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https://issues.apache.org/jira/browse/PARQUET-860?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16370458#comment-16370458
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Ryan Blue commented on PARQUET-860:
-----------------------------------
The S3 file system implementation should retry and recover if it is a transient
error. In general I'm skeptical that Parquet can reliably provide what you want.
Parquet makes no guarantee of durability until the close operation returns. As
a consequence, you should not discard incoming records until then. This is why
Parquet works better with systems like Kafka that have a long window of time
where records can be replayed. In general, I would not recommend Parquet as a
format from other streaming systems like Flume. This works fine with MR or
Spark where the framework itself will retry a write task when an output writer
throws an exception.
> ParquetWriter.getDataSize NullPointerException after closed
> -----------------------------------------------------------
>
> Key: PARQUET-860
> URL: https://issues.apache.org/jira/browse/PARQUET-860
> Project: Parquet
> Issue Type: Bug
> Components: parquet-mr
> Affects Versions: 1.9.0
> Environment: Linux prim 4.8.13-1-ARCH #1 SMP PREEMPT Fri Dec 9
> 07:24:34 CET 2016 x86_64 GNU/Linux
> openjdk version "1.8.0_112"
> OpenJDK Runtime Environment (build 1.8.0_112-b15)
> OpenJDK 64-Bit Server VM (build 25.112-b15, mixed mode)
> Reporter: Mike Mintz
> Priority: Major
>
> When I run {{ParquetWriter.getDataSize()}}, it works normally. But after I
> call {{ParquetWriter.close()}}, subsequent calls to ParquetWriter.getDataSize
> result in a NullPointerException.
> {noformat}
> java.lang.NullPointerException
> at
> org.apache.parquet.hadoop.InternalParquetRecordWriter.getDataSize(InternalParquetRecordWriter.java:132)
> at
> org.apache.parquet.hadoop.ParquetWriter.getDataSize(ParquetWriter.java:314)
> at FileBufferState.getFileSizeInBytes(FileBufferState.scala:83)
> {noformat}
> The reason for the NPE appears to be in
> {{InternalParquetRecordWriter.getDataSize}}, where it assumes that
> {{columnStore}} is not null.
> But the {{close()}} method calls {{flushRowGroupToStore()}} which sets
> {{columnStore = null}}.
> I'm guessing that once the file is closed, we can just return
> {{lastRowGroupEndPos}} since there should be no more buffered data, but I
> don't fully understand how this class works.
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