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MapReduce >> mail # user >> Reducer - getMapOutput

Grandl Robert 2012-07-30, 16:10
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Re: Reducer - getMapOutput
Hey Robert,

 Can you pls share what you are trying to do?


On Jul 30, 2012, at 9:10 AM, Grandl Robert wrote:

> Hi,
> I am trying to modify the code for data transfer of intermediate output.
> In this respect, on the reduce side in getMapOuput I want to have the connection with the TaskTracker(setupSecureConnection), but then on doGet the TaskTracker to be able to delay the response back to the client. I tried with Thread.sleep(time), before setting up the response.setHeader(FROM_MAP_TASK, mapId) and the subsequent headers/content. But it seems the reducer will continue to read the headers immediately and get NULL.
> Do you know how can I do the reducer to wait for TaskTracker to update this information before reading it. I tried with a while loop and reading the connection.getHeaderField(...) till not null but seems it always remains in the loop :(.
> Probably is more a HttpServlet related problem but I am not very familiar with that.
> Do you have any idea how can I do it ?
> Thanks,
> Robert

Arun C. Murthy
Hortonworks Inc.
Grandl Robert 2012-07-30, 17:56