Tom, Thanks for your help.
On Sat, Feb 6, 2010 at 9:01 AM, Tom White <[email protected]> wrote: > Hi Jeff, > > InputSplit in the new MapReduce API (in the o.a.h.mapreduce package) > does not implement Writable since splits can be serialized using any > serialization framework - e.g. Java object serialization. You can see > where splits are serialized at JobSplitWriter.writeNewSplits() and > deserialized on the task node at MapTask.getSplitDetails(). This is in > contrast to the old API which mandated that InputSplits had to be > Writable. > > Cheers, > Tom > > On Fri, Feb 5, 2010 at 11:09 PM, Jeff Zhang <[email protected]> wrote: > > Hi all, > > > > I look at the source code of Hadoop, and found that the InputSplit did > not > > implements Writable. As my understanding, InputSplit will been transfered > to > > each TT and then deserialized. So it should implement the Writable > > interface. And I check each implementation of InputSplit, actually all > the > > sub-classes implement the Writable interface. So I think it would be > better > > to to let the abstract class InputForamt implement the Writable, then > users > > won't forget to implement the method write(DataOutput out) and > > readFields(DataInput in) if he wants to write a customized InputSplit. > > > > > > -- > > Best Regards > > > > Jeff Zhang > > > -- Best Regards Jeff Zhang
