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From Anthony Ikeda <anthony.ikeda....@gmail.com>
Subject Re: Configuring the keyspace correctly - NTS
Date Wed, 14 Sep 2011 22:46:32 GMT
Great that makes perfect sense - I apologise for not getting this right it
seems I'm doing someone elses job here.

Anthony


On Wed, Sep 14, 2011 at 3:15 PM, aaron morton <aaron@thelastpickle.com>wrote:

> The strategy_options for NTS accept the data centre name and the rf,
> [{<dc_name> : <dc_rf>}]
>
> Where the DC name comes from the snitch, so…
>
> SimpleSnitch (gotta love this guy, in there day in day out putting in the
> hard yards) puts all the nodes in "datacenter1" which is why thats in the
> defaults.
>
> RackInferringSnitch (or the "Hollywood Snitch" as I call it) puts the them
> in a DC named after the second octet of the IP. So 130 in your  case.
>
> PropertyFileSnitch does whats in the cassandra-topology.properties file.
> EC2Snitch uses the EC2 Region. Brisk snitch does it's thing.
>
> If you want to use 130 you should be using the RackInferringSnitch, if you
> want to use human names use either the SimpleSnitch or the
> PropertyFileSnitch. Property File Snitch has a default catch all DC, see the
> cassandra-topology.properties file.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 15/09/2011, at 9:43 AM, Anthony Ikeda wrote:
>
> Okay, in a previous post, it was stated that I could use a
> NetworkTopologyStrategy in a singel data centre by setting up my keyspace
> with:
>
> create keyspace KeyspaceDEV
>
>     with placement_strategy =
> 'org.apache.cassandra.locator.NetworkTopologyStrategy'
>
>     and strategy_options=[{datacenter1:3}];
>
>
> Whereby my understanding is that:
>
> [{datacenter1:3}]
>
> represents:
>
>
>    - 1 Datacentre
>    - 3 nodes in that datacentre
>
> My infrastructure team were recommended to instead of use "datacenter1" to
> use the second value in the IP address:
> x.130.x.x
>
> [{130:3}]
>
> However, when trying to access the keyspace the following error was return:
>
> "May not be enough replicas present to handle consistency level"
> When I rebuilt the keyspace using the "datacenter1" semantic, it worked
> fine.
>
> My guess is that there is some correlation between the "130" value and
> either the rpc_address or listen_address. Am I correct in thinking this?
>
> I don't have access to the se configurations so I'm just going out on a
> whim here trying to figure out why using the "130" form the IP address would
> cause the error.
>
> Anthony
>
>
>
>
>

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