Thanks..But, my 1st question is still unanswered. I have a 8 DN/TT machines and 1 NN machine. I want to set one of my DN/TT machine as SNN. How I have to configure my conf/*.xml files to achieve this ?
Thanks, Praveenesh On Mon, Dec 26, 2011 at 8:44 PM, Harsh J <ha...@cloudera.com> wrote: > (Answering beyond Uma's reply) > >> Can a DN also act as SNN, any pros and cons of having this configuration ? > > You can run SNN on a regular slave box if you can't have a dedicate a box, it > shouldn't be an issue for small clusters -- Do ensure its disk configuration > is proper, and its allocated near to the same heap as the NameNode is. > > For large clusters where the fsimage and periodic edits file sizes are > larger, it would be worth placing it on a separate box given SNN's > interactions. > > On 26-Dec-2011, at 7:53 PM, Uma Maheswara Rao G wrote: > >> Hey Praveenesh, >> >> You can start secondary namenode also by just giving the option ./hadoop >> secondarynamenode >> >> DN can not act as seconday namenode. The basic work for seconday namenode is >> to do checkpointing and getting the edits insync with Namenode till last >> checkpointing period. DN is to store the real data blocks physically. >> you need to configure correct namenode http address also for the >> secondaryNN, so that it can connect NN for checkpointing operations. >> http://hadoop.apache.org/common/docs/current/hdfs_user_guide.html#Secondary+NameNode >> You can configure secondary node IP in masters file, start-dfs.sh itself >> will start the SNN automatically as it starts DN and NN as well. >> >> also you can see >> http://www.cloudera.com/blog/2009/02/multi-host-secondarynamenode-configuration/ >> >> Regards, >> Uma >> ________________________________________ >> From: praveenesh kumar [praveen...@gmail.com] >> Sent: Monday, December 26, 2011 5:05 PM >> To: common-user@hadoop.apache.org >> Subject: Secondary Namenode on hadoop 0.20.205 ? >> >> Hey people, >> >> How can we setup another machine in the cluster as Secondary Namenode >> in hadoop 0.20.205 ? >> Can a DN also act as SNN, any pros and cons of having this configuration ? >> >> Thanks, >> Praveenesh >
