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https://issues.apache.org/jira/browse/HADOOP-16109?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16781137#comment-16781137
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Matt Foley commented on HADOOP-16109:
-------------------------------------
Yes, I'm thinking at
[https://github.com/apache/hadoop/blob/trunk/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AInputStream.java#L264]
we need
`&& diff < forwardSeekLimit;` instead of `<=`
What do you think?
The big question I have is, some of the text description talks about "reading
past the already active readahead range", i.e., past
`remainingInCurrentRequest`, as being a problem, but it seems to me that should
be okay; the problem documented so far is *seeking* past
`remainingInCurrentRequest` (specifically to exactly the end of CurrentRequest,
which is incorrectly guarded by the above L264 inequality) and then not doing a
stream close, which causes the problem. Do you know if, say, seeking to a few
bytes before the end of CurrentRequest, then reading past it (when the S3 file
does indeed have more to read), also causes an EOF, or does the stream
machinery handle that case correctly?
I'm putting together a test platform so I can answer such questions myself, but
it will take me a few hours; I haven't worked in s3a before.
> Parquet reading S3AFileSystem causes EOF
> ----------------------------------------
>
> Key: HADOOP-16109
> URL: https://issues.apache.org/jira/browse/HADOOP-16109
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 2.9.2, 2.8.5, 3.3.0, 3.1.2
> Reporter: Dave Christianson
> Assignee: Steve Loughran
> Priority: Blocker
>
> When using S3AFileSystem to read Parquet files a specific set of
> circumstances causes an EOFException that is not thrown when reading the
> same file from local disk
> Note this has only been observed under specific circumstances:
> - when the reader is doing a projection (will cause it to do a seek
> backwards and put the filesystem into random mode)
> - when the file is larger than the readahead buffer size
> - when the seek behavior of the Parquet reader causes the reader to seek
> towards the end of the current input stream without reopening, such that the
> next read on the currently open stream will read past the end of the
> currently open stream.
> Exception from Parquet reader is as follows:
> {code}
> Caused by: java.io.EOFException: Reached the end of stream with 51 bytes left
> to read
> at
> org.apache.parquet.io.DelegatingSeekableInputStream.readFully(DelegatingSeekableInputStream.java:104)
> at
> org.apache.parquet.io.DelegatingSeekableInputStream.readFullyHeapBuffer(DelegatingSeekableInputStream.java:127)
> at
> org.apache.parquet.io.DelegatingSeekableInputStream.readFully(DelegatingSeekableInputStream.java:91)
> at
> org.apache.parquet.hadoop.ParquetFileReader$ConsecutiveChunkList.readAll(ParquetFileReader.java:1174)
> at
> org.apache.parquet.hadoop.ParquetFileReader.readNextRowGroup(ParquetFileReader.java:805)
> at
> org.apache.parquet.hadoop.InternalParquetRecordReader.checkRead(InternalParquetRecordReader.java:127)
> at
> org.apache.parquet.hadoop.InternalParquetRecordReader.nextKeyValue(InternalParquetRecordReader.java:222)
> at
> org.apache.parquet.hadoop.ParquetRecordReader.nextKeyValue(ParquetRecordReader.java:207)
> at
> org.apache.flink.api.java.hadoop.mapreduce.HadoopInputFormatBase.fetchNext(HadoopInputFormatBase.java:206)
> at
> org.apache.flink.api.java.hadoop.mapreduce.HadoopInputFormatBase.reachedEnd(HadoopInputFormatBase.java:199)
> at
> org.apache.flink.runtime.operators.DataSourceTask.invoke(DataSourceTask.java:190)
> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:711)
> at java.lang.Thread.run(Thread.java:748)
> {code}
> The following example program generate the same root behavior (sans finding a
> Parquet file that happens to trigger this condition) by purposely reading
> past the already active readahead range on any file >= 1029 bytes in size..
> {code:java}
> final Configuration conf = new Configuration();
> conf.set("fs.s3a.readahead.range", "1K");
> conf.set("fs.s3a.experimental.input.fadvise", "random");
> final FileSystem fs = FileSystem.get(path.toUri(), conf);
> // forward seek reading across readahead boundary
> try (FSDataInputStream in = fs.open(path)) {
> final byte[] temp = new byte[5];
> in.readByte();
> in.readFully(1023, temp); // <-- works
> }
> // forward seek reading from end of readahead boundary
> try (FSDataInputStream in = fs.open(path)) {
> final byte[] temp = new byte[5];
> in.readByte();
> in.readFully(1024, temp); // <-- throws EOFException
> }
> {code}
>
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