Thursday, December 15, 2011

How to start CheckPoint NameNode in Hadoop 0.23 release?

Prior to 0.23 release the masters file in the  conf folder of Hadoop installation had the list of host names on which the CheckPoint NN has to be started. But, with the 0.23 release the masters file is not used anymore, the dfs.namenode.secondary.http-address key has to be set to ip:port in hdfs-site.xml. CheckPoint NN can be started using the sbin/ start secondarynamenode command. Run jps command to make sure that the CheckPoint NN is running and also check the corresponding log file also for any errors.

BTW, Secondary NN is being referred to as CheckPoint NN. But, the code is still using Secondary NN and people still refer it as Secondary NN.

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