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From "Desimpel, Ignace" <Ignace.Desim...@nuance.com>
Subject RE: RE Restore snapshot
Date Thu, 02 Aug 2012 10:20:40 GMT
Great! I will use the hardlinks to 'restore' the data files on each node (super fast)!
I have some related questions :

1) I assume that I have to call the loadNewSSTables() on each node?

2) To be on the save side, I guess I better drop the existing keyspace and then recreate using
the definition at the time of the snapshot. But is it allowed the copy the 'old' data files
after that with respect to new internal ids versus ids maintained (if any) in the data files?

3) A quick look at the code (took 1.0.5), is it possible that the Table.open is also calling
the initCaches on the CFs, but the loadNewSSTables is not?

4) As a solution to 3) : I'm working with embedded Cassandra servers, so I think it would
be possible for me to do the following
  *Drop KS x if present
  *Create KS x from old definition
  *On each node :
  *** Table.clear(x)
  *** Delete any remaining files in the directory x
  *** Restore data files from snapshot for KS x
  *** Table.open(x);

-----Original Message-----
From: Sylvain Lebresne [mailto:sylvain@datastax.com] 
Sent: donderdag 2 augustus 2012 11:46
To: user@cassandra.apache.org
Subject: Re: RE Restore snapshot

Actually that's wrong, it is perfectly possible to restore a snapshot on a live cassandra
cluster.
There is even basically 2 solutions:
1) use the sstableloader (http://www.datastax.com/dev/blog/bulk-loading)
2) copy the snapshot sstable in the right place and call the JMX method loadNewSSTables()
(in the column family MBean, which mean you need to do that per-CF).

--
Sylvain

On Thu, Aug 2, 2012 at 9:16 AM, Romain HARDOUIN <romain.hardouin@urssaf.fr> wrote:
>
> No it's not possible
>
> "Desimpel, Ignace" <Ignace.Desimpel@nuance.com> a écrit sur 01/08/2012
> 14:58:49 :
>
>> Hi,
>>
>> Is it possible to restore a snapshot of a keyspace on a live 
>> cassandra cluster (I mean without restarting)?
>>

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