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

[Thomas Sattler]

Am 03.08.2012 17:52, schrieb Ole Tange:
>> How about the "Control" feature of (open-)ssh?
> 
> ControlPersist does not exist in my version of ssh.

OK, I checked: It's in my Gentoo (openssh-5.9_p1-r4)
but it's not in Debian Squeeze (openssh-5.5p1-6).

> Can you test if ControlPersist works for this:
> 
>     seq 100 | parallel -j0 ssh server 'echo {};sleep 2'

I have almost no problems. ('parallel' is to fast, and
the control channel needs some time to be initialized)
So I get several

"ControlSocket already exists, disabling multiplexing"

But in case the control channel has been established
in advance, there are no error messages. So I think
the following should work:

let parallel
 - run one "extra" ssh to the target host
 - give it time to establish its connections
 - run all regular ssh's through this
 - close the "extra" ssh when done

This should work on all systems that have the "basic"
ControlMaster feature.

Thomas