[ARROW-2842] [Python] Cannot read parquet files with row group size of 1 From HDFS

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Component/s: Python
• External issue URL: https://github.com/apache/arrow/issues/19217
• Assignee: Unassigned
• Reporter: Robbie Gruener
• Created: 12/Jul/18 21:53
• Updated: 11/Jan/23 07:23
• Resolved: 25/Jul/18 19:24

Description

This might be a bug in parquet-cpp, I need to spend a bit more time tracking this down but basically given a file with a single row on hdfs, reading it with pyarrow yields this error

```

TcpSocket.cpp: 79: HdfsEndOfStream: Read 8 bytes failed from: End of the stream
@ Unknown
@ Unknown
@ Unknown
@ Unknown
@ Unknown
@ Unknown
@ Unknown
@ Unknown
@ Unknown
@ arrow::io::HdfsReadableFile::ReadAt(long, long, long*, void*)
@ parquet::ArrowInputFile::ReadAt(long, long, unsigned char*)
@ parquet::SerializedFile::ParseMetaData()
@ parquet::ParquetFileReader::Contents::Open(std::unique_ptr<parquet::RandomAccessSource, std::default_delete<parquet::RandomAccessSource> >, parquet::ReaderProperties const&, std::shared_ptr<parquet::FileMetaData> const&)
@ parquet::ParquetFileReader::Open(std::unique_ptr<parquet::RandomAccessSource, std::default_delete<parquet::RandomAccessSource> >, parquet::ReaderProperties const&, std::shared_ptr<parquet::FileMetaData> const&)
@ parquet::arrow::OpenFile(std::shared_ptr<arrow::io::RandomAccessFile> const&, arrow::MemoryPool*, parquet::ReaderProperties const&, std::shared_ptr<parquet::FileMetaData> const&, std::unique_ptr<parquet::arrow::FileReader, std::default_delete<parquet::arrow::FileReader> >*)
@ __pyx_pw_7pyarrow_8_parquet_13ParquetReader_3open(_object*, _object*, _object*)

```

The following code causes it:

```

import pyarrow

import pyarrow.parquet as pq

 

fs = pyarrow.hdfs.connect('my-namenode-url', driver='libhdfs3') # fill in namenode information

file_object = fs.open('single-row.parquet') # update for hdfs path of file

pq.read_metadata(file_object) # this works

parquet_file = pq.ParquetFile(file_object)

parquet_file.read_row_group(0) # throws error

```

 

I am working on writing a unit test for this. Note that I am using libhdfs3.