Hi Sreehari,
Which versions are you using for this test?
In step 1 below, how does the upgrade fail? Can you provide specific steps
to reproduce?
Smells like a bug to me, if I understand the scenario correctly.
-Todd
On Mon, May 30, 2011 at 5:29 AM, Sreehari G <sreehar...@huawei.com> wrote:
> Hi all ,
>
> What is the expectation in the following scenario :
>
> Namenode has 3 name dirs configured ..
> 1) Namenode upgrade starts - Upgrade fails after 1st directory is upgraded
> (2nd and 3rd dir is left unchanged ..)
> 2) Namenode starts
> 3) Namenode shutdown and rollbacked
>
> Are the new changes done meant to be visible ? With current implementation
> , after a rollback new changes are visible .. Is this expected ??
>
> As per my observation , since Namenode is saving the latest image dir(the
> upgraded 1st dir since checkpointtime is incremented during upgrade for this
> dir) will be loaded and saved to all dirs during loadfsimage ..
>
> But if a ROLLBACK is done , the 1st dir will be rolled back (the older copy
> becomes current and its checkpointtime is now LESS than other dirs ..) and
> others left behind since they dont contain previous .. Now during
> loadfsimage , the 2nd dir will be selected since it has the highest
> checkpoint time and saved to all dirs (including 1st ) .. Now due to this ,
> the new changes b/w UPGRADE and ROLLBACK DELTA present in 2nd dir gets
> reflected even after ROLLBACK ..
>
> Is this expected ? I ask this since :
>
> 1) this is not the case with a SUCCESSFULL Upgrade/Rollback (New changesare
> lost
> after rollback).. &
> 2) In Hadoop-702 (DFS Upgrade Proposal) , FSStateTransition7.htm says {
> r0. if previous directory does not exist then fail rollback } , but it
> continues in the current implementation ..
>
>
>
> Regards ,
>
> Sreehari
>
> HUAWEI TECHNOLOGIES CO.,LTD. [image: huawei_logo]
>
>
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> Bangalore
> www.huawei.com
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Todd Lipcon
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