[
https://issues.apache.org/jira/browse/PARQUET-2106?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17453282#comment-17453282
]
ASF GitHub Bot commented on PARQUET-2106:
-----------------------------------------
alexeykudinkin opened a new pull request #940:
URL: https://github.com/apache/parquet-mr/pull/940
This refactors `BinaryComparator` to essentially avoid any allocations in
the routine of comparing 2 `Binary` objects.
More details could be found in
[PARQUET-2106](https://issues.apache.org/jira/browse/PARQUET-2106)
### Jira
- [ ] My PR addresses
[PARQUET-2106](https://issues.apache.org/jira/browse/PARQUET-2106) issues and
references them in the PR title. For example, "PARQUET-1234: My Parquet PR"
### Tests
- Does not need testing, since it's a simple refactoring that changes flows
that are already covered
### Commits
- [ ] My commits all reference Jira issues in their subject lines. In
addition, my commits follow the guidelines from "[How to write a good git
commit message](http://chris.beams.io/posts/git-commit/)":
1. Subject is separated from body by a blank line
1. Subject is limited to 50 characters (not including Jira issue reference)
1. Subject does not end with a period
1. Subject uses the imperative mood ("add", not "adding")
1. Body wraps at 72 characters
1. Body explains "what" and "why", not "how"
### Documentation
- [ ] In case of new functionality, my PR adds documentation that describes
how to use it.
- All the public functions and the classes in the PR contain Javadoc that
explain what it does
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
> BinaryComparator should avoid doing ByteBuffer.wrap in the hot-path
> -------------------------------------------------------------------
>
> Key: PARQUET-2106
> URL: https://issues.apache.org/jira/browse/PARQUET-2106
> Project: Parquet
> Issue Type: Task
> Components: parquet-mr
> Affects Versions: 1.12.2
> Reporter: Alexey Kudinkin
> Priority: Major
> Attachments: Screen Shot 2021-12-03 at 3.26.31 PM.png,
> profile_48449_alloc_1638494450_sort_by.html
>
>
> *Background*
> While writing out large Parquet tables using Spark, we've noticed that
> BinaryComparator is the source of substantial churn of extremely short-lived
> `HeapByteBuffer` objects – It's taking up to *16%* of total amount of
> allocations in our benchmarks, putting substantial pressure on a Garbage
> Collector:
> !Screen Shot 2021-12-03 at 3.26.31 PM.png|width=828,height=521!
> [^profile_48449_alloc_1638494450_sort_by.html]
>
> *Proposal*
> We're proposing to adjust lexicographical comparison (at least) to avoid
> doing any allocations, since this code lies on the hot-path of every Parquet
> write, therefore causing substantial churn amplification.
>
>
>
--
This message was sent by Atlassian Jira
(v8.20.1#820001)
