SERVER-70264 make slowMS and sampleRate atomic

2 files changed, 5 insertions, 4 deletions

diff --git a/src/mongo/util/log_with_sampling.h b/src/mongo/util/log_with_sampling.h
index eb95aec5040..e3407c26e07 100644
--- a/src/mongo/util/log_with_sampling.h
+++ b/src/mongo/util/log_with_sampling.h
@@ -50,7 +50,7 @@ inline std::pair<bool, bool> shouldLogSlowOpWithSampling(OperationContext* opCtx
 
     const auto client = opCtx->getClient();
     const bool shouldSample =
-        client->getPrng().nextCanonicalDouble() < serverGlobalParams.sampleRate;
+        client->getPrng().nextCanonicalDouble() < serverGlobalParams.sampleRate.load();
 
     // Log the transaction if we should sample and its duration is greater than or equal to the
     // slowMS command threshold.
diff --git a/src/mongo/util/log_with_sampling_test.cpp b/src/mongo/util/log_with_sampling_test.cpp
index 88b3aebe91e..4a184485f95 100644
--- a/src/mongo/util/log_with_sampling_test.cpp
+++ b/src/mongo/util/log_with_sampling_test.cpp
@@ -65,9 +65,10 @@ auto scenario(bool debugLogEnabled, bool slowOp, bool forceSample) {
     auto loggedSeverityGuard = unittest::MinimumLoggedSeverityGuard(
         component, debugLogEnabled ? logv2::LogSeverity::Debug(1) : logv2::LogSeverity::Info());
 
-    ScopeGuard sampleRateGuard(
-        [savedRate = serverGlobalParams.sampleRate] { serverGlobalParams.sampleRate = savedRate; });
-    serverGlobalParams.sampleRate = forceSample ? 1.0 : 0.0;
+    ScopeGuard sampleRateGuard([savedRate = serverGlobalParams.sampleRate.load()] {
+        serverGlobalParams.sampleRate.store(savedRate);
+    });
+    serverGlobalParams.sampleRate.store(forceSample ? 1.0 : 0.0);
 
     return shouldLogSlowOpWithSampling(
         opCtx.get(), component, Milliseconds{slowOp ? 11 : 9}, Milliseconds{10});