NameNode as datanode (error)
I’ve got a situation where the namenode is being used as a datanode and mappers are being run there. Not good. For some reason I HoClient.getActiveTrackerNames() is returning the Namenode as well as all datanodes. What configuration mess up could cause this?
I’m trying to get Sqoop to run my mappers, exactly one per Datanode. I’ve written my InputFormat class to create splits with exactly one hostname (datanodes only) per split, yet am being ignored. Why is the Jobtracker ignoring my splits? The host names I’m submitting are exactly as getActiveTrackerNames() returns, sans the :nnnnn, as suggested in getActiveServersList() by Boris Lublinsky and Mike Segel. btw: this system works in that other Hadoop environment. This is an Amazon hosted system.
Support from the Experts
A HDP Support Subscription connects you experts with deep experience running Apache Hadoop in production, at-scale on the most demanding workloads.
Become HDP Certified
Real world training designed by the core architects of Hadoop. Scenario-based training courses are available in-classroom or online from anywhere in the world