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https://issues.apache.org/jira/browse/ZOOKEEPER-3144?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16615483#comment-16615483
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Hudson commented on ZOOKEEPER-3144:
-----------------------------------

SUCCESS: Integrated in Jenkins build ZooKeeper-trunk #191 (See 
[https://builds.apache.org/job/ZooKeeper-trunk/191/])
ZOOKEEPER-3144: Fix potential ephemeral nodes inconsistent due to global (hanm: 
rev b58791016424e662c816e2253de96f3771f5d301)
* (edit) 
src/java/test/org/apache/zookeeper/server/quorum/FuzzySnapshotRelatedTest.java
* (edit) src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java


> Potential ephemeral nodes inconsistent due to global session inconsistent 
> with fuzzy snapshot
> ---------------------------------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-3144
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3144
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: server
>    Affects Versions: 3.5.4, 3.6.0, 3.4.13
>            Reporter: Fangmin Lv
>            Assignee: Fangmin Lv
>            Priority: Critical
>              Labels: pull-request-available
>             Fix For: 3.6.0
>
>          Time Spent: 0.5h
>  Remaining Estimate: 0h
>
> Found this issue recently when checking another prod issue, the problem is 
> that the current code will update lastProcessedZxid before it's actually 
> making change for the global sessions in the DataTree.
>  
> In case there is a snapshot taking in progress, and there is a small time 
> stall between set lastProcessedZxid and update the session in DataTree due to 
> reasons like thread context switch or GC, etc, then it's possible the 
> lastProcessedZxid is actually set to the future which doesn't include the 
> global session change (add or remove).
>  
> When reload this snapshot and it's txns, it will replay txns from 
> lastProcessedZxid + 1, so it won't create the global session anymore, which 
> could cause data inconsistent.
>  
> When global sessions are inconsistent, it might have ephemeral inconsistent 
> as well, since the leader will delete all the ephemerals locally if there is 
> no global sessions associated with it, and if someone have snapshot sync with 
> it then that server will not have that ephemeral as well, but others will. It 
> will also have global session renew issue for that problematic session.
>  
> The same issue exist for the closeSession txn, we need to move these global 
> session update logic before processTxn, so the lastProcessedZxid will not 
> miss the global session here.
>  
>  



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