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https://issues.apache.org/jira/browse/YARN-1307?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13804752#comment-13804752
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Tsuyoshi OZAWA commented on YARN-1307:
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Not quite sure what you mean by encoding. There is nothing to encode.
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I apologize that I confuse you with the term "encoding". Currently, sequence
numbers of RMDelegationToken_* and RMDelegationKey_* are stored with raw
sequence numbers. Now we use sequential number when storing RMDelegationToken
and RMDelegationKey direclty like RMDelegationToken_1, RMDelegationToken_2,
RMDelegationToken_3(This number is related to sequential number) and
RMDelegationKey_1, RMDelegationKey_2, RMDelegationKey_3(This number is not
related to znode's sequential number). If we should avoid encoding sequence
numbers in the znode names since listing of paths is less protected in znode
and the info may be visible to those who dont have other access, we can need to
use SHA1 or some hash functions for znodes based on sequence number and secret
password that users can specify in yarn-site.xml. I meant this was encoding. Is
this wrong?
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We can always just write the znode since we already have all the data.
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I see. RM has the tokens, so RM no need to read again. We can access it with
sequcential number. Some empty entries are generated when remove*() methods are
called, but we can just ignore them.
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We can do the batching optimization after this.
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OK. I agree with this. I'll create new JIRA to do batching optimization.
> Rethink znode structure for RM HA
> ---------------------------------
>
> Key: YARN-1307
> URL: https://issues.apache.org/jira/browse/YARN-1307
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: resourcemanager
> Reporter: Tsuyoshi OZAWA
> Assignee: Tsuyoshi OZAWA
> Attachments: YARN-1307.1.patch, YARN-1307.2.patch
>
>
> Rethink for znode structure for RM HA is proposed in some JIRAs(YARN-659,
> YARN-1222). The motivation of this JIRA is quoted from Bikas' comment in
> YARN-1222:
> {quote}
> We should move to creating a node hierarchy for apps such that all znodes for
> an app are stored under an app znode instead of the app root znode. This will
> help in removeApplication and also in scaling better on ZK. The earlier code
> was written this way to ensure create/delete happens under a root znode for
> fencing. But given that we have moved to multi-operations globally, this isnt
> required anymore.
> {quote}
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