The scrits themselves will use ssh to connect to every machine (even localhost). It's up to you if you want to type the password everytime. For a pseudo-distributed system, I don't see the issue with configuring a local ssh access.
BUT Hadoop in itself does not require ssh. If you have a more appropriate way to start/stop the processes, you can write your own scripts. Regards Bertrand On Thu, May 16, 2013 at 6:02 PM, Mohammad Tariq <[email protected]> wrote: > Hello Raj, > > ssh is actually 2 things : > 1- ssh : The command we use to connect to remote machines - the client. > 2- sshd : The daemon that is running on the server and allows clients to > connect to the server. > ssh is pre-enabled on Linux, but in order to start sshd daemon, we need to > install ssh first. > > To start the Hadoop daemons you have to make ssh passwordless and issue > bin/start-dfs.sh and bin/start-mapred.sh. > > You might find this > link<http://cloudfront.blogspot.in/2012/07/how-to-setup-and-configure-ssh-on-ubuntu.html#.UZUCkUAW38s> > useful. > > Warm Regards, > Tariq > cloudfront.blogspot.com > > > On Thu, May 16, 2013 at 9:26 PM, Raj Hadoop <[email protected]> wrote: > >> Hi, >> >> I am a bit confused here. I am planning to run on a single machine. >> >> So what should i do to start hadoop processes. How should I do an SSH? >> Can you please breifly explain me what SSH is? >> >> Thanks, >> Raj >> *From:* Jay Vyas <[email protected]> >> *To:* "[email protected]" <[email protected]> >> *Cc:* Raj Hadoop <[email protected]> >> *Sent:* Thursday, May 16, 2013 11:34 AM >> *Subject:* Re: Configuring SSH - is it required? for a psedo >> distriburted mode? >> >> Actually, I should amend my statement -- SSH is required, but >> passwordless ssh (i guess) you can live without if you are willing to enter >> your password for each process that gets started. >> >> But Why wouldn't you want to implement passwordless ssh in a pseudo >> distributed cluster ? Its very easy to implement on a single node: >> >> cat ~/.ssh/id_rsa.pub /root/.ssh/authorized_keys >> >> >> >> >> On Thu, May 16, 2013 at 11:31 AM, Jay Vyas <[email protected]> wrote: >> >> Yes it is required -- in psuedodistributed node the jobtracker is not >> necessarily aware that the task trackers / data nodes are on the same >> machine, and will thus attempt to ssh into them when starting the >> respective deamons etc (i.e. start-all.sh) >> >> >> On Thu, May 16, 2013 at 11:21 AM, kishore alajangi < >> [email protected]> wrote: >> >> When you start the hadoop procecess, each process will ask the password >> to start, to overcome this we will configure SSH if you use single node or >> multiple nodes for each process, if you can enter the password for each >> process Its not a mandatory even if you use multiple systems. >> >> Thanks, >> Kishore. >> >> >> On Thu, May 16, 2013 at 8:24 PM, Raj Hadoop <[email protected]> wrote: >> >> Hi, >> >> I have a dedicated user on Linux server for hadoop. I am installing it in >> psedo distributed mode on this box. I want to test my programs on this >> machine. But i see that in installation steps - they were mentioned that >> SSH needs to be configured. If it is single node, I dont require it >> ...right? Please advise. >> >> I was looking at this site >> >> http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-single-node-cluster/ >> >> It menionted like this - >> " >> Hadoop requires SSH access to manage its nodes, i.e. remote machines plus >> your local machine if you want to use Hadoop on it (which is what we want >> to do in this short tutorial). For our single-node setup of Hadoop, we >> therefore need to configure SSH access to localhost for the hduser user >> we created in the previous section. >> " >> >> Thanks, >> Raj >> >> >> >> >> >> >> -- >> Jay Vyas >> http://jayunit100.blogspot.com/ >> >> >> >> >> -- >> Jay Vyas >> http://jayunit100.blogspot.com/ >> >> >> >
