SERVER-55113 Split rename/range-deletion procedures in idempotent steps

5 files changed, 70 insertions, 20 deletions

diff --git a/src/mongo/db/namespace_string.cpp b/src/mongo/db/namespace_string.cpp
index ae08e4c640c..352d65311f4 100644
--- a/src/mongo/db/namespace_string.cpp
+++ b/src/mongo/db/namespace_string.cpp
@@ -93,6 +93,8 @@ const NamespaceString NamespaceString::kIndexBuildEntryNamespace(NamespaceString
                                                                  "system.indexBuilds");
 const NamespaceString NamespaceString::kRangeDeletionNamespace(NamespaceString::kConfigDb,
                                                                "rangeDeletions");
+const NamespaceString NamespaceString::kRangeDeletionForRenameNamespace(NamespaceString::kConfigDb,
+                                                                        "rangeDeletionsForRename");
 const NamespaceString NamespaceString::kConfigReshardingOperationsNamespace(
     NamespaceString::kConfigDb, "reshardingOperations");
 
diff --git a/src/mongo/db/namespace_string.h b/src/mongo/db/namespace_string.h
index 02265c9641a..b0558eea4a8 100644
--- a/src/mongo/db/namespace_string.h
+++ b/src/mongo/db/namespace_string.h
@@ -141,6 +141,9 @@ public:
     // Namespace for pending range deletions.
     static const NamespaceString kRangeDeletionNamespace;
 
+    // Namespace containing pending range deletions snapshots for rename operations.
+    static const NamespaceString kRangeDeletionForRenameNamespace;
+
     // Namespace for the coordinator's resharding operation state.
     static const NamespaceString kConfigReshardingOperationsNamespace;
 
diff --git a/src/mongo/db/s/range_deletion_util.cpp b/src/mongo/db/s/range_deletion_util.cpp
index 599fa90d6a4..03a1b3a1540 100644
--- a/src/mongo/db/s/range_deletion_util.cpp
+++ b/src/mongo/db/s/range_deletion_util.cpp
@@ -411,8 +411,6 @@ ExecutorFuture<void> waitForDeletionsToMajorityReplicate(
     });
 }
 
-}  // namespace
-
 std::vector<RangeDeletionTask> getPersistentRangeDeletionTasks(OperationContext* opCtx,
                                                                const NamespaceString& nss) {
     std::vector<RangeDeletionTask> tasks;
@@ -428,17 +426,51 @@ std::vector<RangeDeletionTask> getPersistentRangeDeletionTasks(OperationContext*
     return tasks;
 }
 
-void storeRangeDeletionTasks(OperationContext* opCtx, std::vector<RangeDeletionTask>& tasks) {
-    PersistentTaskStore<RangeDeletionTask> store(NamespaceString::kRangeDeletionNamespace);
-    for (const auto& deletionTask : tasks) {
-        store.add(opCtx, deletionTask);
+}  // namespace
+
+void snapshotRangeDeletionsForRename(OperationContext* opCtx,
+                                     const NamespaceString& fromNss,
+                                     const NamespaceString& toNss) {
+    auto rangeDeletionTasks = getPersistentRangeDeletionTasks(opCtx, fromNss);
+    PersistentTaskStore<RangeDeletionTask> store(NamespaceString::kRangeDeletionForRenameNamespace);
+    for (auto& task : rangeDeletionTasks) {
+        task.setNss(toNss);  // Associate task to the new namespace
+        store.add(opCtx, task);
     }
 }
 
-void deleteRangeDeletionTasks(OperationContext* opCtx, const NamespaceString& nss) {
-    PersistentTaskStore<RangeDeletionTask> store(NamespaceString::kRangeDeletionNamespace);
+void restoreRangeDeletionTasksForRename(OperationContext* opCtx, const NamespaceString& nss) {
+    PersistentTaskStore<RangeDeletionTask> rangeDeletionsForRenameStore(
+        NamespaceString::kRangeDeletionForRenameNamespace);
+    PersistentTaskStore<RangeDeletionTask> rangeDeletionsStore(
+        NamespaceString::kRangeDeletionNamespace);
+
     const auto query = QUERY(RangeDeletionTask::kNssFieldName << nss.ns());
-    store.remove(opCtx, query);
+
+    // Remove eventual leftovers from a previously uncompleted restore
+    rangeDeletionsStore.remove(opCtx, query);
+
+    rangeDeletionsForRenameStore.forEach(opCtx, query, [&](const RangeDeletionTask& deletionTask) {
+        auto task = deletionTask;
+        task.setId(UUID::gen());  // Assign a new id to prevent duplicate key errors
+        rangeDeletionsStore.add(opCtx, task);
+        return true;
+    });
+}
+
+void deleteRangeDeletionTasksForRename(OperationContext* opCtx,
+                                       const NamespaceString& fromNss,
+                                       const NamespaceString& toNss) {
+    // Delete range deletion tasks associated to the source collection
+    PersistentTaskStore<RangeDeletionTask> rangeDeletionsStore(
+        NamespaceString::kRangeDeletionNamespace);
+    rangeDeletionsStore.remove(opCtx, QUERY(RangeDeletionTask::kNssFieldName << fromNss.ns()));
+
+    // Delete already restored snapshots associated to the target collection
+    PersistentTaskStore<RangeDeletionTask> rangeDeletionsForRenameStore(
+        NamespaceString::kRangeDeletionForRenameNamespace);
+    rangeDeletionsForRenameStore.remove(opCtx,
+                                        QUERY(RangeDeletionTask::kNssFieldName << toNss.ns()));
 }
 
