Are you calling mos.close() in your Mapper's close() method? For example:
public static class Map extends MapReduceBase implements Mapper {
(... all the stuff you already have ...)
@Override
public void close() throws IOException {
mos.close();
}
}
On Wed, Jul 8, 2009 at 4:28 AM, Johnson Chen <[email protected]> wrote:
> Hi ,
> I want to output data from each Mapper , so I write the following code.
>
> public static class Map extends MapReduceBase implements Mapper {
> private MultipleOutputs mos ;
>
> public void configure(JobConf job) {
> mos = new MultipleOutputs(job);
> }
>
> mos.getCollector("hashtable", reporter).collect( new Text(
> output_data ) , new Text(""));
> ...
> }
>
> I got hashtable-m-00000 ~ hahashtable-m-00009 files.
>
> But when I looked into these files , they were all empty .
>
> However , when I put MultipleOutputs in Reducer , it works!
>
>
> Why ? Can Mapper use MultipleOutputs ?
>
>
>
>
> --
> Best wishes,
> Johnson Chen
>
