[Paraview] paraview - client-server

[burlen]

Nice, thanks for the clarification. I am guessing that your example 
should probably be the recommended approach rather than the portfwd 
method suggested on the PV wiki. :) I took the initiative to add it to 
the Wiki. KW let me know if this is not the case!

    http://paraview.org/Wiki/Reverse_connection_and_port_forwarding#Reverse_connection_over_an_ssh_tunnel

Would you mind taking a look to be sure I didn't miss anything or bollix 
it up?

The sshd config options you mentioned may be why your method doesn't 
work on the Pleiades system, either that or there is a firewall between 
the front ends and compute nodes. In either case I doubt the NAS sys 
admins are going to reconfigure for me :) So at least for now I'm stuck 
with the two hop ssh tunnels and interactive batch jobs. if there were 
someway to script the ssh tunnel in my batch script I would be golden...

By the way I put the details of the two hop ssh tunnel on the wiki as 
well, and a link to Pat's hpc.mil notes. I don't dare try to summarize 
them since I've never used portfwd and it refuses to compile both on my 
workstation and the cluster.

Hopefully putting these notes on the Wiki will save future ParaView 
users some time and headaches.

Sean Ziegeler wrote:
> Not quite- the pvsc calls ssh with both the tunnel options and the 
> commands to submit the batch job.  You don't even need a pvsc; it just 
> makes the interface fancier.  As long as you or PV executes something 
> like this from your machine:
> ssh -R XXXX:localhost:YYYY remote_machine submit_my_job.sh
>
> This means that port XXXX on remote_machine will be the port to which 
> the server must connect.  Port YYYY (e.g., 11111) on your client 
> machine is the one on which PV listens.  You'd have to tell the server 
> (in the batch submission script, for example) the name of the node and 
> port XXXX to which to connect.
>
> One caveat that might be causing you problems, port forwarding (and 
> "gateway ports" if the server is running on a different node than the 
> login node) must be enabled in the remote_machine's sshd_config.  If 
> not, no ssh tunnels will work at all (see: man ssh and man 
> sshd_config).  That's something that an administrator would need to 
> set up for you.
>
> On 02/08/10 12:26, burlen wrote:
>> So to be sure about what you're saying: Your .pvsc script ssh's to the
>> front end and submits a batch job which when it's scheduled , your batch
>> script creates a -R style tunnel and starts pvserver using PV reverse
>> connection. ? or are you using portfwd or a second ssh session to
>> establish the tunnel ?
>>
>> If you're doing this all from your .pvsc script without a second ssh
>> session and/or portfwd that's awesome! I haven't been able to script
>> this, something about the batch system prevents the tunnel created
>> within the batch job's ssh session from working. I don't know if that's
>> particular to this system or a general fact of life about batch systems.
>>
>> Question: How are you creating the tunnel in your batch script?
>>
>> Sean Ziegeler wrote:
>>> Both ways will work for me in most cases, i.e. a "forward" connection
>>> with ssh -L or a reverse connection with ssh -R.
>>>
>>> However, I find that the reverse method is more scriptable. You can
>>> set up a .pvsc file that the client can load and will call ssh with
>>> the appropriate options and commands for the remote host, all from the
>>> GUI. The client will simply wait for the reverse connection from the
>>> server, whether it takes 5 seconds or 5 hours for the server to get
>>> through the batch queue.
>>>
>>> Using the forward connection method, if the server isn't started soon
>>> enough, the client will attempt to connect and then fail. I've always
>>> had to log in separately, wait for the server to start running, then
>>> tell my client to connect.
>>>
>>> -Sean
>>>
>>> On 02/06/10 12:58, burlen wrote:
>>>> Hi Pat,
>>>>
>>>> My bad. I was looking at the PV wiki, and thought you were talking 
>>>> about
>>>> doing this without an ssh tunnel and using only port forward and
>>>> paraview's --reverse-connection option . Now that I am reading your
>>>> hpc.mil post I see what you mean :)
>>>>
>>>> Burlen
>>>>
>>>>
>>>> pat marion wrote:
>>>>> Maybe I'm misunderstanding what you mean by local firewall, but
>>>>> usually as long as you can ssh from your workstation to the login 
>>>>> node
>>>>> you can use a reverse ssh tunnel.
>>>>
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