WHat Joey said is correct for both apache and cloudera distros. The DN/TT daemons will connect to the NN/JT using the config files. The master and slave files are used for starting the correct daemons.
>________________________________ > From: anil gupta <anilg...@buffalo.edu> >To: common-user@hadoop.apache.org; Raj Vishwanathan <rajv...@yahoo.com> >Sent: Thursday, March 1, 2012 5:42 PM >Subject: Re: Adding nodes > >Whatever Joey said is correct for Cloudera's distribution. For same, I am >not confident about other distribution as i haven't tried them. > >Thanks, >Anil > >On Thu, Mar 1, 2012 at 5:10 PM, Raj Vishwanathan <rajv...@yahoo.com> wrote: > >> The master and slave files, if I remember correctly are used to start the >> correct daemons on the correct nodes from the master node. >> >> >> Raj >> >> >> >________________________________ >> > From: Joey Echeverria <j...@cloudera.com> >> >To: "common-user@hadoop.apache.org" <common-user@hadoop.apache.org> >> >Cc: "common-user@hadoop.apache.org" <common-user@hadoop.apache.org> >> >Sent: Thursday, March 1, 2012 4:57 PM >> >Subject: Re: Adding nodes >> > >> >Not quite. Datanodes get the namenode host from fs.defalt.name in >> core-site.xml. Task trackers find the job tracker from the >> mapred.job.tracker setting in mapred-site.xml. >> > >> >Sent from my iPhone >> > >> >On Mar 1, 2012, at 18:49, Mohit Anchlia <mohitanch...@gmail.com> wrote: >> > >> >> On Thu, Mar 1, 2012 at 4:46 PM, Joey Echeverria <j...@cloudera.com> >> wrote: >> >> >> >>> You only have to refresh nodes if you're making use of an allows file. >> >>> >> >>> Thanks does it mean that when tasktracker/datanode starts up it >> >> communicates with namenode using master file? >> >> >> >> Sent from my iPhone >> >>> >> >>> On Mar 1, 2012, at 18:29, Mohit Anchlia <mohitanch...@gmail.com> >> wrote: >> >>> >> >>>> Is this the right procedure to add nodes? I took some from hadoop wiki >> >>> FAQ: >> >>>> >> >>>> http://wiki.apache.org/hadoop/FAQ >> >>>> >> >>>> 1. Update conf/slave >> >>>> 2. on the slave nodes start datanode and tasktracker >> >>>> 3. hadoop balancer >> >>>> >> >>>> Do I also need to run dfsadmin -refreshnodes? >> >>> >> > >> > >> > >> > > > >-- >Thanks & Regards, >Anil Gupta > > >