 
diff --git a/src/mongo/db/s/range_deletion_util.h b/src/mongo/db/s/range_deletion_util.h
index 6045975a293..bff30e76299 100644
--- a/src/mongo/db/s/range_deletion_util.h
+++ b/src/mongo/db/s/range_deletion_util.h
@@ -76,10 +76,27 @@ SharedSemiFuture<void> removeDocumentsInRange(
     Seconds delayForActiveQueriesOnSecondariesToComplete,
     Milliseconds delayBetweenBatches);
 
-std::vector<RangeDeletionTask> getPersistentRangeDeletionTasks(OperationContext* opCtx,
-                                                               const NamespaceString& nss);
-void storeRangeDeletionTasks(OperationContext* opCtx, std::vector<RangeDeletionTask>& tasks);
+/**
+ * - Retrieves source collection's persistent range deletion tasks from `config.rangeDeletions`
+ * - Associates tasks to the target collection
+ * - Stores tasks in `config.rangeDeletionsForRename`
+ */
+void snapshotRangeDeletionsForRename(OperationContext* opCtx,
+                                     const NamespaceString& fromNss,
+                                     const NamespaceString& toNss);
 
-void deleteRangeDeletionTasks(OperationContext* opCtx, const NamespaceString& nss);
+/**
+ * Copies `config.rangeDeletionsForRename` tasks for the specified namespace to
+ * `config.rangeDeletions`.
+ */
+void restoreRangeDeletionTasksForRename(OperationContext* opCtx, const NamespaceString& nss);
+
+/**
+ * - Deletes range deletion tasks for the FROM namespace from `config.rangeDeletions`.
+ * - Deletes range deletion tasks for the TO namespace from `config.rangeDeletionsForRename`
+ */
+void deleteRangeDeletionTasksForRename(OperationContext* opCtx,
+                                       const NamespaceString& fromNss,
+                                       const NamespaceString& toNss);
 
 }  // namespace mongo
diff --git a/src/mongo/db/s/shardsvr_rename_collection_participant_command.cpp b/src/mongo/db/s/shardsvr_rename_collection_participant_command.cpp
index fcf9da184b7..c0833d662db 100644
--- a/src/mongo/db/s/shardsvr_rename_collection_participant_command.cpp
+++ b/src/mongo/db/s/shardsvr_rename_collection_participant_command.cpp
@@ -109,19 +109,15 @@ public:
             dropCollectionLocally(opCtx, toNss);
 
             try {
-                auto rangeDeletionTasks = getPersistentRangeDeletionTasks(opCtx, fromNss);
+                snapshotRangeDeletionsForRename(opCtx, fromNss, toNss);
 
                 // Rename the collection locally and clear the cache
                 validateAndRunRenameCollection(opCtx, fromNss, toNss, options);
                 uassertStatusOK(
                     shardmetadatautil::dropChunksAndDeleteCollectionsEntry(opCtx, fromNss));
 
-                deleteRangeDeletionTasks(opCtx, toNss);
-                for (auto& task : rangeDeletionTasks) {
-                    task.setId(UUID::gen());
-                    task.setNss(toNss);
-                }
-                storeRangeDeletionTasks(opCtx, rangeDeletionTasks);
+                restoreRangeDeletionTasksForRename(opCtx, toNss);
+                deleteRangeDeletionTasksForRename(opCtx, fromNss, toNss);
             } catch (ExceptionFor<ErrorCodes::NamespaceNotFound>&) {
                 // It's ok for a participant shard to have no knowledge about a collection
                 LOGV2_DEBUG(