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.
void StorageReplicatedMergeTree::setZooKeeper()
{
    
    
    
    
    
    std::lock_guard lock(current_zookeeper_mutex);
    if (zookeeper_name == default_zookeeper_name)
    {
        current_zookeeper = getContext()->getZooKeeper();
    }
    else
    {
        current_zookeeper = getContext()->getAuxiliaryZooKeeper(zookeeper_name);
    }
}
zkutil::ZooKeeperPtr StorageReplicatedMergeTree::tryGetZooKeeper() const
{
    std::lock_guard lock(current_zookeeper_mutex);
    return current_zookeeper;
}
zkutil::ZooKeeperPtr StorageReplicatedMergeTree::getZooKeeper() const
{
    auto res = tryGetZooKeeper();
    if (!res)
        throw Exception("Cannot get ZooKeeper", ErrorCodes::NO_ZOOKEEPER);
    return res;
}
zkutil::ZooKeeperPtr StorageReplicatedMergeTree::getZooKeeperAndAssertNotReadonly() const