hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Allen Wittenauer ...@apache.org>
Subject Re: definition of slots in Hadoop scheduling
Date Sat, 12 Mar 2011 16:34:26 GMT

(Removing common-dev, because this isn't really a dev question)

On Feb 25, 2011, at 5:52 AM, bikash sharma wrote:

> Hi,
> How is task slot in Hadoop defined with respect to scheduling a map/reduce
> task on such slots available on TaskTrackers?

	On a TaskTracker, one sets how many maps and reduces one wants to run on that node.  The
JobTracker is informed of this value.  When a job is getting scheduled, it compares the various
tasks's input to see if a DataNode is providing a matching block.  If a block exists or is
nearby, the task is scheduled on that node.

View raw message