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https://issues.apache.org/jira/browse/HDFS-7839?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14344362#comment-14344362
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Kai Zheng commented on HDFS-7839:
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Hi [~zhz],
bq.Where do you suggest we add those? In the XAttr?
I thought it would be good to get EC zone associate an EC schema even at this
stage, so that any necessary parameters like that can be determined thereafter
for the zone. Is it possible to get HADOOP-11643 in first for this ?
bq.I planned to leave the schema parameter to HDFS-7866 but we can certainly
add a place holder (a short type) here
How about String type instead for the schema parameter ? In future, if we're
clear integer identifier is better than unique predefined name, we can adjust
it later.
bq.FSDirectory does have a isStrippedFile method. Per Andrew's suggestion, I'm
consolidating all actual XAttr operations in the manager class.
Yes, I saw it. What I meant is we move the logic codes there, because it's more
FS related and nature. In my view, the manager would focus on EC zone
manageability facilities. In the patch you can see that
{{FSDirectory.isStrippedFile}} is referenced much more.
bq.{{ErasureCodingManager}} was named following the convention of
{{EncryptionZoneManager}}.
Yes I know. I thought {{ECZoneManager}} would follow a bit nearer
{{EncryptionZoneManager}}, and also be good with {{ECManager}}, {{ECWorker}}
and {{ECSchema}} etc.
bq.Maybe we should allow it here as well ?
It's hard to decide, but for now for simple, I thought no nesting even at root
would be ok for us. We can keep such questions and then revisit them at some
time later. Just leave a comment in the codes ?
> Erasure coding: implement facilities in NameNode to create and manage EC zones
> ------------------------------------------------------------------------------
>
> Key: HDFS-7839
> URL: https://issues.apache.org/jira/browse/HDFS-7839
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Reporter: Zhe Zhang
> Assignee: Zhe Zhang
> Attachments: HDFS-7839-000.patch, HDFS-7839-001.patch
>
>
> As a quick first step to facilitate initial development and testing,
> HDFS-7347 added EC configuration in file header as one storage policy. We
> have discussed and [concluded
> |https://issues.apache.org/jira/browse/HDFS-7285?focusedCommentId=14296210&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14296210]
> that EC configurations should be part of XAttr. This JIRA aims to add the
> basic EC XAttr structure. HDFS-7337 will add configurable and pluggable
> schema info.
> To summarize, this will focus on providing relevant facilities in NameNode
> side to create and manage EC zones. EC zone will associate, reference and
> store the needed schema name as XAttr. EC schema information will be
> persisted in NameNode elsewhere centrally.
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