apache / apache/parquet-java

Page header uncompressed_page_size exceeds the actual decompressed payload by 2 bytes on ZSTD + dictionary-encoded ARRAY<ARRAY<BIGINT>> columns

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Type: bug
Dominant language
Java
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Description

### Describe the bug, including details regarding any error messages, version, and platform.

Summary

A corrupt Parquet file produced by a Spark writer (parquet-mr based, parquet 1.15.x, zstd-jni 1.5.2-1) contains data pages whose page header uncompressed_page_size is recorded 2 bytes larger than the bytes the decompressor actually produces. Reading
those pages throws EOFException at page decompression / level decoding time.

Environment

- Writer: Apache Spark (parquet-mr 1.15.2 vendored dependencies), ZSTD compression, dictionary encoding enabled (default).
- zstd-jni: 1.5.2-1 at write time (Spark). parquet 1.15.2 declares zstd-jni.version = 1.5.6-6.
- Reader: paimon vectorized reader (VectorizedColumnReader / VectorizedRleValuesReader) using parquet-mr 1.15.2, zstd-jni 1.5.7-6.
- Schema column: ARRAY> → leaf optional int64 element at path *.list.element.list.element, maxRepetitionLevel=2, maxDefinitionLevel=5, dictionary-encoded (PLAIN_DICTIONARY), V1 data pages (writer version PARQUET_1_0).

Error messages

Reading the affected page fails with:
org.apache.parquet.io.ParquetDecodingException: could not decompress page
at org.apache.parquet.hadoop.ColumnChunkPageReadStore$ColumnChunkPageReader$1.visit(ColumnChunkPageReadStore.java:212)
...
Caused by: java.io.EOFException
at java.base/java.io.DataInputStream.readFully(DataInputStream.java:202)
at org.apache.parquet.bytes.BytesInput$StreamBytesInput.toByteArray(BytesInput.java:399)
at org.apache.parquet.bytes.BytesInput.copy(BytesInput.java:205)
at org.apache.parquet.hadoop.CodecFactory$HeapBytesDecompressor.decompress(CodecFactory.java:178)
at org.apache.parquet.hadoop.ColumnChunkPageReadStore$ColumnChunkPageReader$1.visit(ColumnChunkPageReadStore.java:178)
After patching the header's uncompressed_page_size (3127 → 3125) so decompression succeeds, reading still fails, but inside level decoding:
java.io.EOFException
at org.apache.parquet.bytes.SingleBufferInputStream.sliceBuffers(SingleBufferInputStream.java:134)
at org.apache.parquet.bytes.ByteBufferInputStream.sliceStream(ByteBufferInputStream.java:116)
at org.apache.paimon.format.parquet.reader.VectorizedRleValuesReader.initFromPage(VectorizedRleValuesReader.java:108)
at org.apache.parquet.column.page.DataPageV1.accept(DataPageV1.java:134)

Reproducer / measurements

On the corrupt file (178 MB, 6 row groups, 1431 leaf columns), scanning every page by independently decoding the thrift PageHeader and decompressing the page body with zstd-jni directly (bypassing the reader), only 2 pages are affected, both identical
in shape:
- row group 4, column 139 (55.list.element.list.element), data page 5
- row group 4, column 141 (57.list.element.list.element), data page 1

Both report:
header uncompressed_page_size = 3127
header compressed_page_size = 1877
valueCount = 2898
rlEnc=RLE dlEnc=RLE valEnc=PLAIN_DICTIONARY
zstd actual decompressed bytes = 3125 (delta = +2)

Decompressing with zstd-jni 1.5.2-1 and 1.5.7-6 both yield 3125, so this is not a zstd-jni version artifact — the writer fed 3125 bytes to zstd but recorded 3127 in the header.
When I decompressed according to 3125 and read the page content, I found that the declared data length for the RLE part was 658, but the actual content length was 656. It seems that the RLE part output 2 bytes less

### Component(s)

Core

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with ColumnChunkPageReadStore and CodecFactory to trace page-size handling, then inspect DataPageV1 and VectorizedRleValuesReader for the RLE length mismatch. Reproduce the two affected ZSTD, dictionary-encoded nested-array pages described in the report. Done means those pages decompress and complete level decoding without EOFException, with the 2-byte discrepancy accounted for.

Written by the indexing model from the issue text.

Assessment

Tech stack
java, spark
Domain
data-engineering
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
48/100

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