[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [POC] colo-proxy in qemu
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [POC] colo-proxy in qemu |
Date: |
Thu, 30 Jul 2015 09:03:40 +0100 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
* Dong, Eddie (address@hidden) wrote:
> > >
> > > A question here, the packet comparing may be very tricky. For example,
> > > some protocol use random data to generate unpredictable id or
> > > something else. One example is ipv6_select_ident() in Linux. So COLO
> > > needs a mechanism to make sure PVM and SVM can generate same random
> > data?
> > >
> > Good question, the random data connection is a big problem for COLO. At
> > present, it will trigger checkpoint processing because of the different
> > random
> > data.
> > I don't think any mechanisms can assure two different machines generate the
> > same random data. If you have any ideas, pls tell us :)
> >
> > Frequent checkpoint can handle this scenario, but maybe will cause the
> > performance poor. :(
> >
> The assumption is that, after VM checkpoint, SVM and PVM have identical
> internal state, so the pattern used to generate random data has high
> possibility to generate identical data at short time, at least...
They do diverge pretty quickly though; I have simple examples which
reliably cause a checkpoint because of simple randomness in applications.
Dave
> Thx Eddie
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
Re: [Qemu-devel] [POC] colo-proxy in qemu, Dong, Eddie, 2015/07/23
Re: [Qemu-devel] [POC] colo-proxy in qemu, Jason Wang, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Gonglei, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Dong, Eddie, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu,
Dr. David Alan Gilbert <=
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Jason Wang, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Dr. David Alan Gilbert, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Gonglei, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Dr. David Alan Gilbert, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, zhanghailiang, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Dr. David Alan Gilbert, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Yang Hongyang, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Dr. David Alan Gilbert, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, Yang Hongyang, 2015/07/30
- Re: [Qemu-devel] [POC] colo-proxy in qemu, zhanghailiang, 2015/07/30