Hi, You can call context.write() multiple times in the Reduce(), to emit more than one row.
If you are creating the Puts in the Map function then you need to setMapSpeculativeExecution(false) on the job conf, or else Hadoop *might* spawn more than 1 attempt for a given task, meaning you'll get duplicate data. HTH, Tim On Tue, Feb 28, 2012 at 3:51 PM, T Vinod Gupta <[email protected]> wrote: > Ben, > I didn't quite understand your concern? What speculative execution are you > referring to? > > thanks > vinod > > On Tue, Feb 28, 2012 at 6:45 AM, Ben Snively <[email protected]> wrote: > >> I think the short answer to that is yes, but the complex portion I would be >> worried about is the following: >> >> >> I guess along with that , how do manage speculative execution on the >> reducer (or is that only for map tasks)? >> >> I've always ended up creating import files and bringing it into HBase. >> >> Thanks, >> Ben >> >> On Tue, Feb 28, 2012 at 9:34 AM, T Vinod Gupta <[email protected] >> >wrote: >> >> > while doing map reduce on hbase tables, is it possible to do multiple >> puts >> > in the reducer? what i want is a way to be able to write multiple rows. >> if >> > its not possible, then what are the other alternatives? i mean like >> > creating a wider table in that case. >> > >> > thanks >> > >>
