Migration from 0.7 to 1.0

["cbertu81@libero.it" <cb...@libero.it>]

Hi,
I'm going to migrate from Cassandra 0.7 to 1.0 in production and I'd like to 
know the best way to do it ...

"Upgrading from version 0.7.1+ or 0.8.2+ can be done with a rolling restart, 
one node at a time.  (0.8.0 or 0.8.1 are NOT network-compatible with 1.0: 
upgrade to the most recent 0.8 release first.) You do not need to bring down 
the whole cluster at once.  - After upgrading, run nodetool scrub against each 
node before running repair, moving nodes, or adding new ones."

So what I'd do is for each node to ...

1 - run nodetool drain
2 - stop cassandra process
3 - start the new cassandra 1.0
4 - run nodetool scrub on the node

Is it right? Do i miss something (I will backup everything before the 
upgrade)? Should I worry for some kind of particular/known problems? As far as 
maintenance is concerned, is enough to run a repair every x? (x < 
GCGraceSeconds)

Best regards,
Carlo

Re: Migration from 0.7 to 1.0

[aaron morton <aa...@thelastpickle.com>]

Sounds good. 

You can take some extra steps when doing a rolling restart see http://blog.milford.io/2011/11/rolling-upgrades-for-cassandra/

Also make sure repair *does not* run until all the nodes have been upgraded. 

> Do i miss something (I will backup everything before the 
> upgrade)? 
I'm paranoid, so I would  upgrade 1 node and let it soak in for a few hours. Nothing like upgrading an entire cluster and then discovering a problem. 

> As far as 
> maintenance is concerned, is enough to run a repair every x? (x < 
> GCGraceSeconds)
once for each node with in that time frame http://wiki.apache.org/cassandra/Operations#Frequency_of_nodetool_repair


Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 5/01/2012, at 2:47 AM, cbertu81@libero.it wrote:

> Hi,
> I'm going to migrate from Cassandra 0.7 to 1.0 in production and I'd like to 
> know the best way to do it ...
> 
> "Upgrading from version 0.7.1+ or 0.8.2+ can be done with a rolling restart, 
> one node at a time.  (0.8.0 or 0.8.1 are NOT network-compatible with 1.0: 
> upgrade to the most recent 0.8 release first.) You do not need to bring down 
> the whole cluster at once.  - After upgrading, run nodetool scrub against each 
> node before running repair, moving nodes, or adding new ones."
> 
> So what I'd do is for each node to ...
> 
> 1 - run nodetool drain
> 2 - stop cassandra process
> 3 - start the new cassandra 1.0
> 4 - run nodetool scrub on the node
> 
> Is it right? Do i miss something (I will backup everything before the 
> upgrade)? Should I worry for some kind of particular/known problems? As far as 
> maintenance is concerned, is enough to run a repair every x? (x < 
> GCGraceSeconds)
> 
> Best regards,
> Carlo