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https://issues.apache.org/jira/browse/ZOOKEEPER-2574?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15486135#comment-15486135
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Hadoop QA commented on ZOOKEEPER-2574:
--------------------------------------

+1 overall.  Here are the results of testing the latest attachment 
  
http://issues.apache.org/jira/secure/attachment/12827931/ZOOKEEPER-2574.3.patch
  against trunk revision b2a484cfe743116d2531fe5d1e1d78b3960c511e.

    +1 @author.  The patch does not contain any @author tags.

    +1 tests included.  The patch appears to include 3 new or modified tests.

    +1 javadoc.  The javadoc tool did not generate any warning messages.

    +1 javac.  The applied patch does not increase the total number of javac 
compiler warnings.

    +1 findbugs.  The patch does not introduce any new Findbugs (version 2.0.3) 
warnings.

    +1 release audit.  The applied patch does not increase the total number of 
release audit warnings.

    +1 core tests.  The patch passed core unit tests.

    +1 contrib tests.  The patch passed contrib unit tests.

Test results: 
https://builds.apache.org/job/PreCommit-ZOOKEEPER-Build/3422//testReport/
Findbugs warnings: 
https://builds.apache.org/job/PreCommit-ZOOKEEPER-Build/3422//artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html
Console output: 
https://builds.apache.org/job/PreCommit-ZOOKEEPER-Build/3422//console

This message is automatically generated.

> PurgeTxnLog can inadvertently delete required txn log files
> -----------------------------------------------------------
>
>                 Key: ZOOKEEPER-2574
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2574
>             Project: ZooKeeper
>          Issue Type: Bug
>          Components: server
>    Affects Versions: 3.4.7, 3.4.8, 3.5.0, 3.5.1, 3.5.2
>         Environment: Zookeeper 3.4.8, standalone, and 3-server quorum
>            Reporter: Abhishek Rai
>            Assignee: Abhishek Rai
>            Priority: Blocker
>             Fix For: 3.4.10, 3.5.3
>
>         Attachments: ZOOKEEPER-2574.2.patch, ZOOKEEPER-2574.3.patch, 
> ZOOKEEPER-2574.patch
>
>
> As part of the fix for ZOOKEEPER-1797, the call to 
> FileTxnSnapLog.getSnapshotLogs() was removed from PurgeTxnLog.java.  As a 
> result, some old-looking but required txn log files can be deleted, resulting 
> in data corruption or loss.
> For example, consider the following:
> 1. Configuration:
> autopurge.snapRetainCount=3
> 2. Following files exist:
> log.100 spans transactions from zxid=100 till zxid=140 (inclusive)
> snapshot.110 - snapshot as of zxid=110
> snapshot.120 - snapshot as of zxid=120
> snapshot.130 - snapshot as of zxid=130
> Above scenario is possible when snapshotting has happened multiple times but 
> without accompanying log rollover, which is possible if the server was 
> running as a learner.
> 3. PurgeTxnLog retains all snapshots but deletes log.100 because its zxid is 
> older than the zxid of the oldest snapshot (110).  This results in loss of 
> transactions in the range 131-140.
> Before the fix for ZOOKEEPER-1797, this was avoided by the call to 
> FileTxnSnapLog.getSnapshotLogs() which finds and retains the newest txn log 
> file with starting zxid < oldest retained snapshot's highest zxid.



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