See also https://issues.apache.org/jira/browse/MAPREDUCE-434 which has a patch for this issue.
Cheers, Tom On Mon, May 2, 2011 at 5:13 PM, jason <urg...@gmail.com> wrote: > I am attaching the originals so you could figure out the diffs on your own :) > > On 5/2/11, Dmitriy Lyubimov <dlie...@gmail.com> wrote: >> Thanks a bunch! >> >> (is there any chance you could do a diff only ? ) >> >> -d >> >> On Mon, May 2, 2011 at 4:47 PM, jason <urg...@gmail.com> wrote: >>> Dmitriy, >>> >>> I remember I had the same problem with local jobs when I tried to >>> debug my multi-reducer use cases. So had to create this small patch >>> that resolves the issue. >>> You can put these classes into org.apache.hadoop.mapred package in >>> your local project and make sure they preceed Hadoop's jars in the >>> class path. >>> >>> My patch is based on Cloudera 0.20.2+320 release. >>> >>> Hope this helps. >>> >>> >>> On 5/2/11, Dmitriy Lyubimov <dlie...@gmail.com> wrote: >>>> Hi, >>>> >>>> i was trying to create a test based on mapreduce job in a local mode >>>> testing various partitioning issues. >>>> >>>> But curiously, whenever i switch mapreduce into local node, i can't >>>> seem to be able to configure multiple reduce tasks. >>>> >>>> Indeed, upon some investigation i found that the following fragment in >>>> LocalJobRunner resets all reducers to 1 : >>>> >>>> /* 177 */ int numReduceTasks = this.job.getNumReduceTasks(); >>>> /* 178 */ if ((numReduceTasks > 1) || (numReduceTasks < 0)) >>>> /* */ { >>>> /* 180 */ numReduceTasks = 1; >>>> /* 181 */ this.job.setNumReduceTasks(1); >>>> /* */ } >>>> /* 183 */ outputCommitter.setupJob(jContext); >>>> /* 184 */ this.status.setSetupProgress(1.0F); >>>> /* */ >>>> /* 186 */ Map mapOutputFiles = new HashMap(); >>>> /* */ >>>> >>>> >>>> Is this a fundamental limitation of the local mapreduce mode? what if >>>> i need to write up a unit test that checks various partitioning >>>> functions? Is there a workaround? >>>> >>>> Also, i don't remember these problems when writing tests based on >>>> local mapreduce in previous versions (this is cdh3b4) , although i >>>> cannot be sure if i ran into exactly same situation before. >>>> >>>> thanks. >>>> -Dmitriy >>>> >>> >> >