In the map method, records would be ignored with no output.collect() or context.write().
Or you just delete output file from reducer 2 at the end of job. the reducer 2's result file is "part-r-00002". Drake 민영근 Ph.D kt NexR On Wed, Mar 11, 2015 at 9:43 PM, Fabio C. <anyte...@gmail.com> wrote: > As far as I know the code running in each reducer is the same you specify > in your reduce function, so if you know in advance the features of the data > you want to ignore you can just instruct reducers to do so. > If you are able to tell whether or not to keep an entry at the beginning, > you can filter them out within the map function. > I could think of a wordcount example where we tell the map phase to ignore > all the words starting with a specific letter... > What kind of data are you processing and what is the filtering condition? > Anyway I'm sorry I can't help with the actual code, but I'm not really > into this right now. > > On Wed, Mar 11, 2015 at 12:13 PM, xeonmailinglist-gmail < > xeonmailingl...@gmail.com> wrote: > >> Maybe the correct question is, how can I filter data in mapreduce in >> Java? >> >> >> >> On 11-03-2015 10:36, xeonmailinglist-gmail wrote: >> >> To exclude data to a specific reducer, should I build a partitioner that >> do this? Should I have a map function that checks to which reduce task the >> output goes? >> >> Can anyone give me some suggestion? >> >> And by the way, I really want to exclude data to a reduce task. So, I >> will run more than 1 reducer, even if one of them does not get input data. >> >> >> On 11-03-2015 10:28, xeonmailinglist-gmail wrote: >> >> Hi, >> >> I have this job that has 3 map tasks and 2 reduce tasks. But, I want to >> excludes data that will go to the reduce task 2. This means that, only >> reducer 1 will produce data, and the other one will be empty, or even it >> doesn't execute. >> >> How can I do this in MapReduce? >> >> [image: Example Job Execution] >> >> >> Thanks, >> >> -- >> -- >> >> >> -- >> -- >> >> >> -- >> -- >> >> >
