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From aaron morton <aa...@thelastpickle.com>
Subject Re: tokens and RF for multiple phases of deployment
Date Fri, 01 Jun 2012 01:52:40 GMT
> The ring (2 in DC1, 1 in DC2) looks OK, but the load on the new node in DC2 is almost
0%.
yeah, thats the way it will look. 

> But all the other rows are not in the new node. Do I need to copy the data files from
a node in DC1 to the new node?

How did you add the node ? (see http://www.datastax.com/docs/1.0/operations/cluster_management#adding-nodes-to-a-cluster)

if in doubt run nodetool repair on the new node. 

Cheers


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

On 1/06/2012, at 3:46 AM, Chong Zhang wrote:

> Thanks Aaron.
> 
> I might use LOCAL_QUORUM to avoid the waiting on the ack from DC2.
> 
> Another question, after I setup a new node with token +1 in a new DC,  and updated a
CF with RF {DC1:2, DC2:1}. When i update a column on one node in DC1, it's also updated in
the new node in DC2. But all the other rows are not in the new node. Do I need to copy the
data files from a node in DC1 to the new node?
> 
> The ring (2 in DC1, 1 in DC2) looks OK, but the load on the new node in DC2 is almost
0%.
> 
> Address         DC          Rack        Status State   Load            Owns    Token
                                      
>                                                                                85070591730234615865843651857942052864
     
> 10.10.10.1    DC1         RAC1        Up     Normal  313.99 MB       50.00%  0      
                                    
> 10.10.10.3    DC2         RAC1        Up     Normal  7.07 MB           0.00%   1    
                                      
> 10.10.10.2    DC1         RAC1        Up     Normal  288.91 MB       50.00%  85070591730234615865843651857942052864
     
> 
> Thanks,
> Chong
> 
> On Thu, May 31, 2012 at 5:48 AM, aaron morton <aaron@thelastpickle.com> wrote:
> 
>> Could you provide some guide on how to assign the tokens in this growing deployment
phases? 
> 
> background http://www.datastax.com/docs/1.0/install/cluster_init#calculating-tokens-for-a-multi-data-center-cluster
> 
> Start with tokens for a 4 node cluster. Add the next 4 between between each of the ranges.
Add 8 in the new DC to have the same tokens as the first DC +1
> 
>> Also if we use the same RF (3) in both DC, and use EACH_QUORUM for write and LOCAL_QUORUM
for read, can the read also reach to the 2nd cluster?
> No. It will fail if there are not enough nodes available in the first DC. 
> 
>> We'd like to keep both write and read on the same cluster.
> Writes go to all replicas. Using EACH_QUORUM means the client in the first DC will be
waiting for the quorum from the second DC to ack the write. 
> 
> 
> Cheers
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 31/05/2012, at 3:20 AM, Chong Zhang wrote:
> 
>> Hi all,
>> 
>> We are planning to deploy a small cluster with 4 nodes in one DC first, and will
expend that to 8 nodes, then add another DC with 8 nodes for fail over (not active-active),
so all the traffic will go to the 1st cluster, and switch to 2nd cluster if the whole 1st
cluster is down or on maintenance. 
>> 
>> Could you provide some guide on how to assign the tokens in this growing deployment
phases? I looked at some docs but not very clear on how to assign tokens on the fail-over
case.
>> Also if we use the same RF (3) in both DC, and use EACH_QUORUM for write and LOCAL_QUORUM
for read, can the read also reach to the 2nd cluster? We'd like to keep both write and read
on the same cluster.
>> 
>> Thanks in advance,
>> Chong
> 
> 


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