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From Jean Carlo <jean.jeancar...@gmail.com>
Subject Re: [EXTERNAL] Re: Getting Consistency level TWO when it is requested LOCAL_ONE
Date Fri, 12 Apr 2019 09:50:36 GMT
I think this jira

https://issues.apache.org/jira/browse/CASSANDRA-9895

Answer my question

Saludos

Jean Carlo

"The best way to predict the future is to invent it" Alan Kay


On Fri, Apr 12, 2019 at 10:04 AM Jean Carlo <jean.jeancarl48@gmail.com>
wrote:

> Hello Sean
>
> Well this is a little bit confusing. After digging into the doc, I found
> this old documentation of Datastax that says
> "First, we can dynamically adjust behavior depending on the cluster size
> and arrangement. Cassandra prefers to perform batchlog writes to two
> different replicas in the same datacenter as the coordinator."
>
> https://www.datastax.com/dev/blog/atomic-batches-in-cassandra-1-2
>
> Which may explain the message in the timeout. However I do not know if
> this information is still true. Someone know if this is still true?
>
> Reading the comments in
> https://issues.apache.org/jira/browse/CASSANDRA-9620 that says ' *Writing
> the batch log will always be done using CL ONE.*' Contradict what I
> understood from datastax's doc
>
> Yes I understood batches are not for speed. Still we are using it for a
> consistency need.
>
> @Mahesh Yes we do set the consistency like that
>
> Thank you
>
> Jean Carlo
>
> "The best way to predict the future is to invent it" Alan Kay
>
>
> On Thu, Apr 11, 2019 at 3:39 PM Durity, Sean R <
> SEAN_R_DURITY@homedepot.com> wrote:
>
>> https://issues.apache.org/jira/browse/CASSANDRA-9620 has something
>> similar that was determined to be a driver error. I would start with
>> looking at the driver version and also the RetryPolicy that is in effect
>> for the Cluster. Secondly, I would look at whether a batch is really needed
>> for the statements. Cassandra batches are for atomicity – not speed.
>>
>>
>>
>> Sean Durity
>>
>> Staff Systems Engineer – Cassandra
>>
>> MTC 2250
>>
>> #cassandra - for the latest news and updates
>>
>>
>>
>>
>>
>> *From:* Mahesh Daksha <dakshme@gmail.com>
>> *Sent:* Thursday, April 11, 2019 5:21 AM
>> *To:* user@cassandra.apache.org
>> *Subject:* [EXTERNAL] Re: Getting Consistency level TWO when it is
>> requested LOCAL_ONE
>>
>>
>>
>> Hi Jean,
>>
>>
>>
>> I want to understand how you are setting the write consistency level as
>> LOCAL ONE. That is with every query you mentioning consistency level or you
>> have set the spring cassandra config with provided consistency level.
>>
>> Like this:
>>
>> cluster.setQueryOptions(new
>> QueryOptions().setConsistencyLevel(ConsistencyLevel.valueOf(cassandraConsistencyLevel)));
>>
>>
>>
>> The only possibility i see of such behavior is its getting overridden
>> from some where.
>>
>>
>>
>> Thanks,
>>
>> Mahesh Daksha
>>
>>
>>
>> On Thu, Apr 11, 2019 at 1:43 PM Jean Carlo <jean.jeancarl48@gmail.com>
>> wrote:
>>
>> Hello everyone,
>>
>>
>>
>> I have a case where the developers are using spring data framework for
>> Cassandra. We are writing batches setting consistency level at LOCAL_ONE
>> but we got a timeout like this
>>
>>
>>
>> *Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
>> Cassandra timeout during BATCH_LOG write query at consistency TWO (2
>> replica were required but only 1 acknowledged the write)*
>>
>>
>>
>> Is it Cassandra that somehow writes to the *system.batchlog* using
>> consistency TWO or is it spring data that makes some dirty things behind
>> the scenes ?
>>
>> (I want to believe it is the second one)
>>
>>
>>
>> Cheers
>>
>>
>>
>> Jean Carlo
>>
>>
>> "The best way to predict the future is to invent it" Alan Kay
>>
>>
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