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https://issues.apache.org/jira/browse/HDFS-8833?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14718396#comment-14718396
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Walter Su commented on HDFS-8833:
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>..."encode replication and ecPolicy together" (Zhe Zhang)
Good Thought Zhe!
>... Well it depends on how small (in relative to cell size). We should
>certainly skip files smaller than a full stripe. (Zhe Zhang)
Yes. cellSize is relavant.
>...I find the above usecase very compelling, which is why I've been advocating
>for using the file header bits. I haven't seen much competition for the bits
>either, and we can also start conservatively when using bits (only as many as
>we need). (Andrew Wang)
Agree.
So, have we reached a consensus? Have other different thoughts, guys?
> Erasure coding: store EC schema and cell size in INodeFile and eliminate
> notion of EC zones
> -------------------------------------------------------------------------------------------
>
> Key: HDFS-8833
> URL: https://issues.apache.org/jira/browse/HDFS-8833
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: namenode
> Affects Versions: HDFS-7285
> Reporter: Zhe Zhang
> Assignee: Zhe Zhang
> Attachments: HDFS-8833-HDFS-7285-merge.00.patch,
> HDFS-8833-HDFS-7285-merge.01.patch, HDFS-8833-HDFS-7285.02.patch
>
>
> We have [discussed |
> https://issues.apache.org/jira/browse/HDFS-7285?focusedCommentId=14357754&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14357754]
> storing EC schema with files instead of EC zones and recently revisited the
> discussion under HDFS-8059.
> As a recap, the _zone_ concept has severe limitations including renaming and
> nested configuration. Those limitations are valid in encryption for security
> reasons and it doesn't make sense to carry them over in EC.
> This JIRA aims to store EC schema and cell size on {{INodeFile}} level. For
> simplicity, we should first implement it as an xattr and consider memory
> optimizations (such as moving it to file header) as a follow-on. We should
> also disable changing EC policy on a non-empty file / dir in the first phase.
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