Thank you very much, Bryan!
It is now clear for me, that in development mode I'll not start secondary
But in production it's better to have it.
2012/12/17 Bryan Beaudreault <[EMAIL PROTECTED]>
> You don't need a secondary name node. It creates snapshots of the name
> node metadata periodically, which helps to keep down the size of the edits
> files. If you don't run one, over time your edits files will grow. The
> next time you go to restart your namenode, it could take a very long time
> to start up if your edits are large. I recommend running one in
> production, to reduce the amount of downtime if you need to replace or
> restart your namenode. If that isn't a concern for you then you don't need
> On Mon, Dec 17, 2012 at 12:04 PM, Ivan Ryndin <[EMAIL PROTECTED]> wrote:
>> 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 $HADOOP_CONF_DIR start namenode
>> "$bin"/hadoop-daemons.sh --config $HADOOP_CONF_DIR start datanode
>> "$bin"/hadoop-daemons.sh --config $HADOOP_CONF_DIR --hosts masters start
>> 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,
Ivan P. Ryndin