[
https://issues.apache.org/jira/browse/HDFS-13752?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16584480#comment-16584480
]
Misha Dmitriev commented on HDFS-13752:
---------------------------------------
[~b.maidics] thank you, from my prospective this looks good/expected. The
performance difference in small and is even slightly in favor of the new code.
One other possible explanation for that is reduced GC time because you use less
memory, especially in the Old Gen.
[~xiaochen] [~jojochuang] can you take a look as well? I think at this point
you have enough information to decide on whether to greenlight this change.
> fs.Path stores file path in java.net.URI causes big memory waste
> ----------------------------------------------------------------
>
> Key: HDFS-13752
> URL: https://issues.apache.org/jira/browse/HDFS-13752
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: fs
> Affects Versions: 2.7.6
> Environment: Hive 2.1.1 and hadoop 2.7.6
> Reporter: Barnabas Maidics
> Priority: Major
> Attachments: Screen Shot 2018-07-20 at 11.12.38.png,
> heapdump-100000partitions.html, measurement.pdf
>
>
> I was looking at HiveServer2 memory usage, and a big percentage of this was
> because of org.apache.hadoop.fs.Path, where you store file paths in a
> java.net.URI object. The URI implementation stores the same string in 3
> different objects (see the attached image). In Hive when there are many
> partitions this cause a big memory usage. In my particular case 42% of memory
> was used by java.net.URI so it could be reduced to 14%.
> I wonder if the community is open to replace it with a more memory efficient
> implementation and what other things should be considered here? It can be a
> huge memory improvement for Hadoop and for Hive as well.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
