two pc's running in parallel

[cooler23]

Hi,

as a lover of music of Peter Gabriel I know that for his loops he is playing live under the live music, he uses a special custom-made system that runs two sub-systems in parallel. The only reason why he (or his team of technicians) does that is safety. There is always some chance that the computer freezes or something won't go as it should. That is why his two mac's (I should say systems) run in parallel. If anything goes wrong the system will automatically switch to the second pc. And although they had Macs and everything with rather overkill power it actually did happened on tour two or three times that the system had to switch to the backup. Noone noticed, even Peter didn't hear the difference or the switch in his in-ear monitors. So to my question:

Is it possible to have say two laptops running the same project in Ableton and one of them is a spare which comes in immediately (like microseconds) if something goes wrong with the first one? And apart from those two laptops both with the same Ableton Live software - what else do I need in terms of software and hardware?

Thanks

[synnack]

You could send midi or OSC to two destinations from whatever controllers or instruments you use on stage to two different laptops and they should be doing the exact same things.

In the midi example: http://www.motu.com/products/midi/xpressxt_usb

I think the bigger problem is designing a system that would detect the "if something goes wrong". I can imagine a manual failover where an engineer goes "oh shit, computers crashing, and cuts over on a mixer, but no clue how that would work in some automated sense with software that would somehow know the box is eating itself yet still be able to send a message to something to fail it over. I bet it's manual and it's a guy making that call.

[cooler23]

Well, from what I remember there was a hidden track in the mix. Noone could hear it but the system was designed to "hear" that signal (just a normal continous sinewave). If there was even a microgap in that signal (which is in other words a "message" that something might go wrong), the system switched immediately to the next computer. But I can't find the source video or any other page. Sorry for that. Thats why I ask here...

[Muzik 4 Machines]

IIRC, there is a special switcher used (cirque du soleil used live for love too)
the device has inputs for all outs of both computers and outputs in the mixer, if one system goes down, the device automagically switch from cpu 1 to cpu2 (probably with a hidden track)

[synnack]

Well, from what I remember there was a hidden track in the mix. Noone could hear it but the system was designed to "hear" that signal (just a normal continous sinewave). If there was even a microgap in that signal (which is in other words a "message" that something might go wrong), the system switched immediately to the next computer. But I can't find the source video or any other page. Sorry for that. Thats why I ask here...

Interesting. If it was a hidden track playing any constant tone you could detect the need to failover with just a measurement of the hidden track amplitude on machine 2 in a max for live device. You'd just need to automate the crossfade between the machines in some way.

[Muzik 4 Machines]

nevermind

but cirque du soleil and peter gabriel use that system i was talking about live to switch from the main to the backup machine

[cooler23]

nevermind

but cirque du soleil and peter gabriel use that system i was talking about live to switch from the main to the backup machine

And do you happened to know what the name of the system was? Any website or video about that? Thanks

[Muzik 4 Machines]

cant find it

[cooler23]

After a search I did about the Cirque du Soleil I've found info about the LCS which is now under Meyer sound. I wrote them and here is what they replied:

"There is a device made by US Audio that does exactly what you are trying to do. We use this device with our Galileo processors to A/B switch outputs, but it was originally designed to switch playback sources. Here you will find a .pdf about this device:

http://whirlwindusa.com/catalog/black-b ... e-switcher

http://whirlwindusa.com/media/uploads/d ... manual.pdf "

[synnack]

Nice! Thanks cooler23.

[ark]

Here's another one: http://radialeng.com/r2011/sw8.php

[3dot...]

it's called "audio engine redundancy"
and is built-in in some heavy-duty (live sound) hardware..
like this one.
http://www.digico.biz/docs2/products/SD7T.shtml

basically.. it's an exact copy of the audio engine running in parallel...
responding to the same controls.
of course.. there is no clock/sync..
both mirror each others' behavior and the 2nd kicks in less than a sec. after the 1st dies..
it's almost instant and unnoticeable..

the case with Live is that 2 playing sequencers need to be in sync.
which is probably doable

how much $$ you have?
cuz PG's got some dough..

[3dot...]

internally basically it's 2 computers running which know each-others' state.. and can mirror it.
and an algo that knows to switch between the 2 in realtime in case of hardware/software failure..
you could even switch between the 2 engines seamlessly during the show.. no one should notice..

[Muzik 4 Machines]

in an ableton live scenario, how would one go to have say the APC40 be the remothe for both so if there is a switchover, the 2 sessions are at the same place controller wise?

[3dot...]

in an ableton live scenario, how would one go to have say the APC40 be the remothe for both so if there is a switchover, the 2 sessions are at the same place controller wise?

yep..
but I don't know that he could do that...
he'd need to mirror the APC40 to the 2nd computer somehow..
but then.. what happens when the 1st computer fails..
does he physically connect the APC to the 2nd computer?
or does he have a spare APC connected to the 2nd while receiving control from the 1st?

btw in an (big) live show scenario..
you have 2 engines for FOH
2 for monitoring
and 2 for audio playback (I'm guessing)..