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From aaron morton <aa...@thelastpickle.com>
Subject Re: Bootstrapping a new node to a running cluster
Date Fri, 16 Mar 2012 09:12:18 GMT
I think your original plan is sound. 

1. Up the RF to 4. 
2. Add the node with auto_bootstrap true
3. Once bootrapping has finished the new node has all the data it needs. 
4. Check for secondary index creation using describe in the CLI to see which are build. You
can also see progress using nodetool compactionstats

> I'm a bit puzzled though, I just tried to increase R to 3 in a cluster with N=2. It serves
reads and writes without issues CL.one. Is the described restriction is something that will
be implemented in the future?
I had a quick glance at the code. IIRC there was an explicit check if RF > N, but I cannot
find it any more. I'm guessing we now rely on a normal UnavailableFailure if there are not
enough UP nodes. 

Cheers

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

On 16/03/2012, at 8:56 PM, Mikael Wikblom wrote:

> ok, thank you both for the clarification. So the correct approach would be to bootstrap
the new node and run repair on each of the nodes in the cluster.
> 
> I'm a bit puzzled though, I just tried to increase R to 3 in a cluster with N=2. It serves
reads and writes without issues CL.one. Is the described restriction is something that will
be implemented in the future?
> 
> Thank you
> Regards
> 
> 
> 
> 
> On 03/16/2012 03:07 AM, aaron morton wrote:
>> 
>> The documentation is correct. 
>> I was mistakenly remembering discussions in the past about RF > #nodes. 
>> 
>> Cheers
>> 
>> -----------------
>> Aaron Morton
>> Freelance Developer
>> @aaronmorton
>> http://www.thelastpickle.com
>> 
>> On 16/03/2012, at 4:34 AM, Doğan Çeçen wrote:
>> 
>>>> I'm not sure why this is not allowed. As long as I do not use CL.all there
>>>> will be enough nodes available to satisfy the read / write (at least when
I
>>>> look at ReadCallback and the WriteResponseHandler). Or am I missing
>>>> something here?
>>> 
>>> According to http://www.datastax.com/docs/1.0/cluster_architecture/replication
>>> 
>>> "As a general rule, the replication factor should not exceed the
>>> number of nodes in the cluster. However, it is possible to increase
>>> replication factor, and then add the desired number of nodes
>>> afterwards. When replication factor exceeds the number of nodes,
>>> writes will be rejected, but reads will be served as long as the
>>> desired consistency level can be met."
>>> 
>>> -- 
>>> ()  ascii ribbon campaign - against html e-mail
>>> /\  www.asciiribbon.org   - against proprietary attachments
>> 
> 
> 
> -- 
> Mikael Wikblom
> Software Architect
> SiteVision AB
> 019-217058
> mikael.wikblom@sitevision.se
> http://www.sitevision.se


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