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From lohit <lohit...@yahoo.com>
Subject Re: 64 bit namenode and secondary namenode & 32 bit datanode
Date Wed, 26 Nov 2008 00:39:04 GMT
Well, if I think about,  image corruption might not happen, since each checkpoint initiation
would have unique number.

I was just wondering what would happen in this case
Consider this scenario.
Time 1 <-- SN1 asks NN image and edits to merge
Time 2 <-- SN2 asks NN image and edits to merge
Time 2 <-- SN2 returns new image
Time 3 <-- SN1 returns new image. 
I am not sure what happens here, but its best to test it out before setting up something like
this.

And if you have multiple entries in NN file, then one SNN checkpoint would update all NN entries,
so redundant SNN isnt buying you much.

Thanks,
Lohit



----- Original Message ----
From: Sagar Naik <snaik@attributor.com>
To: core-user@hadoop.apache.org
Sent: Tuesday, November 25, 2008 4:32:26 PM
Subject: Re: 64 bit namenode and secondary namenode & 32 bit datanode



lohit wrote:
> I might be wrong, but my assumption is running SN either in 64/32 shouldn't matter. 
> But I am curious how two instances of Secondary namenode is setup, will both of them
talk to same NN and running in parallel? 
> what are the advantages here.
>  
I just have multiple entries master file. I am not aware of image 
corruption (did not take look into it). I did for SNN redundancy
Pl correct me if I am wrong
Thanks
Sagar
> Wondering if there are chances of image corruption.
>
> Thanks,
> lohit
>
> ----- Original Message ----
> From: Sagar Naik <snaik@attributor.com>
> To: core-user@hadoop.apache.org
> Sent: Tuesday, November 25, 2008 3:58:53 PM
> Subject: 64 bit namenode and secondary namenode & 32 bit datanode
>
> I am trying to migrate from 32 bit jvm and 64 bit for namenode only.
> *setup*
> NN - 64 bit
> Secondary namenode (instance 1) - 64 bit
> Secondary namenode (instance 2)  - 32 bit
> datanode                                        - 32 bit
>
> From the mailing list I deduced that NN-64 bit and Datanode -32 bit combo works
> But, I am not sure if S-NN-(instance 1--- 64 bit ) and S-NN (instance 2 -- 32 bit) will
work with this setup.
>
> Also, do shud I be aware of any other issues for migrating over to 64 bit namenode
>
> Thanks in advance for all the suggestions
>
>
> -Sagar
>
>  

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