Yes as Mariappan has already pointed out; the sort is pluggable so the plug-in can also nullify it. See [1] for an example implementation of the MapOutputCollector interface (class MapOutputCopier) to start with. Per Mariappan, this does not do any sorting, but only merges.
[1] - http://svn.apache.org/repos/asf/hadoop/common/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestMerge.java On Tue, Apr 23, 2013 at 2:00 PM, Samaneh Shokuhi <[email protected]> wrote: > Hi Harsh, > That is nice if branch-2 included that .Just one thing i want to be sure > about that .In this patch MAPREDUCE-4807 (branch-2) , sort in mapper is > avoided ? Becouse i need a version of hadoop without sorting part in mapper > and thats the reason i wanted to modify MapTask to disable the mapper sort > .Do you think branch-2 is appropriate version for me ? > > Samaneh > > > On Tue, Apr 23, 2013 at 10:01 AM, Harsh J <[email protected]> wrote: > >> Note that the Reducer also does a merge sort over the acquired map >> data; but am not sure if you looked there as well. >> >> Mariappan's pointed JIRA (MAPREDUCE-4807) is already available in the >> 2.0.3+ releases out today and in the current branch-2. It would be >> simpler to reuse that than do these modifications. >> >> On Sun, Apr 21, 2013 at 5:24 PM, Samaneh Shokuhi >> <[email protected]> wrote: >> > Hi All, >> > I have modified the MapTask.java file and tried to disable sort part for >> > some reasons . I have removed this line >> > *sorter.sort(MapOutputBuffer.this, kvstart, endPosition, reporter); *in >> > sortAndSpill method but no changes seen in result. I have expected to get >> > unsorted keys as mapper output but was not like that. >> > >> > My question is did i perform right action to disable sort or something >> else >> > needs to be done ? >> > >> > Samaneh >> >> >> >> -- >> Harsh J >> -- Harsh J
