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.
{
    String source_metadata_version_str;
    bool metadata_version_exists = zookeeper->tryGet(source_path + "/metadata_version", source_metadata_version_str);
    if (!metadata_version_exists)
    {
        
        
        LOG_WARNING(log, "Node {} does not exist. "
                         "Most likely it's because too old version of ClickHouse is running on replica {}. "
                         "Will not check metadata consistency",
                         source_path + "/metadata_version", source_replica);
        return;
    }
    Int32 source_metadata_version = parse<Int32>(source_metadata_version_str);
    if (metadata_version == source_metadata_version)
        return;