort("b")));
-    refresher.failedHost(HostAndPort("c"), {ErrorCodes::InternalError, "Test error"});
+    refresher.failedHost(HostAndPort("c"));
 
     HostAndPort notStale = state->getMatchingHost(secondary);
     ASSERT_EQUALS(notStale.host(), "b");
@@ -1895,5 +1897,5 @@ TEST(ReplicaSetMonitor, MinOpTimeIgnored) {
     ASSERT_EQUALS(notStale.host(), "c");
 }
 
+
 }  // namespace
-}  // namespace mongo
diff --git a/src/mongo/dbtests/replica_set_monitor_test.cpp b/src/mongo/dbtests/replica_set_monitor_test.cpp
index 69cbe39e1d6..d6454fc50c2 100644
--- a/src/mongo/dbtests/replica_set_monitor_test.cpp
+++ b/src/mongo/dbtests/replica_set_monitor_test.cpp
@@ -28,9 +28,6 @@
 
 #include "mongo/platform/basic.h"
 
-#include <set>
-#include <vector>
-
 #include "mongo/client/connpool.h"
 #include "mongo/client/dbclient_rs.h"
 #include "mongo/client/dbclientinterface.h"
@@ -40,9 +37,13 @@
 #include "mongo/dbtests/mock/mock_replica_set.h"
 #include "mongo/unittest/unittest.h"
 
-namespace mongo {
+#include <set>
+#include <vector>
+
 namespace {
 
+using namespace mongo;
+
 using std::map;
 using std::vector;
 using std::set;
@@ -302,5 +303,4 @@ TEST_F(TwoNodeWithTags, SecDownRetryWithTag) {
     monitor.reset();
 }
 
-}  // namespace
 }  // namespace mongo
diff --git a/src/mongo/s/client/shard_remote.cpp b/src/mongo/s/client/shard_remote.cpp
index 64d4f58ff1f..997c32c2387 100644
--- a/src/mongo/s/client/shard_remote.cpp
+++ b/src/mongo/s/client/shard_remote.cpp
@@ -126,13 +126,13 @@ void ShardRemote::updateReplSetMonitor(const HostAndPort& remoteHost,
     if (ErrorCodes::isNotMasterError(remoteCommandStatus.code()) ||
         (remoteCommandStatus == ErrorCodes::InterruptedDueToReplStateChange) ||
         (remoteCommandStatus == ErrorCodes::PrimarySteppedDown)) {
-        _targeter->markHostNotMaster(remoteHost, remoteCommandStatus);
+        _targeter->markHostNotMaster(remoteHost);
     } else if (ErrorCodes::isNetworkError(remoteCommandStatus.code())) {
-        _targeter->markHostUnreachable(remoteHost, remoteCommandStatus);
+        _targeter->markHostUnreachable(remoteHost);
     } else if (remoteCommandStatus == ErrorCodes::NotMasterOrSecondary) {
-        _targeter->markHostUnreachable(remoteHost, remoteCommandStatus);
+        _targeter->markHostUnreachable(remoteHost);
     } else if (remoteCommandStatus == ErrorCodes::ExceededTimeLimit) {
-        _targeter->markHostUnreachable(remoteHost, remoteCommandStatus);
+        _targeter->markHostUnreachable(remoteHost);
     }
 }
 
diff --git a/src/mongo/util/net/hostandport.cpp b/src/mongo/util/net/hostandport.cpp
index abd8f2d6ade..04088d21861 100644
--- a/src/mongo/util/net/hostandport.cpp
+++ b/src/mongo/util/net/hostandport.cpp
@@ -180,16 +180,6 @@ std::ostream& operator<<(std::ostream& os, const HostAndPort& hp) {
     return os << hp.toString();
 }
 
-template <typename Allocator>
-StringBuilderImpl<Allocator>& operator<<(StringBuilderImpl<Allocator>& os, const HostAndPort& hp) {
-    return os << hp.toString();
-}
-
-template StringBuilderImpl<StackAllocator>& operator<<(StringBuilderImpl<StackAllocator>&,
-                                                       const HostAndPort&);
-template StringBuilderImpl<SharedBufferAllocator>& operator<<(
-    StringBuilderImpl<SharedBufferAllocator>&, const HostAndPort&);
-
 }  // namespace mongo
 
 MONGO_HASH_NAMESPACE_START
diff --git a/src/mongo/util/net/hostandport.h b/src/mongo/util/net/hostandport.h
index 53209bbaa04..6f7bd46b43c 100644
--- a/src/mongo/util/net/hostandport.h
+++ b/src/mongo/util/net/hostandport.h
@@ -34,10 +34,7 @@
 #include "mongo/platform/hash_namespace.h"
 
 namespace mongo {
-
 class Status;
-template <typename Allocator>
-class StringBuilderImpl;
 class StringData;
 template <typename T>
 class StatusWith;
@@ -127,9 +124,6 @@ private:
 
 std::ostream& operator<<(std::ostream& os, const HostAndPort& hp);
 
-template <typename Allocator>
-StringBuilderImpl<Allocator>& operator<<(StringBuilderImpl<Allocator>& os, const HostAndPort& hp);
-
 }  // namespace mongo
 
 MONGO_HASH_NAMESPACE_START