Multiple mapper tasks. Combiner is independent from this functionality I think. Combiner merges rows with the same key. It can work on both single mapper output and multiple mapper outputs together.
Zheng -----Original Message----- From: Zhong Wang [mailto:[email protected]] Sent: Sunday, August 16, 2009 8:42 AM To: [email protected] Subject: Re: merging multiple mapper's outputs On Sun, Aug 16, 2009 at 10:00 AM, Zheng Shao<[email protected]> wrote: > Does hadoop have the capability of merging multiple mappers(on the same > node) output into a single one, to speed up the shuffling phase? Is there a > JIRA that I can find more information about it? Do you mean outputs from multiple mapper tasks or multiple mapper functions? Could Combiner help? -- Zhong Wang
