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https://issues.apache.org/jira/browse/HADOOP-14943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16364706#comment-16364706
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Steve Loughran commented on HADOOP-14943:
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if you return a specific host for the data, then it reports to the scheduler
the preferred location of the work...the schedulers will try and place the work
there and wait a bit before giving up. What you are measuring there is how long
spark waits before rescheduling
You don't want location affinity in object stores, not really ... though
[~ehiggs] and [~Thomas Demoor] might have different data
> Add common getFileBlockLocations() emulation for object stores, including S3A
> -----------------------------------------------------------------------------
>
> Key: HADOOP-14943
> URL: https://issues.apache.org/jira/browse/HADOOP-14943
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 2.8.1
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Major
> Attachments: HADOOP-14943-001.patch, HADOOP-14943-002.patch,
> HADOOP-14943-002.patch, HADOOP-14943-003.patch, HADOOP-14943-004.patch
>
>
> It looks suspiciously like S3A isn't providing the partitioning data needed
> in {{listLocatedStatus}} and {{getFileBlockLocations()}} needed to break up a
> file by the blocksize. This will stop tools using the MRv1 APIS doing the
> partitioning properly if the input format isn't doing it own split logic.
> FileInputFormat in MRv2 is a bit more configurable about input split
> calculation & will split up large files. but otherwise, the partitioning is
> being done more by the default values of the executing engine, rather than
> any config data from the filesystem about what its "block size" is,
> NativeAzureFS does a better job; maybe that could be factored out to
> hadoop-common and reused?
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