-Re: MapReduce to load data in HBase
Mohammad Tariq 2013-02-07, 11:40
You might find these links helpful :
On Thu, Feb 7, 2013 at 5:05 PM, Panshul Whisper <[EMAIL PROTECTED]>wrote:
> 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
>>> 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
> Ouch Whisper