SERVER-37568 computeAtClusterTimeForOneShard should always return the latest logical clock time

2 files changed, 13 insertions, 24 deletions

diff --git a/src/mongo/s/at_cluster_time_util.cpp b/src/mongo/s/at_cluster_time_util.cpp
index 1ace3e9dc40..3a44e50923d 100644
--- a/src/mongo/s/at_cluster_time_util.cpp
+++ b/src/mongo/s/at_cluster_time_util.cpp
@@ -49,7 +49,8 @@ LogicalTime _computeAtClusterTime(OperationContext* opCtx,
                                   const NamespaceString& nss,
                                   const BSONObj query,
                                   const BSONObj collation) {
-    // TODO: SERVER-31767
+    // TODO SERVER-36312: Re-enable algorithm using the cached opTimes of the targeted shards.
+    // TODO SERVER-37549: Use the shard's cached lastApplied opTime instead of lastCommitted.
     return LogicalClock::get(opCtx)->getClusterTime();
 }
 }  // namespace
@@ -122,19 +123,9 @@ boost::optional<LogicalTime> computeAtClusterTimeForOneShard(OperationContext* o
         return boost::none;
     }
 
-    auto shardRegistry = Grid::get(opCtx)->shardRegistry();
-    invariant(shardRegistry);
-
-    auto shard = shardRegistry->getShardNoReload(shardId);
-    uassert(ErrorCodes::ShardNotFound, str::stream() << "Could not find shard " << shardId, shard);
-
-    // Return the cached last committed opTime for the shard if there is one, otherwise return the
-    // latest cluster time from the logical clock.
-    auto lastCommittedOpTime = shard->getLastCommittedOpTime();
-
-    auto atClusterTime = lastCommittedOpTime != LogicalTime::kUninitialized
-        ? lastCommittedOpTime
-        : LogicalClock::get(opCtx)->getClusterTime();
+    // TODO SERVER-36312: Re-enable algorithm using the cached opTimes of the targeted shard.
+    // TODO SERVER-37549: Use the shard's cached lastApplied opTime instead of lastCommitted.
+    auto atClusterTime = LogicalClock::get(opCtx)->getClusterTime();
 
     // If the user passed afterClusterTime, atClusterTime must be greater than or equal to it.
     const auto afterClusterTime = repl::ReadConcernArgs::get(opCtx).getArgsAfterClusterTime();
diff --git a/src/mongo/s/compute_at_cluster_time_test.cpp b/src/mongo/s/compute_at_cluster_time_test.cpp
index 088ad79da2c..be93abf9103 100644
--- a/src/mongo/s/compute_at_cluster_time_test.cpp
+++ b/src/mongo/s/compute_at_cluster_time_test.cpp
@@ -91,7 +91,7 @@ TEST_F(AtClusterTimeTest, ComputeValidValid) {
 
     auto maxTime = at_cluster_time_util::computeAtClusterTime(
         operationContext(), true, {shardOneId, shardTwoId}, kNss, kEmptyQuery, kEmptyCollation);
-    // TODO: SERVER-31767
+    // TODO: SERVER-36312
     // ASSERT_EQ(*maxTime, timeTwo);
     ASSERT_EQ(*maxTime, kInMemoryLogicalTime);
 }
@@ -107,7 +107,7 @@ TEST_F(AtClusterTimeTest, ComputeValidInvalid) {
 
     auto maxTime = at_cluster_time_util::computeAtClusterTime(
         operationContext(), true, {shardOneId, shardTwoId}, kNss, kEmptyQuery, kEmptyCollation);
-    // TODO: SERVER-31767
+    // TODO: SERVER-36312
     // ASSERT_EQ(*maxTime, timeTwo);
     ASSERT_EQ(*maxTime, kInMemoryLogicalTime);
 }
@@ -133,7 +133,9 @@ TEST_F(AtClusterTimeTest, ComputeForOneShard) {
 
     auto atClusterTime =
         at_cluster_time_util::computeAtClusterTimeForOneShard(operationContext(), shardOneId);
-    ASSERT_EQ(*atClusterTime, timeOne);
+    // TODO SERVER-36312
+    // ASSERT_EQ(*atClusterTime, timeOne);
+    ASSERT_EQ(*atClusterTime, kInMemoryLogicalTime);
 }
 
 TEST_F(AtClusterTimeTest, ComputeForOneShardNoCachedOpTime) {
@@ -145,12 +147,8 @@ TEST_F(AtClusterTimeTest, ComputeForOneShardNoCachedOpTime) {
     ASSERT_EQ(*atClusterTime, kInMemoryLogicalTime);
 }
 
-TEST_F(AtClusterTimeTest, ComputeForOneShardNoShard) {
-    ASSERT_THROWS_CODE(at_cluster_time_util::computeAtClusterTimeForOneShard(operationContext(),
-                                                                             ShardId("fakeShard")),
-                       AssertionException,
-                       ErrorCodes::ShardNotFound);
-}
+// TODO SERVER-36312: Verify computing atClusterTime for a single shard that does not exist returns
+// an error.
 
 class AtClusterTimeTargetingTest : public CatalogCacheTestFixture {
 protected:
@@ -203,7 +201,7 @@ TEST_F(AtClusterTimeTargetingTest, ReturnsLatestTimeFromShard) {
 
     repl::ReadConcernArgs::get(operationContext()) =
         repl::ReadConcernArgs(repl::ReadConcernLevel::kSnapshotReadConcern);
-    // TODO: SERVER-31767
+    // TODO: SERVER-36312
     // ASSERT_EQ(time2,
     //           *at_cluster_time_util::computeAtClusterTime(operationContext(), true, shards, kNss,
     //           query, collation));