Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Threaded View
MapReduce >> mail # user >> Is it necessary to run secondary namenode when starting HDFS?


Copy link to this message
-
Is it necessary to run secondary namenode when starting HDFS?
Hi all,

is it necessary to run secondary namenode when starting HDFS?
I am dealing with Hadoop 1.1.1.
Looking at script $HADOOP_HOME/bin/start_dfs.sh
There are next lines in this file:

# start dfs daemons
# start namenode after datanodes, to minimize time namenode is up w/o data
# note: datanodes will log connection errors until namenode starts
"$bin"/hadoop-daemon.sh --config $HADOOP_CONF_DIR start namenode
$nameStartOpt
"$bin"/hadoop-daemons.sh --config $HADOOP_CONF_DIR start datanode
$dataStartOpt
"$bin"/hadoop-daemons.sh --config $HADOOP_CONF_DIR --hosts masters start
secondarynamenode

 So, will HDFS work if I turn off starting of secondarynamenode ?

I do ask this because I am playing with Hadoop on two-node cluster only
(and machines in cluster do not have much RAM and disk space), and thus
don't want to run unnecessary processes.

--
Best regards,
Ivan P. Ryndin,
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB