Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
HDFS, mail # user - What is the preferred way to pass a small number of configuration parameters to a mapper or reducer


Copy link to this message
-
Re: What is the preferred way to pass a small number of configuration parameters to a mapper or reducer
Michel Segel 2012-12-28, 22:19
Sounds like someone is cheating on a test...

Sent from a remote device. Please excuse any typos...

Mike Segel

On Dec 28, 2012, at 3:10 PM, Ted Dunning <[EMAIL PROTECTED]> wrote:

> Answer B sounds pathologically bad to me.
>
> A or C are the only viable options.
>
> Neither B nor D work.  B fails because it would be extremely hard to get the right records to the right components and because it pollutes data input with configuration data.  D fails because statics don't work in parallel programs.
>
>
> On Fri, Dec 28, 2012 at 12:17 AM, Kshiva Kps <[EMAIL PROTECTED]> wrote:
>>
>> Which one is current ..
>>
>> What is the preferred way to pass a small number of configuration parameters to a mapper or reducer?
>>  
>>  
>> A.  As key-value pairs in the jobconf object.
>>  
>> B.  As a custom input key-value pair passed to each mapper or reducer.
>>  
>> C.  Using a plain text file via the Distributedcache, which each mapper or reducer reads.
>>  
>> D.  Through a static variable in the MapReduce driver class (i.e., the class that submits the MapReduce job).
>>  
>> Answer: B
>