Re: help! Octave, connecting laptops to "supercomputers"

[Sergei Steshenko]

----- Original Message -----
> From: Pedro <address@hidden>
> To: address@hidden
> Cc: 
> Sent: Thursday, January 31, 2013 3:00 AM
> Subject: Re: help! Octave, connecting laptops to "supercomputers"
> 
> First of all, Writing this mail I wanted to know what use octavian
> people like me (or not) when need to work with hard processes. 4/4 for
> going in "ssh -X", well, I have to re-think on that!
> 
> I said no to "ssh -X" because I'm looking for alternatives on
> connecting with computer/computers that process the data.
> 
> - I've never used. (read last line of this mail)
> 
> - from ssh -X I read that is innerently insecure, because run a root
> process: the X server, read this (old) review about this [1].
> 
> - Also, because is slow (or inefficient), that's because is encrypting
> all the communications to the server.
> But I only want to "pass the code strictly necessary".
> Because if I use the ssh connection as a workstation it's excessive
> for what I want.
> Imagine looking images, sound or video with a ssh connection in a
> "streaming way".
> I could do rsync? ... Yes, but are things that take you off your
> concentration, no? It means, that make you thing on two machines
> constantly.
> 
> I would like to imagine "one machine", could be with virtualization?
> cloud computing? "p2p processing" ? Assymetric processing?
> 
> I don't understand a lot how it works distcc, but see this:
> compilation of kernel distributed: the guy is in his computer, and
> divide tasks to others, after it, they have his output file. [1]
> Compiling means that a personalized task (hardware, processor
> architecture...) but delivered to process by others
> 
> For "ssh -X" users, could they give some tricks to make life easier?
> 
> Thanks for reading!
> Pedro
> 
> [1] 
> https://padraic2112.wordpress.com/2007/07/09/bad-security-201-remote-x-sessions-over-ssh/
> [2] https://www.youtube.com/watch?v=WNXin-XoEDU
> 
> On Wed, Jan 30, 2013 at 2:06 AM, Ben Abbott <address@hidden> wrote:
>> 
>>  On Jan 29, 2013, at 6:50 PM, Pedro wrote:
>> 
>>>  Hi,
>>> 
>>>  I'm a laptop user & student of image, video, sound processing. 
> Laptops
>>>  have big limitations on processing big, complex data or algorithms but
>>>  are great as a "portable terminals to connect".
>>>  In my case, my laptop have a Intel Pentium M processor 1.2 GHz.
>>> 
>>>  I would like to prepare a "zombie" and strong Desktop 
> Computer to make
>>>  him work what I do in my laptop. ( But it could be also interesting to
>>>  do a small cloud of computers to distribute the work ! )
>>> 
>>>  This follows the phylosophy of paying a laptop for his portability,
>>>  and a desktop/server (fixed Computer) for processing. No, I don't 
> want
>>>  a ultrabook with intel i7, etc.
>>> 
>>>  Anyone would like to share his solution for this problem in Octave
>>>  (speficically) or in general (as a operative system)? Preferred
>>>  crossplatform solutions (If Windows or GNU/Linux users could give work
>>>  to him )
>>>  I see the BOINC app [0], but I don't know how can be used. Docs,
>>>  tutorials?? Here is a message in 2005, asking this in a similar way [1]
>>> 
>>>  Octave provides packages to work in parallel processing, multicores,
>>>  etc. [2]. But i'm not interested in this, because I want a 
> "standard
>>>  code" that anyone can execute (with his resources).
>>> 
>>>  Also I'm not interested in the solution of "ssh -X" (X 
> forwarding) or
>>>  with a full remote x server [3]with copies between computers with scp
>>>  or rsync / luckybackup
>>> 
>>>  Thanks,
>>>  Pedro
> 
>>  You've excluded many options ... what about remote desktop?
> 
> 
> 
> 
> On Wed, Jan 30, 2013 at 1:38 AM, Sergei Steshenko <address@hidden> 
> wrote:
>> 
>>  And what exactly is wrong with "ssh -X" ?
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://mailman.cae.wisc.edu/listinfo/help-octave
> 

AFAIK, modern X servers are not run as root.

But anyway, 'ssh -X ...' does not start a process running as 'root', it uses an 
existing one.

FWIW, you do not even need X server to run Octave, you need it for plotting - 
if you use it in your Octave program.

If you do not do plotting, you can use just 'ssh ...' - without '-X'.

And with some inconvenience you can do plotting on your laptop separately from 
your Octave session. And/or with some tricks in real time - if you write a 
special 'gnuplot' wrapper on your cluster which will invoke 'gnuplot' on your 
laptop - that's the beauty of having plotting implemented as a separate process.

Regards,
  Sergei.