What is a JobTracker in Hadoop? How many instances of JobTracker run on a Hadoop Cluster?
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. There is only One Job Tracker process run on any hadoop cluster. Job
Tracker runs on its own JVM process. In a typical production cluster its run on
a separate machine. Each slave node is configured with job tracker node
location. The JobTracker is single point of failure for the Hadoop MapReduce
service. If it goes down, all running jobs are halted. JobTracker in Hadoop
performs following actions