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https://issues.apache.org/jira/browse/HDFS-7859?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14494933#comment-14494933
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Tsz Wo Nicholas Sze commented on HDFS-7859:
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I have the following questions:
- How to add a schema? Using a command?
- Then, is it possible to delete a schema? It seems that we have to support
deletion since a schema may be created by mistake or there could be typos when
creating a schema.
- If deletion is supported, what to do with the existing files with that schema?
- Do we support renaming schema?
- Does a EC schema have a schema ID?
I think we need a design for EC schema to answer all these questions and
specify what operations are supported.
BTW, we only support one schema (6,3)-Reed-Solomon in the first phase
HDFS-7285. I think we should focus on finishing a complete, working basic EC
feature and get HDFS-7285 merged to trunk. How about moving this JIRA and
related JIRAs to HDFS-8031 and defer the work? Sorry for commenting on this
late and thanks for all the good works.
> Erasure Coding: Persist EC schemas in NameNode
> ----------------------------------------------
>
> Key: HDFS-7859
> URL: https://issues.apache.org/jira/browse/HDFS-7859
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Reporter: Kai Zheng
> Assignee: Xinwei Qin
> Attachments: HDFS-7859.001.patch
>
>
> In meetup discussion with [~zhz] and [~jingzhao], it's suggested that we
> persist EC schemas in NameNode centrally and reliably, so that EC zones can
> reference them by name efficiently.
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