-Re: MapReduce to load data in HBase
Panshul Whisper 2013-02-07, 11:35
Thank you for the reply.
1. I cannot serialize the Json and store it as a whole. I need to extract
individual values and store them as later I need to query the stored values
in various aggregation algorithms.
2. Can u please point me in direction where I can find out how to write a
data type to be Writable+Comparable. I will look into Avro, but I prefer to
write my owm data type.
3. I will look into MR counters.
On Thu, Feb 7, 2013 at 12:28 PM, Mohammad Tariq <[EMAIL PROTECTED]> wrote:
> Hello Panshul,
> My answers :
> 1- You can serialize the entire jSON into a byte[ ] and store it in a
> cell.(Is it important for you extract individual values from your JSON and
> then put them into the table?)
> 2- You can write your own datatype to pass your object to the reducer.
> But, it must be a Writable+Comparable. Alternatively you van use Avro.
> 3- For generating unique keys, you can use MR counters.
> Warm Regards,
> On Thu, Feb 7, 2013 at 4:52 PM, Panshul Whisper <[EMAIL PROTECTED]>wrote:
>> I am trying to write MapReduce jobs to read data from JSON files and load
>> it into HBase tables.
>> Please suggest me an efficient way to do it. I am trying to do it using
>> Spring Data Hbase Template to make it thread safe and enable table locking.
>> I use the Map methods to read and parse the JSON files. I use the Reduce
>> methods to call the HBase Template and store the data into the HBase tables.
>> My questions:
>> 1. Is this the right approach or should I do all of the above the Map
>> 2. How can I pass the Java Object I create holding the data read from the
>> Json file to the Reduce method, which needs to be saved to the HBase table?
>> I can only pass the inbuilt data types to the reduce method from my mapper.
>> 3. I thought of using the distributed cache for the above problem, to
>> store the object in the cache and pass only the key to the reduce method.
>> But how do I generate the unique key for all the objects I store in the
>> distributed cache.
>> Please help me with the above. Please tell me if I am missing some detail
>> or over looking some important detail.
>> Thanking You,
>> Ouch Whisper