SERVER-39557 Migrate server parameters to IDL in src/mongo/db/logical_clock.cpp

5 files changed, 60 insertions, 34 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 699aaeb2f7e..3c5a584d5a1 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -1787,6 +1787,7 @@ env.Library(
     target='logical_clock',
     source=[
         'logical_clock.cpp',
+        env.Idlc('logical_clock.idl')[0],
     ],
     LIBDEPS=[
         'global_settings',
diff --git a/src/mongo/db/logical_clock.cpp b/src/mongo/db/logical_clock.cpp
index 4ca14daae32..8bf4a7e155c 100644
--- a/src/mongo/db/logical_clock.cpp
+++ b/src/mongo/db/logical_clock.cpp
@@ -32,6 +32,7 @@
 #include "mongo/platform/basic.h"
 
 #include "mongo/db/logical_clock.h"
+#include "mongo/db/logical_clock_gen.h"
 
 #include "mongo/base/status.h"
 #include "mongo/db/global_settings.h"
@@ -43,21 +44,6 @@
 
 namespace mongo {
 
-constexpr Seconds LogicalClock::kMaxAcceptableLogicalClockDriftSecs;
-
-MONGO_EXPORT_STARTUP_SERVER_PARAMETER(maxAcceptableLogicalClockDriftSecs,
-                                      long long,
-                                      LogicalClock::kMaxAcceptableLogicalClockDriftSecs.count())
-    ->withValidator([](const long long& potentialNewValue) {
-        if (potentialNewValue <= 0) {
-            return Status(ErrorCodes::BadValue,
-                          str::stream() << "maxAcceptableLogicalClockDriftSecs must be positive, "
-                                           "but attempted to set to: "
-                                        << potentialNewValue);
-        }
-        return Status::OK();
-    });
-
 namespace {
 const auto getLogicalClock = ServiceContext::declareDecoration<std::unique_ptr<LogicalClock>>();
 
@@ -173,7 +159,7 @@ void LogicalClock::setClusterTimeFromTrustedSource(LogicalTime newTime) {
 Status LogicalClock::_passesRateLimiter_inlock(LogicalTime newTime) {
     const unsigned wallClockSecs =
         durationCount<Seconds>(_service->getFastClockSource()->now().toDurationSinceEpoch());
-    auto maxAcceptableDriftSecs = static_cast<const unsigned>(maxAcceptableLogicalClockDriftSecs);
+    auto maxAcceptableDriftSecs = static_cast<const unsigned>(gMaxAcceptableLogicalClockDriftSecs);
     auto newTimeSecs = newTime.asTimestamp().getSecs();
 
     // Both values are unsigned, so compare them first to avoid wrap-around.
diff --git a/src/mongo/db/logical_clock.h b/src/mongo/db/logical_clock.h
index c40db592482..c6cebe983d8 100644
--- a/src/mongo/db/logical_clock.h
+++ b/src/mongo/db/logical_clock.h
@@ -49,9 +49,6 @@ public:
 
     static const uint32_t kMaxSignedInt = ((1U << 31) - 1);
 
