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https://issues.apache.org/jira/browse/HADOOP-8761?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13448102#comment-13448102
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Andy Isaacson commented on HADOOP-8761:
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bq. True, it's incompatible yet correct behavior. I guess our options are
codify the bad behavior forever, or fix it now.
Since this is client-side code, we could do something like
# in 2.1.0, add %s and leave %b giving bytes, with a stderr message that %b
will change in a future release.
# in 2.2.0, change %b to give blocks and remove the stderr message.
bq. True, it's incompatible yet correct behavior.
I'm a little skeptical that "correct" with respect to POSIX stat(2) is
significant here. The "blocks" used in {{struct stat}} are very different from
the "blocks" in HDFS; POSIX blocks are fixed size, atomically written [1], and
the block size is a legacy feature (hardcoded to 512 bytes which is not the
underlying size of anything anymore). By contrast HDFS blocks are variable
size, nonatomic, and are much larger than POSIX blocks.
I agree that exposing the blocksize (and the blockcount) is a pretty valuable
feature, but there's a lot of caveats. Just off the top of my head: a single
file can have multiple blocksizes.
[1] blocks aren't guaranteed to be atomic by the POSIX spec AFAIK, but as a
practical matter modern implementations are atomic at some blocksize between
512 and 4096 bytes.
> Help for FsShell's Stat incorrectly mentions "file size in blocks" (should be
> bytes)
> ------------------------------------------------------------------------------------
>
> Key: HADOOP-8761
> URL: https://issues.apache.org/jira/browse/HADOOP-8761
> Project: Hadoop Common
> Issue Type: Bug
> Components: fs
> Affects Versions: 2.0.0-alpha
> Reporter: Philip Zeyliger
> Assignee: Philip Zeyliger
> Priority: Minor
> Attachments: HADOOP-8761.patch.txt
>
>
> Trivial patch attached corrects the usage information. Stat.java calls
> FileStatus.getLen(), which is most definitely the file size in bytes.
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