[jira] [Commented] (HDFS-3752) BOOTSTRAPSTANDBY for new Standby node will not work just after saveNameSpace at ANN in case of BKJM

["Rakesh R (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HDFS-3752?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13865367#comment-13865367 ] 

Rakesh R commented on HDFS-3752:
--------------------------------

Hi, As I understood from the discussion, when bootstrapping the standby it is not very much required to see the transactions present in the 'in_progress' node and skipping of 'in_progress' will not cause any inconsistencies.  Anyway StandbyToActive transition will always ensure, the edit delta transactions will be read from the shared edit dirs and able to reliably start as Active.

bq.we could add an easy workaround flag, like "bootstrapStandby -skipSharedEditsCheck", since the check here is just to help out the user and not actually necessary for correct operation.
I also agree in skipping the shared edits check during bootstrapstandby, in that case there is no special fix required for this JIRA. 
Presently, there is no test cases for bootstrap with BKJM shared edits and I've tried few. Could you please review the attached test case patch. If everyone agrees, push this in and and can close this JIRA once HDFS-4120 is in. Any thoughts?


> BOOTSTRAPSTANDBY for new Standby node will not work just after saveNameSpace at ANN in case of BKJM
> ---------------------------------------------------------------------------------------------------
>
>                 Key: HDFS-3752
>                 URL: https://issues.apache.org/jira/browse/HDFS-3752
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: ha
>    Affects Versions: 2.0.0-alpha
>            Reporter: Vinay
>         Attachments: HDFS-3752-testcase.patch
>
>
> 1. do {{saveNameSpace}} in ANN node by entering into safemode
> 2. in another new node, install standby NN and do BOOTSTRAPSTANDBY
> 3. Now StandBy NN will not able to copy the fsimage_txid from ANN
> This is because, SNN not able to find the next txid (txid+1) in shared storage.
> Just after {{saveNameSpace}} shared storage will have the new logsegment with only START_LOG_SEGEMENT edits op.
> and BookKeeper will not be able to read last entry from inprogress ledger.



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