-    static constexpr Seconds kMaxAcceptableLogicalClockDriftSecs =
-        Seconds(365 * 24 * 60 * 60);  // 1 year
-
     /**
      * Returns the current cluster time if this is a replica set node, otherwise returns a null
      * logical time.
diff --git a/src/mongo/db/logical_clock.idl b/src/mongo/db/logical_clock.idl
new file mode 100644
index 00000000000..18eb2e2b2ca
--- /dev/null
+++ b/src/mongo/db/logical_clock.idl
@@ -0,0 +1,41 @@
+#    Copyright (C) 2019-present MongoDB, Inc.
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the Server Side Public License, version 1,
+#    as published by MongoDB, Inc.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+#    Server Side Public License for more details.
+#
+#    You should have received a copy of the Server Side Public License
+#    along with this program. If not, see 
+#    <http://www.mongodb.com/licensing/server-side-public-license>.
+#
+#    As a special exception, the copyright holders give permission to link the 
+#    code of portions of this program with the OpenSSL library under certain
+#    conditions as described in each individual source file and distribute
+#    linked combinations including the program with the OpenSSL library. You 
+#    must comply with the Server Side Public License in all respects for 
+#    all of the code used other than as permitted herein. If you modify file(s)
+#    with this exception, you may extend this exception to your version of the 
+#    file(s), but you are not obligated to do so. If you do not wish to do so, 
+#    delete this exception statement from your version. If you delete this
+#    exception statement from all source files in the program, then also delete
+#    it in the license file.
+#
+
+global:
+    cpp_namespace: "mongo"
+
+server_parameters:
+    maxAcceptableLogicalClockDriftSecs:
+        description: "The value defines the maximum difference, in seconds, between the current clusterTime and a new clusterTime. Default value is 1 year."
+        set_at: [ startup ]
+        cpp_vartype: long long
+        cpp_varname: gMaxAcceptableLogicalClockDriftSecs
+        default: 
+            expr: (365 * 24 * 60 * 60) # one year
+        validator: 
+            gt: 0
\ No newline at end of file
diff --git a/src/mongo/db/logical_clock_test.cpp b/src/mongo/db/logical_clock_test.cpp
index 3b16ba9794f..ac3ddadd45d 100644
--- a/src/mongo/db/logical_clock_test.cpp
+++ b/src/mongo/db/logical_clock_test.cpp
@@ -35,6 +35,7 @@
 #include "mongo/bson/timestamp.h"
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/db/logical_clock.h"
+#include "mongo/db/logical_clock_gen.h"
 #include "mongo/db/logical_clock_test_fixture.h"
 #include "mongo/db/logical_time.h"
 #include "mongo/db/repl/replication_coordinator_mock.h"
@@ -110,7 +111,7 @@ TEST_F(LogicalClockTest, RateLimiterRejectsLogicalTimesTooFarAhead) {
 
     Timestamp tooFarAheadTimestamp(
         durationCount<Seconds>(getMockClockSourceTime().toDurationSinceEpoch()) +
-            durationCount<Seconds>(LogicalClock::kMaxAcceptableLogicalClockDriftSecs) +
+            kMaxAcceptableLogicalClockDriftSecsDefault +
             10,  // Add 10 seconds to ensure limit is exceeded.
         1);
     LogicalTime t1(tooFarAheadTimestamp);
@@ -120,12 +121,12 @@ TEST_F(LogicalClockTest, RateLimiterRejectsLogicalTimesTooFarAhead) {
 
 // Verify cluster time can be initialized to a very old time.
 TEST_F(LogicalClockTest, InitFromTrustedSourceCanAcceptVeryOldLogicalTime) {
-    setMockClockSourceTime(Date_t::fromMillisSinceEpoch(
-        durationCount<Seconds>(LogicalClock::kMaxAcceptableLogicalClockDriftSecs) * 10 * 1000));
+    setMockClockSourceTime(
+        Date_t::fromMillisSinceEpoch(kMaxAcceptableLogicalClockDriftSecsDefault * 10 * 1000));
 
     Timestamp veryOldTimestamp(
         durationCount<Seconds>(getMockClockSourceTime().toDurationSinceEpoch()) -
-        (durationCount<Seconds>(LogicalClock::kMaxAcceptableLogicalClockDriftSecs) * 5));
+        (kMaxAcceptableLogicalClockDriftSecsDefault * 5));
     auto veryOldTime = LogicalTime(veryOldTimestamp);
     getClock()->setClusterTimeFromTrustedSource(veryOldTime);
 
@@ -156,19 +157,19 @@ TEST_F(LogicalClockTest, WallClockSetTooFarInPast) {
     auto oneDay = Seconds(24 * 60 * 60);
 
     // Current wall clock and cluster time.
-    auto currentSecs = LogicalClock::kMaxAcceptableLogicalClockDriftSecs * 10;
+    auto currentSecs = Seconds(kMaxAcceptableLogicalClockDriftSecsDefault) * 10;
     LogicalTime currentTime(Timestamp(currentSecs, 0));
 
     // Set wall clock more than maxAcceptableLogicalClockDriftSecs seconds in the past.
-    auto pastSecs = currentSecs - LogicalClock::kMaxAcceptableLogicalClockDriftSecs - oneDay;
+    auto pastSecs = currentSecs - Seconds(kMaxAcceptableLogicalClockDriftSecsDefault) - oneDay;
     setMockClockSourceTime(Date_t::fromDurationSinceEpoch(pastSecs));
 
     // If cluster time is either uninitialized or even farther in the past, a write would set
     // cluster time more than maxAcceptableLogicalClockDriftSecs in the past.
     getDBClient()->insert(kDummyNamespaceString.ns(), BSON("x" << 1));
-    ASSERT_TRUE(
-        getClock()->getClusterTime() <
-        LogicalTime(Timestamp(currentSecs - LogicalClock::kMaxAcceptableLogicalClockDriftSecs, 0)));
+    ASSERT_TRUE(getClock()->getClusterTime() <
+                LogicalTime(Timestamp(
+                    currentSecs - Seconds(kMaxAcceptableLogicalClockDriftSecsDefault), 0)));
 
     // Set wall clock to the current time on the affected node.
     setMockClockSourceTime(Date_t::fromDurationSinceEpoch(currentSecs));
@@ -187,19 +188,19 @@ TEST_F(LogicalClockTest, WallClockSetTooFarInFuture) {
     auto oneDay = Seconds(24 * 60 * 60);
 
     // Current wall clock and cluster time.
-    auto currentSecs = LogicalClock::kMaxAcceptableLogicalClockDriftSecs * 10;
+    auto currentSecs = Seconds(kMaxAcceptableLogicalClockDriftSecsDefault) * 10;
     LogicalTime currentTime(Timestamp(currentSecs, 0));
 
     // Set wall clock more than maxAcceptableLogicalClockDriftSecs seconds in the future.
-    auto futureSecs = currentSecs + LogicalClock::kMaxAcceptableLogicalClockDriftSecs + oneDay;
+    auto futureSecs = currentSecs + Seconds(kMaxAcceptableLogicalClockDriftSecsDefault) + oneDay;
     setMockClockSourceTime(Date_t::fromDurationSinceEpoch(futureSecs));
 
     // A write gets through and advances cluster time more than maxAcceptableLogicalClockDriftSecs
     // in the future.
     getDBClient()->insert(kDummyNamespaceString.ns(), BSON("x" << 1));
-    ASSERT_TRUE(
-        getClock()->getClusterTime() >
-        LogicalTime(Timestamp(currentSecs + LogicalClock::kMaxAcceptableLogicalClockDriftSecs, 0)));
+    ASSERT_TRUE(getClock()->getClusterTime() >
+                LogicalTime(Timestamp(
+                    currentSecs + Seconds(kMaxAcceptableLogicalClockDriftSecsDefault), 0)));
 
     // Set wall clock to the current time on the affected node.
     setMockClockSourceTime(Date_t::fromDurationSinceEpoch(currentSecs));
@@ -325,7 +326,7 @@ TEST_F(LogicalClockTest, RejectsLogicalTimesGreaterThanMaxTime) {
     // The time can't be advanced through metadata to a time greater than the max possible.
     // Advance the wall clock close enough to the new value so the rate check is passed.
     auto almostMaxSecs =
-        Seconds(maxVal) - LogicalClock::kMaxAcceptableLogicalClockDriftSecs + Seconds(10);
+        Seconds(maxVal) - Seconds(kMaxAcceptableLogicalClockDriftSecsDefault) + Seconds(10);
     setMockClockSourceTime(Date_t::fromDurationSinceEpoch(almostMaxSecs));
     ASSERT_THROWS(getClock()->advanceClusterTime(beyondMaxTime), std::exception);
     ASSERT_TRUE(getClock()->getClusterTime() == LogicalTime());