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https://issues.apache.org/jira/browse/ARROW-17984?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17625816#comment-17625816
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Ziheng Wang commented on ARROW-17984:
-------------------------------------
I have attached a crash file. You can unpack using apport-unpack, and then gdb
the CoreDump with gdb `cat ExecutablePath` CoreDump. Once inside the gdb do
{color:#e01e5a}thread apply all bt{color}
> pq.read_table doesn't seem to be thread safe
> --------------------------------------------
>
> Key: ARROW-17984
> URL: https://issues.apache.org/jira/browse/ARROW-17984
> Project: Apache Arrow
> Issue Type: Bug
> Components: Parquet
> Affects Versions: 9.0.0
> Reporter: Ziheng Wang
> Priority: Major
> Attachments: _usr_bin_python3.8.1000.crash
>
>
> Before PR: [https://github.com/apache/arrow/pull/13799] gets merged in
> master, I am using multithreading to improve read bandwidth from S3. Even
> after that PR gets merged, I probably will still try to use multithreading to
> some extent.
> However pq.read_table from S3 doesn't seem to be thread safe. Seems like it
> uses the new dataset reader under the hood. I cannot provide a reproduction,
> not a stable one anyway. But this is roughly the script I have been using
> ~~~
> def get_next_batch(self, mapper_id, pos=None):
> def download(file):
> return pq.read_table("s3://" + self.bucket + "/" + file,
> columns=self.columns, filters=self.filters)
>
> executor = concurrent.futures.ThreadPoolExecutor(max_workers=self.workers)
> futures= \{executor.submit(download, file): file for file in my_files}
> for future inconcurrent.futures.as_completed(futures):
> yield future.result()
> ~~~
> The errors all have to do with malloc segfaults which makes me suspect the
> connection object is being reused across different pq.read_table invocations
> in different threads
> ```
> (InputReaderNode pid=25001, ip=172.31.60.29) malloc_consolidate(): invalid
> chunk size
> (InputReaderNode pid=25001, ip=172.31.60.29) *** SIGABRT received at
> time=1665464922 on cpu 9 ***
> (InputReaderNode pid=25001, ip=172.31.60.29) PC: @ 0x7f9a480a803b
> (unknown) raise
> (InputReaderNode pid=25001, ip=172.31.60.29) @ 0x7f9a480a80c0
> 4160 (unknown)
> (InputReaderNode pid=25001, ip=172.31.60.29) @ 0x7f9a480fa32c
> (unknown) (unknown)
> ```
> Note, this multithreaded code is running inside a Ray actor process, but that
> shouldn't be a problem.
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