SERVER-27721 Implement rate limiter check for advancing logical clocks

1 files changed, 30 insertions, 0 deletions

diff --git a/src/mongo/db/logical_clock_test.cpp b/src/mongo/db/logical_clock_test.cpp
index bb8bdba9afc..a0b8dbaf30e 100644
--- a/src/mongo/db/logical_clock_test.cpp
+++ b/src/mongo/db/logical_clock_test.cpp
@@ -66,6 +66,11 @@ protected:
         return SignedLogicalTime(logicalTime, _timeProofService->getProof(logicalTime));
     }
 
+    const unsigned currentWallClockSecs() {
+        return durationCount<Seconds>(
+            _serviceContext->getFastClockSource()->now().toDurationSinceEpoch());
+    }
+
 private:
     TimeProofService* _timeProofService;
     std::unique_ptr<ServiceContextNoop> _serviceContext;
@@ -118,5 +123,30 @@ TEST_F(LogicalClockTestBase, advanceClusterTime) {
     ASSERT_TRUE(l1.getTime() == l2.getTime());
 }
 
+// Verify rate limiter rejects logical times whose seconds values are too far ahead.
+TEST_F(LogicalClockTestBase, RateLimiterRejectsLogicalTimesTooFarAhead) {
+    Timestamp tooFarAheadTimestamp(
+        currentWallClockSecs() +
+            durationCount<Seconds>(LogicalClock::kMaxAcceptableLogicalClockDrift) +
+            10,  // Add 10 seconds to ensure limit is exceeded.
+        1);
+    SignedLogicalTime l1 = makeSignedLogicalTime(LogicalTime(tooFarAheadTimestamp));
+
+    ASSERT_EQ(ErrorCodes::ClusterTimeFailsRateLimiter, getClock()->advanceClusterTime(l1));
+    ASSERT_EQ(ErrorCodes::ClusterTimeFailsRateLimiter,
+              getClock()->advanceClusterTimeFromTrustedSource(l1));
+}
+
+// Verify cluster time can be initialized to a very old time.
+TEST_F(LogicalClockTestBase, InitFromTrustedSourceCanAcceptVeryOldLogicalTime) {
+    Timestamp veryOldTimestamp(
+        currentWallClockSecs() -
+        (durationCount<Seconds>(LogicalClock::kMaxAcceptableLogicalClockDrift) * 5));
+    auto veryOldTime = LogicalTime(veryOldTimestamp);
+    getClock()->initClusterTimeFromTrustedSource(veryOldTime);
+
+    ASSERT_TRUE(getClock()->getClusterTime().getTime() == veryOldTime);
+}
+
 }  // unnamed namespace
 }  // namespace mongo