Skip to content

[SPARK-28209][CORE][SHUFFLE] Proposed new shuffle writer API #25007

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
mccheah wants to merge 33 commits into from
Closed

[SPARK-28209][CORE][SHUFFLE] Proposed new shuffle writer API #25007

Changes from 1 commit
Commits
Show all changes
33 commits
Select commit Hold shift + click to select a range
1957e82
[SPARK-25299] Introduce the new shuffle writer API (#5) (#520)
mccheah Mar 20, 2019
857552a
[SPARK-25299] Local shuffle implementation of the shuffle writer API …
mccheah Apr 3, 2019
d13037f
[SPARK-25299] Make UnsafeShuffleWriter use the new API (#536)
mccheah Apr 17, 2019
8f5fb60
[SPARK-25299] Use the shuffle writer plugin for the SortShuffleWriter…
mccheah Apr 15, 2019
e17c7ea
[SPARK-25299] Shuffle locations api (#517)
mccheah Apr 19, 2019
3f0c131
[SPARK-25299] Move shuffle writers back to being given specific parti…
mccheah Apr 19, 2019
f982df7
[SPARK-25299] Don't set map status twice in bypass merge sort shuffle…
mccheah Apr 19, 2019
6891197
[SPARK-25299] Propose a new NIO transfer API for partition writing. (…
mccheah May 24, 2019
7b44ed2
Remove shuffle location support.
mccheah Jun 27, 2019
df75f1f
Remove changes to UnsafeShuffleWriter
mccheah Jun 27, 2019
a8558af
Revert changes for SortShuffleWriter
mccheah Jun 27, 2019
806d7bb
Revert a bunch of other stuff
mccheah Jun 27, 2019
3167030
More reverts
mccheah Jun 27, 2019
70f59db
Set task contexts in failing test
mccheah Jun 28, 2019
3083d86
Fix style
mccheah Jun 28, 2019
4c3d692
Check for null on the block manager as well.
mccheah Jun 28, 2019
2421c92
Add task attempt id in the APIs
mccheah Jul 1, 2019
982f207
Address comments
mccheah Jul 8, 2019
594d1e2
Fix style
mccheah Jul 8, 2019
66aae91
Address comments.
mccheah Jul 12, 2019
8b432f9
Merge remote-tracking branch 'origin/master' into spark-shuffle-write…
mccheah Jul 17, 2019
9f597dd
Address comments.
mccheah Jul 18, 2019
86c1829
Restructure test
mccheah Jul 18, 2019
a7885ae
Add ShuffleWriteMetricsReporter to the createMapOutputWriter API.
mccheah Jul 19, 2019
9893c6c
Add more documentation
mccheah Jul 19, 2019
cd897e7
REfactor reading records from file in test
mccheah Jul 19, 2019
9f17b9b
Address comments
mccheah Jul 24, 2019
e53a001
Code tags
mccheah Jul 24, 2019
56fa450
Add some docs
mccheah Jul 24, 2019
b8b7b8d
Change mockito format in BypassMergeSortShuffleWriterSuite
mccheah Jul 25, 2019
2d29404
Remove metrics from the API.
mccheah Jul 29, 2019
06ea01a
Address more comments.
mccheah Jul 29, 2019
7dceec9
Args per line
mccheah Jul 30, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
Add some docs
  • Loading branch information
@mccheah
mccheah committed Jul 24, 2019
commit 56fa450b4d703c7bc34f338e2ed0cd21fc82a98c
6 changes: 6 additions & 0 deletions core/src/main/java/org/apache/spark/shuffle/api/ShufflePartitionWriter.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -77,6 +77,12 @@ public interface ShufflePartitionWriter {
* <p>
* The default implementation should be sufficient for most situations. Only override this
Copy link
Contributor

@vanzin vanzin Jul 25, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Actually I'm not sure this is true, if the goal is to actually provide an optimization. In that case, the default implementation is only sufficient if your stream is a FileInputStream (just checked what Channels.newChannel() does).

Otherwise, the wrapper created will copy data into user memory, basically negating the optimization.

(Which maybe is an argument for returning null here and falling back to the normal IO path when that happens.)

Copy link
Contributor Author

@mccheah mccheah Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

What we're saying is that this kind of low-level optimization isn't the first place to look to improve performance most of the time, so to speak. So if one has to do the optimization, they should provide the proper override, but, the specific optimization isn't a critical factor to consider outside of the local disk implementation.

Copy link
Contributor

@vanzin vanzin Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

So why not follow my suggestion and return null here by default? It makes it much more clear that this implementation is not needed, and that by default the non-nio path is used.

Copy link
Contributor Author

@mccheah mccheah Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It's primarily to avoid returning null from the API - in that case I'd rather return Optional, then Optional.empty.

Copy link
Contributor

@vanzin vanzin Jul 29, 2019

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Sure. The main thing is returning something that indicates that this feature is not supported, instead of by default wrapping things a way that might actually hurt performance.

* method if there is a very specific optimization that needs to be built.
* <p>
* Note that the returned {@link WritableByteChannelWrapper} itself is closed, but not the
* underlying channel that is returned by {@link WritableByteChannelWrapper#channel()}. Ensure that
* the underlying channel is cleaned up in {@link WritableByteChannelWrapper#close()},
* {@link ShuffleMapOutputWriter#commitAllPartitions()}, or
* {@link ShuffleMapOutputWriter#abort(Throwable)}.
*/
default WritableByteChannelWrapper openChannelWrapper() throws IOException {
return new DefaultWritableByteChannelWrapper(Channels.newChannel(openStream()));
Expand Down