And waits for them. That's pointless.
assert(prev_ptr == nullptr);
        getContext()->getInterserverIOHandler().addEndpoint(data_parts_exchange_ptr->getId(replica_path), data_parts_exchange_ptr);
        
        restarting_thread.start();
        
        startup_event.wait();
        
        
        background_executor.start();
        startBackgroundMovesIfNeeded();
        part_moves_between_shards_orchestrator.start();
    }
    catch (...)
    {
        
        
        
        try
        {
            shutdown();
        }
        catch (...)
        {
            std::terminate();
        }
        
        throw;
    }
}
void StorageReplicatedMergeTree::shutdown()