Seems like it is supported in Hado开发者_StackOverflow中文版op(reference), but I dont know how to use this.
Intuitively, hadoop is doing something like this to distribute keys to mappers, using python-esque pseudocode.
API only provides methods to increase a counter in Mapper or Reducer. Is there a way to just set it? or increment it\'s value only once irrespective 开发者_如何转开发of the number of times mappers and
I tried to use lzo in my hive script, but got this error message. It seemed that I did not have the class for lzo in the classpath.
How to control file assignation in different slave in hadoop distributed system? Is it possible to write 2 or more file in hadoo开发者_运维知识库p as map reduce task Simultaneously?
I am w开发者_C百科riting an indexing app for MapReduce. I was able to split inputs with NLineInputFormat, and now I\'ve got few hundred mappers in my app. However, only 2/mashine of those are active a
Hadoop job is asking to disable safe mode manually. I开发者_如何学运维t says the resources are not available. How to disable safe mode?You can leave safemode by using the following command:
I am new to hadoop. I have set up a 2 node cluster. 开发者_如何学CHow to run 2 jobs parallely in hadoop.
I\'m trying to set the number of map tasks to run in hadoop 0.20 environment. I am using the old api. Here are the options I\'ve tried so far:
I want to have hie开发者_如何学编程rarchical keys like: app:page:user:item = value (where : indicates concatenating with a delimiter). I understand that I can quickly find all the items that that user