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From aaron morton <aa...@thelastpickle.com>
Subject Re: Data not replicating to all datacenters
Date Mon, 03 Dec 2012 20:18:47 GMT
>>> When reading, sometimes the data is there,
>>> sometimes it is not, which we think is a replication issue, even
>>> though we have left it plenty of time after the writes.
Can you provide some more information on this ? 
Are you talking about writes to one DC and reads from another ? 

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 4/12/2012, at 6:45 AM, Шамим <srecon@yandex.ru> wrote:

> Yes, it's should be. dc1:3 means u have 3 copy of every piece of row, with local quorum
you always get a good consistency from 3 nodes. 
> First you have to calculate token for data center dc1 and add offset 100 to token for
the second data center which will resolve your problem. After creating the keyspace you can
run the nodetool command with ring KEYSPACE NAME which should show u the load for every node
as 33%
> Hope it will help u
> Shamim
>> Hi Shamim
>> 
>> I have read a bit about the Tokens. I understand how that could effect
>> the data distribution at first, but I don't understand if we have
>> specified Options: [dc1:3, dc2:3], surely after a while all the data
>> will be on every server?
>> 
>> Thanks,
>> 
>> Owen
>> 
>> On 3 December 2012 14:06, Шамим <srecon@yandex.ru> wrote:
>> 
>>> Hello Owen,
>>> Seems you did not configure token for all nodes correctly. See the section Calculating
Tokens for multiple data centers here http://www.datastax.com/docs/0.8/install/cluster_init
>>> 
>>> Best regards
>>> Shamim
>>> ---
>>> On Mon, Dec 3, 2012 at 4:42 PM, Owen Davies <cassandra@obduk.com> wrote:
>>> 
>>> We have a 2 data center test cassandra setup running, and are writing
>>> to it using LOCAL_QUORUM. When reading, sometimes the data is there,
>>> sometimes it is not, which we think is a replication issue, even
>>> though we have left it plenty of time after the writes.
>>> 
>>> We have the following setup:
>>> 
>>> cassandra -v: 1.1.6
>>> 
>>> cassandra.yaml
>>> -----------------------
>>> 
>>> cluster_name: something
>>> 
>>> endpoint_snitch: PropertyFileSnitch
>>> 
>>> cassandra-topology.properties
>>> --------------------------------------------
>>> 192.168.1.1=dc1:rack1
>>> 192.168.1.2=dc1:rack1
>>> 192.168.1.3=dc1:rack1
>>> 
>>> 192.168.2.1=dc2:rack1
>>> 192.168.2.2=dc2:rack1
>>> 192.168.2.3=dc3:rack1
>>> 
>>> default=nodc:norack
>>> 
>>> cassandra-cli
>>> --------------------
>>> Keyspace: example:
>>> Replication Strategy: org.apache.cassandra.locator.NetworkTopologyStrategy
>>> Durable Writes: true
>>> Options: [dc1:3, dc2:3]
>>> 
>>> nodetool ring
>>> -------------------
>>> 
>>> Address DC Rack Status State Load
>>> Effective-Ownership Token
>>> 
>>> 159447687142037741049740936276011715300
>>> 192.168.1.2 dc1 rack1 Up Normal 111.17 GB
>>> 100.00% 67165620003619490909052924699950283577
>>> 192.168.1.1 dc1 rack1 Up Normal 204.57 GB
>>> 100.00% 71045951808949151217931264995073558408
>>> 192.168.2.1 dc2 rack1 Up Normal 209.92 GB
>>> 100.00% 107165019770579893816561717940612111506
>>> 192.168.1.3 dc1 rack1 Up Normal 209.92 GB
>>> 100.00% 114165363957966360026729000065495595953
>>> 192.168.2.3 dc2 rack1 Up Normal 198.22 GB
>>> 100.00% 147717787092318068320268200174271353451
>>> 192.168.2.2 dc2 rack1 Up Normal 179.31 GB
>>> 100.00% 159447687142037741049740936276011715300
>>> 
>>> Does anyone have any ideas why every server does not have the same
>>> amount of data on?
>>> 
>>> Thanks,
>>> 
>>> Owen
> 
> 
> -- 


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