SERVER-52654 HMAC keys monitoring thread should never sleep longer than 20 days

2 files changed, 59 insertions, 19 deletions

diff --git a/src/mongo/db/keys_collection_manager.cpp b/src/mongo/db/keys_collection_manager.cpp
index 86a95a1a864..45d81b2aa96 100644
--- a/src/mongo/db/keys_collection_manager.cpp
+++ b/src/mongo/db/keys_collection_manager.cpp
@@ -55,7 +55,11 @@ namespace {
 
 Milliseconds kDefaultRefreshWaitTime(30 * 1000);
 Milliseconds kRefreshIntervalIfErrored(200);
-Milliseconds kMaxRefreshWaitTime(10 * 60 * 1000);
+Milliseconds kMaxRefreshWaitTimeIfErrored(10 * 60 * 1000);
+// Never wait more than the number of milliseconds in 20 days to avoid sleeping for a number greater
+// than can fit in a signed 32 bit integer.
+// 20 days = 1000 * 60 * 60 * 24 * 20 = 1,728,000,000 vs signed integer max of 2,147,483,648.
+Milliseconds kMaxRefreshWaitTimeOnSuccess(Days(20));
 
 // Prevents the refresher thread from waiting longer than the given number of milliseconds, even on
 // a successful refresh.
@@ -79,11 +83,7 @@ Milliseconds howMuchSleepNeedFor(const LogicalTime& currentTime,
 
     Milliseconds millisBeforeExpire = Milliseconds(expiredSecs) - Milliseconds(currentSecs);
 
-    if (interval <= millisBeforeExpire) {
-        return interval;
-    }
-
-    return millisBeforeExpire;
+    return std::min({millisBeforeExpire, interval, kMaxRefreshWaitTimeOnSuccess});
 }
 
 }  // namespace keys_collection_manager_util
@@ -261,8 +261,8 @@ void KeysCollectionManager::PeriodicRunner::_doPeriodicRefresh(ServiceContext* s
             } else {
                 errorCount += 1;
                 nextWakeup = Milliseconds(kRefreshIntervalIfErrored.count() * errorCount);
-                if (nextWakeup > kMaxRefreshWaitTime) {
-                    nextWakeup = kMaxRefreshWaitTime;
+                if (nextWakeup > kMaxRefreshWaitTimeIfErrored) {
+                    nextWakeup = kMaxRefreshWaitTimeIfErrored;
                 }
                 LOGV2(4939300,
                       "Failed to refresh key cache",
diff --git a/src/mongo/db/keys_collection_manager_sharding_test.cpp b/src/mongo/db/keys_collection_manager_sharding_test.cpp
index dc19e7f5c9e..ced4613ef26 100644
--- a/src/mongo/db/keys_collection_manager_sharding_test.cpp
+++ b/src/mongo/db/keys_collection_manager_sharding_test.cpp
@@ -376,27 +376,67 @@ LogicalTime addSeconds(const LogicalTime& logicalTime, const Seconds& seconds) {
     return LogicalTime(Timestamp(asTimestamp.getSecs() + seconds.count(), asTimestamp.getInc()));
 }
 
-TEST(KeysCollectionManagerUtilTest, HowMuchSleepNeededForCalculationDoesNotOverflow) {
+TEST(KeysCollectionManagerUtilTest, HowMuchSleepNeedForWithDefaultKeysRotationIntervalIs20Days) {
     auto secondsSinceEpoch = durationCount<Seconds>(Date_t::now().toDurationSinceEpoch());
     auto defaultKeysIntervalSeconds = Seconds(KeysRotationIntervalSec);
 
