For some reasons when we delete a MergeTree Part in atomic way something may go wrong - and leave the `delete_tmp_*` folder or it's part on disk. This may lead to a disk space consumption over time.

It's suggested to delete this folders at least at server start-up. Current solution with `clearOldTemporaryDirectories()` doesn't work because this method is called periodically from a thread without any locks or advisory on folders - it may cause the race conditions.
continue;
        }
        else
        {
            zkutil::KeeperMultiException::check(rc, ops, responses);
        }
    }
    ::sort(source_queue_names.begin(), source_queue_names.end());
    struct QueueEntryInfo
    {
        String data = {};
        Coordination::Stat stat = {};
        LogEntryPtr parsed_entry = {};
    };
    
    
    
    
    
    
    
    std::vector<QueueEntryInfo> source_queue;
    ActiveDataPartSet get_part_set{format_version};
    ActiveDataPartSet drop_range_set{format_version};
    {
        std::vector<zkutil::ZooKeeper::FutureGet> queue_get_futures;
        queue_get_futures.reserve(source_queue_names.size());
        for (const String & entry_name : source_queue_names)
            queue_get_futures.push_back(zookeeper->asyncTryGet(fs::path(source_path) / "queue" / entry_name));
        source_queue.reserve(source_queue_names.size());