1 files changed, 7 insertions, 24 deletions

diff --git a/src/mongo/client/sdam/server_description.cpp b/src/mongo/client/sdam/server_description.cpp
index 79b9cafdecf..62092a0de6c 100644
--- a/src/mongo/client/sdam/server_description.cpp
+++ b/src/mongo/client/sdam/server_description.cpp
@@ -62,7 +62,7 @@ ServerDescription::ServerDescription(ClockSource* clockSource,
 
         // type must be parsed before RTT is calculated.
         parseTypeFromIsMaster(response);
-        calculateRtt(isMasterOutcome.getRtt(), lastRtt);
+        calculateRtt(*isMasterOutcome.getRtt(), lastRtt);
 
         _lastUpdateTime = clockSource->now();
         _minWireVersion = response["minWireVersion"].numberInt();
@@ -160,7 +160,7 @@ void ServerDescription::saveStreamable(BSONElement streamableField) {
     _streamable = streamableField && streamableField.Bool();
 }
 
-void ServerDescription::calculateRtt(const boost::optional<IsMasterRTT> currentRtt,
+void ServerDescription::calculateRtt(const IsMasterRTT currentRtt,
                                      const boost::optional<IsMasterRTT> lastRtt) {
     if (getType() == ServerType::kUnknown) {
         // if a server's type is Unknown, it's RTT is null
@@ -169,28 +169,12 @@ void ServerDescription::calculateRtt(const boost::optional<IsMasterRTT> currentR
         return;
     }
 
-    if (currentRtt == boost::none) {
-        // An onServerHeartbeatSucceededEvent occured. Note: This should not be reached by an
-        // onServerHeartbeatFailedEvent. Upon the failed event, the type is set to
-        // ServerType::Unknown.
-
-        // The ServerType is no longer ServerType::Unknown, but the ServerPingMonitor has not
-        // updated the RTT yet. Set the _rtt to max() until the ServerPingMonitor provides the
-        // accurate RTT measurement.
-        if (lastRtt == boost::none) {
-            _rtt = IsMasterRTT::max();
-            return;
-        }
-
-        // Do not update the RTT upon an onServerHeartbeatSucceededEvent.
-        _rtt = lastRtt;
-    } else if (lastRtt == boost::none || lastRtt == IsMasterRTT::max()) {
-        // The lastRtt either does not exist or is not accurate. Discard it and use the currentRtt.
-        _rtt = currentRtt;
-    } else {
+    if (lastRtt) {
         // new_rtt = alpha * x + (1 - alpha) * old_rtt
-        _rtt = IsMasterRTT(static_cast<IsMasterRTT::rep>(kRttAlpha * currentRtt.get().count() +
+        _rtt = IsMasterRTT(static_cast<IsMasterRTT::rep>(kRttAlpha * currentRtt.count() +
                                                          (1 - kRttAlpha) * lastRtt.get().count()));
+    } else {
+        _rtt = currentRtt;
     }
 }
 
@@ -445,8 +429,7 @@ std::string ServerDescription::toString() const {
 
 ServerDescriptionPtr ServerDescription::cloneWithRTT(IsMasterRTT rtt) {
     auto newServerDescription = std::make_shared<ServerDescription>(*this);
-    auto lastRtt = newServerDescription->getRtt();
-    newServerDescription->calculateRtt(rtt, lastRtt);
+    newServerDescription->_rtt = rtt;
     return newServerDescription;
 }