On Mon, Jul 27, 2009 at 9:42 PM, Geoffry Roberts <[email protected]>wrote:
> All, > > I am attempting to run my first map reduce job and I am getting the > following error. Does anyone know what it means? > > Shuffle Error: Exceeded MAX_FAILED_UNIQUE_FETCHES; bailing-out. > > After the maps are complete, reducers need to fetch the intermediate map-outputs so they can reduce() them (this is part of the "shuffle" phase). It seems like in your case, for some reason the reducers are unable to fetch the map-ouputs from the corresponding TaskTracker nodes even after MAX_FAILED_UNIQUE_FETCHES attempts. The TaskTrackers (actually a Jetty webserver running on them) are responsible for serving these map-outputs. -- Harish Mallipeddi http://blog.poundbang.in
