SERVER-74878 Restoring from query yield supports fetching point-in-time collections using UUIDs that are no longer in the latest CollectionCatalog

2 files changed, 59 insertions, 4 deletions

diff --git a/src/mongo/db/catalog/collection_catalog_test.cpp b/src/mongo/db/catalog/collection_catalog_test.cpp
index 343a10ae9f3..421e854969c 100644
--- a/src/mongo/db/catalog/collection_catalog_test.cpp
+++ b/src/mongo/db/catalog/collection_catalog_test.cpp
@@ -3669,5 +3669,42 @@ TEST_F(CollectionCatalogTimestampTest, OpenCollectionBetweenIndexBuildInProgress
             coll);
     }
 }
+
+TEST_F(CollectionCatalogTimestampTest, ResolveNamespaceStringOrUUIDAtLatest) {
+    RAIIServerParameterControllerForTest featureFlagController(
+        "featureFlagPointInTimeCatalogLookups", true);
+
+    const NamespaceString nss = NamespaceString::createNamespaceString_forTest("a.b");
+    const Timestamp createCollectionTs = Timestamp(10, 10);
+    const UUID uuid = createCollection(opCtx.get(), nss, createCollectionTs);
+    const NamespaceStringOrUUID nssOrUUID = NamespaceStringOrUUID(nss.db(), uuid);
+
+    NamespaceString resolvedNss =
+        CollectionCatalog::get(opCtx.get())->resolveNamespaceStringOrUUID(opCtx.get(), nssOrUUID);
+    ASSERT_EQ(resolvedNss, nss);
+
+    const Timestamp dropCollectionTs = Timestamp(20, 20);
+    dropCollection(opCtx.get(), nss, dropCollectionTs);
+
+    // Resolving the UUID throws NamespaceNotFound as the collection is no longer in the latest
+    // collection catalog.
+    ASSERT_THROWS_CODE(
+        CollectionCatalog::get(opCtx.get())->resolveNamespaceStringOrUUID(opCtx.get(), nssOrUUID),
+        DBException,
+        ErrorCodes::NamespaceNotFound);
+
+    {
+        OneOffRead oor(opCtx.get(), createCollectionTs);
+        Lock::GlobalLock globalLock(opCtx.get(), MODE_IS);
+
+        CollectionCatalog::get(opCtx.get())
+            ->establishConsistentCollection(opCtx.get(), nss, createCollectionTs);
+
+        // Resolving the UUID looks in OpenedCollections to try to resolve the UUID.
+        resolvedNss = CollectionCatalog::get(opCtx.get())
+                          ->resolveNamespaceStringOrUUID(opCtx.get(), nssOrUUID);
+        ASSERT_EQ(resolvedNss, nss);
+    }
+}
 }  // namespace
 }  // namespace mongo
diff --git a/src/mongo/db/db_raii.cpp b/src/mongo/db/db_raii.cpp
index 4d65ddeba24..f9d8bb2e446 100644
--- a/src/mongo/db/db_raii.cpp
+++ b/src/mongo/db/db_raii.cpp
@@ -1084,10 +1084,28 @@ ConsistentCatalogAndSnapshot getConsistentCatalogAndSnapshot(
 
         const auto catalogBeforeSnapshot = CollectionCatalog::get(opCtx);
 
-        // It is incorrect to resolve the UUID here as we haven't established a consistent view of
-        // this UUID yet. During a concurrent rename it can be wrong. This namespace is only used to
-        // determine if it is an internal namespace.
-        const auto nss = catalogBeforeSnapshot->resolveNamespaceStringOrUUID(opCtx, nsOrUUID);
+        // When a query yields it releases its snapshot, and any point-in-time instantiated
+        // collections stored on the snapshot decoration are destructed. At the start of a query,
+        // collections are fetched using a namespace. However, when a query is restoring from
+        // yield it attempts to fetch collections by UUID. It's possible for a UUID to no longer
+        // resolve to a namespace in the latest collection catalog if that collection was dropped
+        // while the query was yielding. This doesn't conclude that the collection is inaccessible
+        // at an earlier point-in-time as the data files may still be on disk. This namespace is
+        // used to determine if the read source needs to be changed and we only do this if the
+        // original read source is kNoTimestamp or kLastApplied. If it's neither of the two we can
+        // safely continue.
+        NamespaceString nss;
+        try {
+            nss = catalogBeforeSnapshot->resolveNamespaceStringOrUUID(opCtx, nsOrUUID);
+        } catch (const ExceptionFor<ErrorCodes::NamespaceNotFound>&) {
+            invariant(nsOrUUID.uuid());
+
+            const auto readSource = opCtx->recoveryUnit()->getTimestampReadSource();
+            if (readSource == RecoveryUnit::ReadSource::kNoTimestamp ||
+                readSource == RecoveryUnit::ReadSource::kLastApplied) {
+                throw;
+            }
+        }
 
         // This may modify the read source on the recovery unit for opCtx if the current read source
         // is either kNoTimestamp or kLastApplied.