[jira] [Commented] (HADOOP-9459) ActiveStandbyElector can join election even before Service HEALTHY, and results in null data at ActiveBreadCrumb

["Hadoop QA (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HADOOP-9459?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13624044#comment-13624044 ] 

Hadoop QA commented on HADOOP-9459:
-----------------------------------

{color:green}+1 overall{color}.  Here are the results of testing the latest attachment 
  http://issues.apache.org/jira/secure/attachment/12567834/HDFS-4463.patch
  against trunk revision .

    {color:green}+1 @author{color}.  The patch does not contain any @author tags.

    {color:green}+1 tests included{color}.  The patch appears to include 1 new or modified test files.

    {color:green}+1 javac{color}.  The applied patch does not increase the total number of javac compiler warnings.

    {color:green}+1 javadoc{color}.  The javadoc tool did not generate any warning messages.

    {color:green}+1 eclipse:eclipse{color}.  The patch built with eclipse:eclipse.

    {color:green}+1 findbugs{color}.  The patch does not introduce any new Findbugs (version 1.3.9) warnings.

    {color:green}+1 release audit{color}.  The applied patch does not increase the total number of release audit warnings.

    {color:green}+1 core tests{color}.  The patch passed unit tests in hadoop-common-project/hadoop-common.

    {color:green}+1 contrib tests{color}.  The patch passed contrib unit tests.

Test results: https://builds.apache.org/job/PreCommit-HADOOP-Build/2418//testReport/
Console output: https://builds.apache.org/job/PreCommit-HADOOP-Build/2418//console

This message is automatically generated.
                
> ActiveStandbyElector can join election even before Service HEALTHY, and results in null data at ActiveBreadCrumb
> ----------------------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-9459
>                 URL: https://issues.apache.org/jira/browse/HADOOP-9459
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: ha
>    Affects Versions: 2.0.2-alpha
>            Reporter: Vinay
>            Assignee: Vinay
>            Priority: Critical
>         Attachments: HDFS-4463.patch, hdfs-4463.txt
>
>
> ActiveStandbyElector can store null at ActiveBreadCrumb in the below race condition. At further all failovers will fail resulting NPE.
> 1. ZKFC restarted.
> 2. due to machine busy, first zk connection is expired even before the health monitoring returned the status.
> 3. On re-establishment transitionToActive will be called, at this time appData will be null,
> 4. So now ActiveBreadCrumb will have null.
> 5. After this any failovers will fail throwing 
> {noformat}java.lang.NullPointerException
> 	at org.apache.hadoop.util.StringUtils.byteToHexString(StringUtils.java:171)
> 	at org.apache.hadoop.ha.ActiveStandbyElector.fenceOldActive(ActiveStandbyElector.java:892)
> 	at org.apache.hadoop.ha.ActiveStandbyElector.becomeActive(ActiveStandbyElector.java:797)
> 	at org.apache.hadoop.ha.ActiveStandbyElector.processResult(ActiveStandbyElector.java:475)
> 	at org.apache.zookeeper.ClientCnxn$EventThread.processEvent(ClientCnxn.java:545)
> 	at org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:497){noformat}
> Should not join the election before service is HEALTHY

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira