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Hadoop, mail # user - Re: Recovering the namenode from failure


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Re: Recovering the namenode from failure
Michael Segel 2013-05-21, 16:33
I think what he's missing is to change the configurations to point to the new name node.

It sounds like the new NN has a different IP address from the old NN so the DNs don't know who to report to...

On May 21, 2013, at 11:23 AM, Todd Lipcon <[EMAIL PROTECTED]> wrote:

> Hi David,
>
> You shouldn't need to do anything to get your DNs to report in -- as best they can tell, it's the same NN. Do you see any error messages in the DN logs?
>
> -Todd
>
> On Tue, May 21, 2013 at 12:30 AM, David Parks <[EMAIL PROTECTED]> wrote:
> I’m on CDH4, and trying to recover both the namenode and cloudera manager VMs from HDFS after losing the namenode.
>
>  
>
> All of our backup VMs are on HDFS, so for the moment I just want to hack something together, copy the backup VMs off HDFS and get on with properly reconfiguring via CDH Manger.
>
>  
>
> So I’ve installed a plain ‘ol namenode on one of my cluster nodes and started it with –importCheckpoint (with the data from the secondary NN), this seems to have worked, I have a namenode web UI up which expects to find 32178 blocks.
>
>  
>
> But my plain namenode (on the same hostname and IP as the old namenode) says that there are no datanodes in the cluster.
>
>  
>
> What do I need in order to configure the datanodes to report their blocks into this new namenode (same IP & hostname)?
>
>  
>
> Thanks,
>
> David
>
>  
>
>
>
>
> --
> Todd Lipcon
> Software Engineer, Cloudera

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David Parks 2013-05-21, 07:30