On Fri, Sep 18, 2015 at 10:29 AM, Iranga Muthuthanthri <[email protected]>
wrote:

>
>
> On Wed, Sep 16, 2015 at 12:22 PM, Malith Dhanushka <[email protected]>
> wrote:
>
>> Hi Sachith,
>>
>> +1 for using Hector and this will be a handy utility tool for DAS as
>> well. Because anyone who has Cassandra raw data can use this tool to
>> persist them in any file store facilitated by DAL. Given the fact, is it
>> worth the effort implementing this as a generic tool? WDUT?
>>
>
> for clarification on 'any file store facilitated by DAL '  means RDBMS,
> HBase and Cassandra ?
>

That's correct Iranga.



>> Thanks,
>> Malith
>>
>> On Wed, Sep 16, 2015 at 10:54 AM, Sachith Withana <[email protected]>
>> wrote:
>>
>>> Hi all,
>>>
>>> DAS migration tool is used to migrate the data from BAM deployments to
>>> DAS.
>>>
>>> Basically how it works is, it reads the records from Cassandra column
>>> families (of BAM) and inserts them to DAS analytics tables at the Data
>>> Access Layer (DAL) level.
>>>
>>> BAM uses Cassandra 1.x versions and the previous iteration of the tool
>>> was using CQL to get all the records from a given column family and insert
>>> them to DAL.
>>>
>>> But for large amounts of records read from BAM caused CQL to throw an
>>> OutOfMemory exception from the GC, since CQL is trying to load all the
>>> records to memory ( using select * from *tableName* ).
>>>
>>> Therefore we had to introduce pagination support by rewriting the
>>> migration tool using the Hector Driver.
>>>
>>> Now the hector based implementation reads in records batch-wise ( the
>>> batch size is configurable) and inserts to DAL thus taking out the
>>> possibility of running out of memory.
>>>
>>> Thanks,
>>> Sachith
>>> --
>>> Sachith Withana
>>> Software Engineer; WSO2 Inc.; http://wso2.com
>>> E-mail: sachith AT wso2.com
>>> M: +94715518127
>>> Linked-In: <http://goog_416592669>
>>> https://lk.linkedin.com/in/sachithwithana
>>>
>>> _______________________________________________
>>> Architecture mailing list
>>> [email protected]
>>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture
>>>
>>>
>>
>>
>> --
>> Malith Dhanushka
>> Senior Software Engineer - Data Technologies
>> *WSO2, Inc. : wso2.com <http://wso2.com/>*
>> *Mobile*          : +94 716 506 693
>>
>> _______________________________________________
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>>
>>
>
>
> --
> Thanks & Regards
>
> Iranga Muthuthanthri
> (M) -0777-255773
> Team Product Management
>
>
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>
>


-- 
Malith Dhanushka
Senior Software Engineer - Data Technologies
*WSO2, Inc. : wso2.com <http://wso2.com/>*
*Mobile*          : +94 716 506 693
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