Re: How to get the number of node in cluster?

[George Datskos]

Hey Jason,

This should return the number of active tasktrackers in the cluster:
int numNodes = new JobClient(conf).getClusterStatus().getTaskTrackers()

Hi, all

As I have to run my MapReduce program on clusters of different size, and I would like the reducer number adapt to (0.95 * NodeNo. * mapred.tasktracker.reduce.tasks.maximum) automatically, so I was wondering how to get get the number of node in cluster in a MapReduce Job?

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YANG, Lin