SERVER-58533 Log FCV at initialization and on log rotation

6 files changed, 27 insertions, 18 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 442bda2ad74..e2c119b9951 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -2007,6 +2007,7 @@ env.Library(
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/base',
+        '$BUILD_DIR/mongo/db/commands/mongod_fcv',
         '$BUILD_DIR/mongo/util/net/network',
         'repl/repl_coordinator_interface',
         'repl/replica_set_messages',
diff --git a/src/mongo/db/commands/feature_compatibility_version.cpp b/src/mongo/db/commands/feature_compatibility_version.cpp
index 7798cd2d2a6..78b2f6321af 100644
--- a/src/mongo/db/commands/feature_compatibility_version.cpp
+++ b/src/mongo/db/commands/feature_compatibility_version.cpp
@@ -421,7 +421,7 @@ void FeatureCompatibilityVersion::initializeForStartup(OperationContext* opCtx)
     invariant(opCtx->lockState()->isW());
     auto featureCompatibilityVersion = findFeatureCompatibilityVersionDocument(opCtx);
     if (!featureCompatibilityVersion) {
-        LOGV2(5853303, "featureCompatibilityVersion document missing at startup");
+        FeatureCompatibilityVersion::logFCVWithContext("startup"_sd);
         return;
     }
 
@@ -448,10 +448,7 @@ void FeatureCompatibilityVersion::initializeForStartup(OperationContext* opCtx)
     serverGlobalParams.mutableFeatureCompatibility.setVersion(version);
     FeatureCompatibilityVersion::updateMinWireVersion();
 
-    LOGV2(5853300,
-          "Intializing featureCompatibilityVersion at startup",
-          "featureCompatibilityVersion"_attr =
-              multiversion::toString(serverGlobalParams.featureCompatibility.getVersion()));
+    FeatureCompatibilityVersion::logFCVWithContext("startup"_sd);
 
     // On startup, if the version is in an upgrading or downgrading state, print a warning.
     if (serverGlobalParams.featureCompatibility.isUpgradingOrDowngrading()) {
@@ -520,6 +517,19 @@ void FeatureCompatibilityVersion::clearLastFCVUpdateTimestamp() {
     lastFCVUpdateTimestamp = Timestamp();
 }
 
+void FeatureCompatibilityVersion::logFCVWithContext(StringData context) {
+    LOGV2_OPTIONS(
+        5853300,
+        {logv2::LogComponent::kReplication},
+        "current featureCompatibilityVersion value",
+        "featureCompatibilityVersion"_attr =
+            serverGlobalParams.featureCompatibility.isVersionInitialized()
+            ? multiversion::toString(serverGlobalParams.featureCompatibility.getVersion())
+            : multiversion::toString(
+                  multiversion::FeatureCompatibilityVersion::kUnsetDefaultLastLTSBehavior),
+        "context"_attr = context);
+}
+
 
 /**
  * Read-only server parameter for featureCompatibilityVersion.
diff --git a/src/mongo/db/commands/feature_compatibility_version.h b/src/mongo/db/commands/feature_compatibility_version.h
index b6c5c537000..40764856f3a 100644
--- a/src/mongo/db/commands/feature_compatibility_version.h
+++ b/src/mongo/db/commands/feature_compatibility_version.h
@@ -124,6 +124,13 @@ public:
      * Also used in rare cases when the replication coordinator majority snapshot is cleared.
      */
     static void clearLastFCVUpdateTimestamp();
+
+    /**
+     * Logs the current FCV global state.
+     * context: the context in which this function was called, to differentiate logs (e.g.
+     * startup, log rotation).
+     */
+    static void logFCVWithContext(StringData context);
 };
 
 /**
diff --git a/src/mongo/db/fcv_op_observer.cpp b/src/mongo/db/fcv_op_observer.cpp
index 3a1ebd4195d..a08d45f37c6 100644
--- a/src/mongo/db/fcv_op_observer.cpp
+++ b/src/mongo/db/fcv_op_observer.cpp
@@ -65,6 +65,7 @@ void FcvOpObserver::_setVersion(OperationContext* opCtx,
         prevVersion = serverGlobalParams.featureCompatibility.getVersion();
     }
     serverGlobalParams.mutableFeatureCompatibility.setVersion(newVersion);
+    FeatureCompatibilityVersion::logFCVWithContext("setFCV"_sd);
     FeatureCompatibilityVersion::updateMinWireVersion();
 
     // (Generic FCV reference): This FCV check should exist across LTS binary versions.
diff --git a/src/mongo/db/log_process_details.cpp b/src/mongo/db/log_process_details.cpp
index 16e70222266..687037ae4cc 100644
--- a/src/mongo/db/log_process_details.cpp
+++ b/src/mongo/db/log_process_details.cpp
@@ -38,6 +38,7 @@
 #include "mongo/bson/bsonobj.h"
 #include "mongo/bson/bsonobjbuilder.h"
 #include "mongo/bson/json.h"
+#include "mongo/db/commands/feature_compatibility_version.h"
 #include "mongo/db/repl/repl_set_config.h"
 #include "mongo/db/repl/replication_coordinator.h"
 #include "mongo/db/server_options.h"
@@ -103,14 +104,7 @@ void logProcessDetailsForLogRotate(ServiceContext* serviceContext) {
         }
     }
 
-    LOGV2(5853301,
-          "featureCompatibilityVersion on log rotation",
-          "featureCompatibilityVersion"_attr =
-              serverGlobalParams.featureCompatibility.isVersionInitialized()
-              ? multiversion::toString(serverGlobalParams.featureCompatibility.getVersion())
-              : multiversion::toString(
-                    multiversion::FeatureCompatibilityVersion::kUnsetDefaultLastLTSBehavior));
-
+    FeatureCompatibilityVersion::logFCVWithContext("log rotation"_sd);
     logProcessDetails(nullptr);
 }
 
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 4a7c66832d1..3384197b1a9 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -4417,11 +4417,7 @@ ReplicationCoordinatorImpl::_updateMemberStateFromTopologyCoordinator(WithLock l
         // (Generic FCV reference): This FCV check should exist across LTS binary versions.
         serverGlobalParams.mutableFeatureCompatibility.setVersion(
             multiversion::GenericFCV::kLatest);
-        LOGV2(5853302,
-              "Update featureCompatibilityVersion because arbiters do not receive the replicated "
-              "version",
-              "featureCompatibilityVersion"_attr =
-                  multiversion::toString(serverGlobalParams.featureCompatibility.getVersion()));
+        FeatureCompatibilityVersion::logFCVWithContext("arbiter"_sd);
     }
 
     _memberState = newState;