Github user ZunwenYou commented on the issue:
https://github.com/apache/spark/pull/17000
Hi, @MLnick
You are right, sliceAggregate splits an array into smaller chunks before
shuffle.
It has three advantage
Firstly, the shuffle data is less than treeAggregate during the whole
transformation operation.
Secondly, as your description, it allows more concurrency, not only during
the collect operation of driver, but also in the process of run **_seqOp_** and
**_combOp_**.
Thirdly, as I observed, when an record is larger than 1G Bit(an array of
100 million dimension), shuffle among executors becomes less efficiency. At the
same time, the rest of executos is waiting. I am not clear the reason for this.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
