SERVER-56489: New pass-through test with hello server-side delays

3 files changed, 27 insertions, 13 deletions

diff --git a/src/mongo/client/scanning_replica_set_monitor.cpp b/src/mongo/client/scanning_replica_set_monitor.cpp
index afe643a8d14..0902abd94e0 100644
--- a/src/mongo/client/scanning_replica_set_monitor.cpp
+++ b/src/mongo/client/scanning_replica_set_monitor.cpp
@@ -246,7 +246,7 @@ void ScanningReplicaSetMonitor::SetState::rescheduleRefresh(SchedulingStrategy s
         return;
     }
 
-    Milliseconds period = refreshPeriod;
+    Milliseconds period = _getRefreshPeriod();  // Supports fail injection.
     if (isExpedited) {
         period = std::min<Milliseconds>(period, kExpeditedRefreshPeriod);
     }
@@ -495,14 +495,20 @@ bool ScanningReplicaSetMonitor::isKnownToHaveGoodPrimary() const {
     return false;
 }
 
-Seconds ScanningReplicaSetMonitor::getDefaultRefreshPeriod() {
-    Seconds r = kDefaultRefreshPeriod;
+Seconds ScanningReplicaSetMonitor::_getRefreshPeriod() {
+    boost::optional<Seconds> failInjected = _getFailInjectedRefreshPeriod();
+    return failInjected ? *failInjected : kDefaultRefreshPeriod;
+}
+
+boost::optional<Seconds> ScanningReplicaSetMonitor::_getFailInjectedRefreshPeriod() {
+    boost::optional<Seconds> result;
     static constexpr auto kPeriodField = "period"_sd;
     globalFailPointRegistry()
         .find("modifyReplicaSetMonitorDefaultRefreshPeriod")
-        ->executeIf([&r](const BSONObj& data) { r = Seconds{data.getIntField(kPeriodField)}; },
-                    [](const BSONObj& data) { return data.hasField(kPeriodField); });
-    return r;
+        ->executeIf(
+            [&result](const BSONObj& data) { result = Seconds{data.getIntField(kPeriodField)}; },
+            [](const BSONObj& data) { return data.hasField(kPeriodField); });
+    return result;
 }
 
 void ScanningReplicaSetMonitor::runScanForMockReplicaSet() {
@@ -1138,7 +1144,7 @@ SetState::SetState(const MongoURI& uri,
       seedNodes(setUri.getServers().begin(), setUri.getServers().end()),
       latencyThresholdMicros(serverGlobalParams.defaultLocalThresholdMillis * int64_t(1000)),
       rand(std::random_device()()),
-      refreshPeriod(getDefaultRefreshPeriod()) {
+      refreshPeriod(_getRefreshPeriod()) {
     uassert(13642, "Replica set seed list can't be empty", !seedNodes.empty());
 
     if (name.empty())
diff --git a/src/mongo/client/scanning_replica_set_monitor.h b/src/mongo/client/scanning_replica_set_monitor.h
index 094db3e3300..85295e099f1 100644
--- a/src/mongo/client/scanning_replica_set_monitor.h
+++ b/src/mongo/client/scanning_replica_set_monitor.h
@@ -123,11 +123,6 @@ public:
 
     bool isKnownToHaveGoodPrimary() const override;
 
-    /**
-     * Returns the refresh period that is given to all new SetStates.
-     */
-    static Seconds getDefaultRefreshPeriod();
-
     //
     // internal types (defined in scanning_replica_set_monitor_internal.h)
     //
@@ -160,12 +155,23 @@ private:
         const ReadPreferenceSetting& readPref,
         Milliseconds maxWait,
         const std::vector<HostAndPort>& excludedHosts);
+
     /**
      * If no scan is in-progress, this function is responsible for setting up a new scan. Otherwise,
      * does nothing.
      */
     static void _ensureScanInProgress(const SetStatePtr&);
 
+    /**
+     * Returns the refresh period that is given to all new SetStates.
+     */
+    static Seconds _getRefreshPeriod();
+
+    /**
+     * Returns fail injected refresh period, if fail point is set.
+     */
+    static boost::optional<Seconds> _getFailInjectedRefreshPeriod();
+
     const SetStatePtr _state;
 };
 
diff --git a/src/mongo/client/server_discovery_monitor.cpp b/src/mongo/client/server_discovery_monitor.cpp
index e7bfe11c8e0..6785aed62bb 100644
--- a/src/mongo/client/server_discovery_monitor.cpp
+++ b/src/mongo/client/server_discovery_monitor.cpp
@@ -437,7 +437,9 @@ Milliseconds SingleServerDiscoveryMonitor::_currentRefreshPeriod(WithLock,
     if (scheduleImmediately)
         return Milliseconds(0);
 
-    return (_isExpedited) ? sdam::SdamConfiguration::kMinHeartbeatFrequency : _heartbeatFrequency;
+    // The _overrideRefreshPeriod() supports fail injection.
+    return (_isExpedited) ? sdam::SdamConfiguration::kMinHeartbeatFrequency
+                          : _overrideRefreshPeriod(_heartbeatFrequency);
 }
 
 void SingleServerDiscoveryMonitor::disableExpeditedChecking() {