If you're using the start-dfs.sh script, it's ssh'ing into every machine in conf/masters to start a SecondaryNameNode instance. The NameNode itself is started locally. It then ssh's into every machine in conf/slaves to start a DataNode instance.
Similarly, the JT is started locally by start-mapred.sh. But it sshs to every machine in conf/slaves to start a TaskTracker. - Aaron On Sat, Apr 4, 2009 at 6:36 AM, Foss User <[email protected]> wrote: > I have a namenode and job tracker on two different machines. > > I see that a namenode tries to do an ssh log into itself (name node), > job tracker as well as all slave machines. > > However, the job tracker tries to do an ssh log into the slave > machines only. Why this difference in behavior? Could someone please > explain what is going on behind the scenes? >
