Re: Running >10 jobs in parallel on the same remote machine

[Ole Tange]

On Sat, Aug 4, 2012 at 1:25 PM, Thomas Sattler
<sattler@med.uni-frankfurt.de> wrote:
>> I would like to have people test the idea before I implement
>> it. I need your help with the options:
>>
>>   ssh <<what options here?>> server sleep 10000000 &
>>   sleep 3 # To make sure the above is logged in and set up
>>   seq 1000 | parallel -j0 ssh <<what options here?>> server 'echo {};sleep 2'
>>   kill %1 # Kill the sleeping ssh
:
> It can be tested like this:
>
>  1) in one terminal run:
>
>     ssh -o ControlMaster=yes -o ControlPath=/tmp/foo \
>       server "date; read; last | head"
>
>  2) as soon as you can see the output of 'date' you can
>     run the following in another terminal:
>
>     seq 100 | parallel -j0 ssh -o ControlPath=/tmp/foo \
>       server 'echo {};sleep 2'

No good. I get:

mux_client_request_session: session request failed: Session open refused by peer

I do not loose any jobs, but I do not want GNU Parallel to spew out
that kind of warnings.

> The above works fine on my Gentoo machine. Afterwards I
> tested on Debian Squeeze and it just doesn't work. :-(

So are we reaching the conclusion that Control* will not be a usable
solution? Or do you have other ideas that might fix it?

/Ole