[sheepdog] [sheepdog-users] plan for Sheepdog 1.0 and new organization

[MORITA Kazutaka]

At Thu, 23 May 2013 19:10:38 +0800,
Liu Yuan wrote:
> 
> On 05/23/2013 07:03 PM, MORITA Kazutaka wrote:
> > I think of improving the current recovery codes in near future so that
> > the recovery thread doesn't affect VM I/O as far as it can.
> 
> It looks to me very hard, at least very hard to implement transparently.
> Many targets contradict themselves, to name a few:
> 
>  1 'force recovery' after cluster crash will want the full speed
>  2 VM don't want recovery take its IO channel but want it to be get done
> as soon as possible
>  3 People want to check run as fast as possible but don't want it to
> interfere with VM.

What I came up with were:

 - Make the current recovery process multi-threaded.  Then sheep can
   do multi-thread I/O against unrecovered objects, too.

 - Sleep a bit (e.g. 100 ms) before recovering a object while there
   are outstanding I/Os from VMs.

 - Use event_loop_prio() and add higher priority for I/Os from VMs.

I'm not sure these work well, but I think they are worth a try.

Thanks,

Kazutaka