**Describe the bug**
```
5828589:2021.04.27 03:13:08.824665 [ 6101 ] {} <Trace> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Renaming temporary part tmp_merge_all_0_4_7_17 to all_0_4_7_17.
5828590:2021.04.27 03:13:08.824778 [ 3358 ] {} <Trace> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Renaming temporary part tmp_merge_all_0_4_7_17 to all_0_4_7_17.
5828591:2021.04.27 03:13:08.824823 [ 6101 ] {} <Warning> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Tried to add obsolete part all_0_4_7_17 covered by all_0_4_13_34 (state Committed)
5828623:2021.04.27 03:13:08.824951 [ 3358 ] {} <Warning> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Tried to add obsolete part all_0_4_7_17 covered by all_0_4_13_34 (state Committed)
5828624:2021.04.27 03:13:08.824995 [ 6101 ] {} <Warning> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94) (MergerMutator): Unexpected number of parts removed when adding all_0_4_7_17: 0 instead of 1
5828625:2021.04.27 03:13:08.825147 [ 3358 ] {} <Warning> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461) (MergerMutator): Unexpected number of parts removed when adding all_0_4_7_17: 0 instead of 1
5828643:2021.04.27 03:13:08.831273 [ 3358 ] {} <Trace> test_27.concurrent_alter_add_drop_2 (f0a064d0-dc89-4710-9781-a49bb0c16461): Trying to immediately remove part all_0_4_7_17 (state Temporary)
5828644:2021.04.27 03:13:08.831658 [ 3358 ] {} <Fatal> : Logical error: 'Part all_0_4_7_17 doesn't exist'.
5828648:2021.04.27 03:13:08.832767 [ 6101 ] {} <Trace> test_27.concurrent_alter_add_drop_3 (825021f7-129f-4841-ad6b-92215e3f1a94): Trying to immediately remove part all_0_4_7_17 (state Temporary)
5828649:2021.04.27 03:13:08.833210 [ 6101 ] {} <Fatal> : Logical error: 'Part all_0_4_7_17 doesn't exist'.

```

https://clickhouse-test-reports.s3.yandex.net/0/9bb4d8769f1064ada4cce6b26d8ff61c11356965/stress_test_(debug).html#fail1
LOG_DEBUG(log, "There are no data parts");
        return;
    }
    
    size_t num_threads = std::min(size_t(settings->max_part_loading_threads), part_names_with_disks.size());
    std::mutex mutex;
    DataPartsVector broken_parts_to_detach;
    size_t suspicious_broken_parts = 0;
    std::atomic<bool> has_adaptive_parts = false;
    std::atomic<bool> has_non_adaptive_parts = false;
    ThreadPool pool(num_threads);
    for (auto & part_names_with_disk : part_names_with_disks)
    {
        pool.scheduleOrThrowOnError([&]
        {
            const auto & part_name = part_names_with_disk.first;
            const auto part_disk_ptr = part_names_with_disk.second;
            MergeTreePartInfo part_info;
            if (!MergeTreePartInfo::tryParsePartName(part_name, &part_info, format_version))
                return;
            auto single_disk_volume = std::make_shared<SingleDiskVolume>("volume_" + part_name, part_disk_ptr, 0);
            auto part = createPart(part_name, part_info, single_disk_volume, part_name);
            bool broken = false;
            String part_path = fs::path(relative_data_path) / part_name;
            String marker_path = fs::path(part_path) / IMergeTreeDataPart::DELETE_ON_DESTROY_MARKER_FILE_NAME;
            if (part_disk_ptr->exists(marker_path))
            {
                LOG_WARNING(log, "Detaching stale part {}{}, which should have been deleted after a move. That can only happen after unclean restart of ClickHouse after move of a part having an operation blocking that stale copy of part.", getFullPathOnDisk(part_disk_ptr), part_name);
                std::lock_guard loading_lock(mutex);
                broken_parts_to_detach.push_back(part);