-    // Mock inputs that would have caused an overflow without the changes from SERVER-48709.
-    // "currentTime" is the current clusterTime in the VectorClock, which will typically be close
-    // to a timestamp constructed from the number of seconds since the unix epoch. "latestExpiredAt"
-    // is the highest expiration logical time of any key, which will at most be currentTime +
-    // (default key rotation interval * 2) because two valid keys are kept at a time. "interval" is
-    // the duration a key is valid for, which defaults to 90 days = 7,776,000 seconds.
     auto currentTime = LogicalTime(Timestamp(secondsSinceEpoch, 0));
     auto latestExpiredAt = addSeconds(currentTime, defaultKeysIntervalSeconds * 2);
-    auto interval = Milliseconds(defaultKeysIntervalSeconds);
+    auto defaultInterval = Milliseconds(defaultKeysIntervalSeconds);
+
+    auto nextWakeupMillis = keys_collection_manager_util::howMuchSleepNeedFor(
+        currentTime, latestExpiredAt, defaultInterval);
+    ASSERT_EQ(nextWakeupMillis, Days(20));
+}
+
+TEST(KeysCollectionManagerUtilTest, HowMuchSleepNeedForIsNeverLongerThan20Days) {
+    auto secondsSinceEpoch = durationCount<Seconds>(Date_t::now().toDurationSinceEpoch());
+    auto keysRotationInterval = Seconds(Days(50));
+
+    auto currentTime = LogicalTime(Timestamp(secondsSinceEpoch, 0));
+    auto latestExpiredAt = addSeconds(currentTime, keysRotationInterval * 2);
+    auto interval = Milliseconds(keysRotationInterval);
+
+    auto nextWakeupMillis =
+        keys_collection_manager_util::howMuchSleepNeedFor(currentTime, latestExpiredAt, interval);
+    ASSERT_EQ(nextWakeupMillis, Days(20));
+}
+
+TEST(KeysCollectionManagerUtilTest, HowMuchSleepNeedForIsNeverHigherThanRotationInterval) {
+    auto secondsSinceEpoch = durationCount<Seconds>(Date_t::now().toDurationSinceEpoch());
+    auto keysRotationInterval = Seconds(Days(5));
+
+    auto currentTime = LogicalTime(Timestamp(secondsSinceEpoch, 0));
+    auto latestExpiredAt = addSeconds(currentTime, keysRotationInterval * 2);
+    auto interval = Milliseconds(keysRotationInterval);
 
-    // Despite the default rotation interval seconds * 1000 not fitting in a 32 bit unsigned
-    // integer (7,776,000,000 vs. 4,294,967,295), the calculation should not overflow, and the next
-    // wakeup should correctly be the default interval.
     auto nextWakeupMillis =
         keys_collection_manager_util::howMuchSleepNeedFor(currentTime, latestExpiredAt, interval);
     ASSERT_EQ(nextWakeupMillis, interval);
 }
 
+LogicalTime subtractSeconds(const LogicalTime& logicalTime, const Seconds& seconds) {
+    auto asTimestamp = logicalTime.asTimestamp();
+    return LogicalTime(Timestamp(asTimestamp.getSecs() - seconds.count(), asTimestamp.getInc()));
+}
+
+TEST(KeysCollectionManagerUtilTest, HowMuchSleepNeedForAfterNotFindingKeys) {
+    // Default refresh interval if keys could not be found.
+    const Milliseconds kRefreshIntervalIfErrored(200);
+
+    auto secondsSinceEpoch = durationCount<Seconds>(Date_t::now().toDurationSinceEpoch());
+    auto keysRotationInterval = Milliseconds(5000);
+
+    // The latest found key expired before the current time, which means no new keys were found
+    // despite the previous refresh succeeding.
+    auto currentTime = LogicalTime(Timestamp(secondsSinceEpoch, 0));
+    auto latestExpiredAt = subtractSeconds(currentTime, Seconds(1));
+    auto interval = Milliseconds(keysRotationInterval);
+
+    auto nextWakeupMillis =
+        keys_collection_manager_util::howMuchSleepNeedFor(currentTime, latestExpiredAt, interval);
+    ASSERT_EQ(nextWakeupMillis, kRefreshIntervalIfErrored);
+}
+
 }  // namespace
 }  // namespace mongo