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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Network Topology Strategy error
Date Thu, 03 Mar 2011 22:10:52 GMT
Sounds like your nodes are not evenly spaced around the ring in each dc.

On Thu, Mar 3, 2011 at 4:09 PM, A J <s5alye@gmail.com> wrote:
> Thanks.
> It worked when I changed as you suggested to: create keyspace ks1 with
> strategy_options = [{DC1:1, DC2:1}] and
> placement_strategy='org.apache.cassandra.locator.NetworkTopologyStrategy';
>
> Something that I am observing:
> The replicas are always put in the first node on the other DC. (So if
> there are 2 nodes in each DC, replica of both nodes goes to the first
> node in the other DC. And vice-versa)
> This would make the first node in each DC a hotspot. Am I doing
> something wrong ? If not, any way to avoid this ?
>
>
>
> On Thu, Mar 3, 2011 at 3:41 PM, Jonathan Ellis <jbellis@gmail.com> wrote:
>> you need to specify per-DC replicas w/ NTS in strategy_options,
>> instead of using replication_factor
>>
>> On Thu, Mar 3, 2011 at 1:52 PM, A J <s5alye@gmail.com> wrote:
>>> using latest cassandra (0.7.2). I want to try out Network Topology Strategy.
>>>
>>> Following is related setting in cassandra.yaml
>>> endpoint_snitch: org.apache.cassandra.locator.PropertyFileSnitch
>>>
>>> I have four nodes. Set them accordingly in ./conf/cassandra-topology.properties:
>>> 10.252.219.224=DC2:RAC1
>>> 10.252.10.64=DC2:RAC1
>>> 10.252.11.32=DC1:RAC1
>>> 10.220.103.98=DC1:RAC1
>>>
>>>
>>> I create a ks as:
>>> create keyspace ks1 with replication_factor=1 and
>>> placement_strategy='org.apache.cassandra.locator.NetworkTopologyStrategy';
>>>
>>> When I try to insert, get the following error:
>>> set cf1['A']['c1']='xyz';
>>> ERROR 19:21:58,081 Internal error processing insert
>>> java.lang.AssertionError: invalid response count 1 for replication factor 0
>>>
>>>
>>> Please suggest what could be going on ? cassandra-topology.properties
>>> has two DCs. Why am I still getting the error ?
>>>
>>> Thanks for any suggestions.
>>>
>>
>>
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of DataStax, the source for professional Cassandra support
>> http://www.datastax.com
>>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com

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