Luiz, Though it is possible to 'hint' this by tweaking the InputSplits passed from the job, the default schedulers of Hadoop do not make any such guarantees and hence this isn't possible unless you write your own complete scheduler, an exercise that wouldn't suit production deployments unless you also test your scheduler intensively for other types of workloads.
Why do you even need such a thing? For processing purposes or otherwise? I'm hoping its not a monitoring sort of hack you're trying to do. On Thu, Mar 29, 2012 at 5:55 AM, Luiz Carlos Muniz <lcmu...@gmail.com> wrote: > Hi, > > Is there any way to ensure the execution of a map on all nodes of a > clusterin a way that each node run the map once and only once. That is, I > would use Hadoop to execute a method on all nodes in the cluster. Without > the possibility that the method execute twice in the same node even if > another node fails. > > I already set mapred.tasktracker.map.tasks.maximum to 1 and > mapred.max.jobs.per.node to 1 but still, if a node fails, another node that > has > carried out a map before run the map again to meet the absence of which > failed. > > Luiz Carlos Melo Muniz > > Luiz Carlos Melo Muniz > > -- Harsh J
