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.
}
                }
            }
            if (replica.empty())
            {
                ProfileEvents::increment(ProfileEvents::ReplicatedPartFailedFetches);
                if (!need_to_check_missing_part)
                    return false;
                throw Exception("No active replica has part " + entry.new_part_name + " or covering part", ErrorCodes::NO_REPLICA_HAS_PART);
            }
        }
        try
        {
            String part_name = entry.actual_new_part_name.empty() ? entry.new_part_name : entry.actual_new_part_name;
            if (!entry.actual_new_part_name.empty())
                LOG_DEBUG(log, "Will fetch part {} instead of {}", entry.actual_new_part_name, entry.new_part_name);
            if (!fetchPart(part_name, metadata_snapshot, fs::path(zookeeper_path) / "replicas" / replica, false, entry.quorum))
                return false;
        }
        catch (Exception & e)
        {
            
            if (e.code() == ErrorCodes::RECEIVED_ERROR_TOO_MANY_REQUESTS)
                e.addMessage("Too busy replica. Will try later.");
            throw;
        }
        if (entry.type == LogEntry::MERGE_PARTS)
            ProfileEvents::increment(ProfileEvents::ReplicatedPartFetchesOfMerged);
    }
    catch (...)