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

[Shao Zhang]

Does rsh have the same limitations?  Is it viable?

On Fri, Aug 3, 2012 at 8:52 AM, Ole Tange <tange@gnu.org> wrote:
> On Fri, Aug 3, 2012 at 4:26 PM, Thomas Sattler
> <sattler@med.uni-frankfurt.de> wrote:
>> May I suggest a different solution for the problem?
>> How about the "Control" feature of (open-)ssh?
>
> ControlPersist does not exist in my version of ssh. It is probably a
> new option, and I am not too fond of depending on new versions.
>
> Multiplexing using ControlMaster already exists (-M), but seems not to
> fix the issue.
>
> Can you test if ControlPersist works for this:
>
>     seq 100 | parallel -j0 ssh server 'echo {};sleep 2'
>
> Preferably you should not get:
>
>     channel 21: open failed: administratively prohibited: open failed
>     mux_client_request_session: session request failed: Session open
> refused by peer
>     ControlSocket ... already exists, disabling multiplexing
>
> What I am proposing is something similar to:
>
>     (seq 0.01 0.02 2; echo 0) | parallel -j0 'sleep {};ssh server echo
> {};sleep 2'
>
> (assuming it takes 0.1 second to login)
>
>
> /Ole
>