[SPARK-14259][SQL] Add a FileSourceStrategy option for limiting #files in a partition #12068
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Test build #54536 has finished for PR 12068 at commit
|
Contributor
|
LGTM. I think there's more we can do here to bin pack a bit better (i.e. checking if small files can fit in existing partitions) but it would be good to get this in and have more experience with how to configure this. |
| isPublic = true) | ||
|
|
||
| val FILES_MAX_NUM_IN_PARTITION = longConf("spark.sql.files.maxNumInPartition", | ||
| defaultValue = Some(32), |
Contributor
There was a problem hiding this comment.
How is the default determined ?
Member
Author
There was a problem hiding this comment.
Currently, I have no reason to set this default value.
asfgit
pushed a commit
that referenced
this pull request
Apr 4, 2016
… opening ## What changes were proposed in this pull request? This PR basically re-do the things in #12068 but with a different model, which should work better in case of small files with different sizes. ## How was this patch tested? Updated existing tests. Ran a query on thousands of partitioned small files locally, with all default settings (the cost to open a file should be over estimated), the durations of tasks become smaller and smaller, which is good (the last few tasks will be shortest). Author: Davies Liu <davies@databricks.com> Closes #12095 from davies/file_cost.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
What changes were proposed in this pull request?
This pr is to add a config to control the maximum number of files as even small files have a non-trivial fixed cost. The current packing can put a lot of small files together which cases straggler tasks.
How was this patch tested?
I added tests to check if many files get split into partitions in FileSourceStrategySuite.