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From Patricio Echag├╝e <patric...@gmail.com>
Subject Re: Consistency Level of CLI
Date Tue, 23 Mar 2010 00:02:21 GMT
Hi all, is there any documentation for:

 ConsistencyLevel.DCQUORUM  and  ConsistencyLevel.DCQUORUMSYNC ?

DC = Data Center ?

Thanks

On Thu, Feb 25, 2010 at 12:12 PM, Masood Mortazavi <
masoodmortazavi@gmail.com> wrote:

> From the code, it appears that for "get" the default is ONE.
>   Column column = thriftClient_.get(tableName, key, path,
> ConsistencyLevel.ONE).column
> - m.
>
>
> On Thu, Feb 25, 2010 at 11:08 AM, Masood Mortazavi <
> masoodmortazavi@gmail.com> wrote:
>
>>
>>
>> What is the write and read consistency level for the CLI tool
>> "cassandra-cli" ?
>>
>> Do the "set" and "get" commands in the "cli" allow the Consistency Level
>> to be specified for a given "set" or "get"?
>>
>> Is there a current specification of CLI anywhere on the wiki?
>>
>> ( How are JIRA's related to the CLI tagged in the JIRA system assuming
>> they are "tagged" separately? In other words, is there an identifier for
>> them? )
>>
>> Regards,
>> m.
>>
>> ==========================
>> The Cassandra "API" describes write and read consistency levels as
>> follows:
>> http://wiki.apache.org/cassandra/API
>> Write
>>
>> *Level*
>>
>> *Behavior*
>>
>> ZERO
>>
>> Ensure nothing. A write happens asynchronously in background
>>
>> ANY
>>
>> (Coming in 0.6) Ensure that the write has been written to at least 1 node,
>> including hinted recipients.
>>
>> ONE
>>
>> Ensure that the write has been written to at least 1 node's commit log and
>> memory table before responding to the client.
>>
>> QUORUM
>>
>> Ensure that the write has been written to <ReplicationFactor> / 2 + 1nodes
before responding to the client.
>>
>> ALL
>>
>> Ensure that the write is written to all <ReplicationFactor> nodes before
>> responding to the client. Any unresponsive nodes will fail the operation.
>>
>> Read
>>
>> *Level*
>>
>> *Behavior*
>>
>> ZERO
>>
>> Not supported, because it doesn't make sense.
>>
>> ANY
>>
>> Not supported. You probably want ONE instead.
>>
>> ONE
>>
>> Will return the record returned by the first node to respond. A
>> consistency check is always done in a background thread to fix any
>> consistency issues when ConsistencyLevel.ONE is used. This means
>> subsequent calls will have correct data even if the initial read gets an
>> older value. (This is called read repair.)
>>
>> QUORUM
>>
>> Will query all storage nodes and return the record with the most recent
>> timestamp once it has at least a majority of replicas reported. Again, the
>> remaining replicas will be checked in the background.
>>
>> ALL
>>
>> Will query all storage nodes and return the record with the most recent
>> timestamp once all nodes have replied. Any unresponsive nodes will fail the
>> operatio
>>
>>
>


-- 
Patricio.-

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