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https://issues.apache.org/jira/browse/KYLIN-3562?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16819672#comment-16819672
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zhao jintao commented on KYLIN-3562:
------------------------------------

Hi, [~Aron.tao],[~Shaofengshi]:

I want to know why save user information  to HBase when user authentication?

user authenticate is in kylin process,it is not necessary to save the user to 
HBase.


In kylin-cluster mode, if same user login kylin in multiple nodes at the same 
time, multiple nodes simultaneously save user information to HBase, This is 
easy to cause “Overwriting conflict” error.

In my Kylin System, I use kylin jdbc  to access kylin-cluster and query sql. 
But sometimes kylin mistakes and throw 500 error code exception. I removed the 
mechanism of saving to HBase after login kylin, Then it works fine.

> TS conflict when kylin update metadata in HBase
> -----------------------------------------------
>
>                 Key: KYLIN-3562
>                 URL: https://issues.apache.org/jira/browse/KYLIN-3562
>             Project: Kylin
>          Issue Type: Bug
>    Affects Versions: v2.4.0
>            Reporter: Lingang Deng
>            Assignee: Jiatao Tao
>            Priority: Major
>             Fix For: v2.4.2, v2.5.1
>
>         Attachments: image-2018-09-17-16-40-56-212.png, 
> image-2018-09-25-15-03-51-009.png, image-2018-09-25-16-43-50-277.png
>
>
> Error log was as follows,
> {code:java}
> org.apache.kylin.common.persistence.WriteConflictException: Overwriting 
> conflict /user/admin, expect old TS 1536928877043, but it is 1536928907207
>          at 
> org.apache.kylin.storage.hbase.HBaseResourceStore.checkAndPutResourceImpl(HBaseResourceStore.java:325)
>          at 
> org.apache.kylin.common.persistence.ResourceStore.checkAndPutResourceCheckpoint(ResourceStore.java:318)
>          at 
> org.apache.kylin.common.persistence.ResourceStore.putResource(ResourceStore.java:303)
>          at 
> org.apache.kylin.common.persistence.ResourceStore.putResource(ResourceStore.java:282)
>          at 
> org.apache.kylin.metadata.cachesync.CachedCrudAssist.save(CachedCrudAssist.java:192){code}
>  
> what disturbs me the most was that the error was happened several hours,  
> then my all build job and query job failed.



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