This query does not show realtime metrics:

```
INSERT INTO wikistat WITH
    parseDateTimeBestEffort(extract(toLowCardinality(_path), 'pageviews-([\\d\\-]+)\\.gz$')) AS time,
    splitByChar(' ', line) AS values,
    splitByChar('.', values[1]) AS projects
SELECT
    time,
    projects[1] AS project,
    projects[2] AS subproject,
    values[2] AS path,
    CAST(values[3], 'UInt64') AS hits
FROM s3('https://....s3.eu-central-1.amazonaws.com/wikistat/original/*.gz', '...', '...', LineAsString, auto)
WHERE length(values) >= 3
```

Although this query does:

```
WITH
    parseDateTimeBestEffort(extract(toLowCardinality(_path), 'pageviews-([\\d\\-]+)\\.gz$')) AS time,
    splitByChar(' ', line) AS values,
    splitByChar('.', values[1]) AS projects
SELECT
    time,
    projects[1] AS project,
    projects[2] AS subproject,
    values[2] AS path,
    CAST(values[3], 'UInt64') AS hits
FROM s3('https://....s3.eu-central-1.amazonaws.com/wikistat/original/*.gz', '...', '...', LineAsString, auto)
WHERE length(values) >= 3
```

I also was not able to cancel the first query.
StorageHDFSPtr storage_,
    const StorageMetadataPtr & metadata_snapshot_,
    ContextPtr context_,
    UInt64 max_block_size_,
    bool need_path_column_,
    bool need_file_column_,
    std::shared_ptr<IteratorWrapper> file_iterator_,
    ColumnsDescription columns_description_)
    : SourceWithProgress(getBlockForSource(storage_, metadata_snapshot_, columns_description_, need_path_column_, need_file_column_))
    , WithContext(context_)
    , storage(std::move(storage_))
    , metadata_snapshot(metadata_snapshot_)
    , max_block_size(max_block_size_)
    , need_path_column(need_path_column_)
    , need_file_column(need_file_column_)
    , file_iterator(file_iterator_)
    , columns_description(std::move(columns_description_))
{
    initialize();
}
void HDFSSource::onCancel()
{
    std::lock_guard lock(reader_mutex);
    if (reader)
        reader->cancel();
}
bool HDFSSource::initialize()