clear old range before apply snapshot (#4668) (#4715)

close #4414
pingcap · Jun 2, 2022 · 4eac5c3 · 4eac5c3
1 parent 18e9266
commit 4eac5c3
Showing 1 changed file with 16 additions and 3 deletions.
diff --git a/dbms/src/Storages/Transaction/ApplySnapshot.cpp b/dbms/src/Storages/Transaction/ApplySnapshot.cpp
@@ -166,17 +166,30 @@ void KVStore::onSnapshot(const RegionPtrWrap & new_region_wrap, RegionPtr old_re
                 // Acquire `drop_lock` so that no other threads can drop the storage. `alter_lock` is not required.
                 auto table_lock = storage->lockForShare(getThreadName());
                 auto dm_storage = std::dynamic_pointer_cast<StorageDeltaMerge>(storage);
-                auto key_range = DM::RowKeyRange::fromRegionRange(
+                auto new_key_range = DM::RowKeyRange::fromRegionRange(
                     new_region_wrap->getRange(), table_id, storage->isCommonHandle(), storage->getRowKeyColumnSize());
+                if (old_region)
+                {
+                    auto old_key_range = DM::RowKeyRange::fromRegionRange(
+                        old_region->getRange(), table_id, storage->isCommonHandle(), storage->getRowKeyColumnSize());
+                    if (old_key_range != new_key_range)
+                    {
+                        LOG_INFO(log,
+                            "clear region " << region_id << " old range " << old_key_range.toDebugString()
+                                            << " before apply snapshot of new range " << new_key_range.toDebugString());
+                        dm_storage->deleteRange(old_key_range, context.getSettingsRef());
+                    }
+                }
                 if constexpr (std::is_same_v<RegionPtrWrap, RegionPtrWithSnapshotFiles>)
                 {
                     // Call `ingestFiles` to delete data for range and ingest external DTFiles.
-                    dm_storage->ingestFiles(key_range, new_region_wrap.ingest_ids, /*clear_data_in_range=*/true, context.getSettingsRef());
+                    dm_storage->ingestFiles(
+                        new_key_range, new_region_wrap.ingest_ids, /*clear_data_in_range=*/true, context.getSettingsRef());
                 }
                 else
                 {
                     // Call `deleteRange` to delete data for range
-                    dm_storage->deleteRange(key_range, context.getSettingsRef());
+                    dm_storage->deleteRange(new_key_range, context.getSettingsRef());
                 }
             }
             catch (DB::Exception & e)