Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-08 Thread Michael R. Hines
On 07/03/2014 11:42 AM, Hongyang Yang wrote: I wonder if there is anyway to coordinate this between COLO, Michael Hines microcheckpointing and the two separate reverse-execution projects that also need to do some similar things. Are there any standard APIs for the heartbeet thing we can

Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-08 Thread Hongyang Yang
Hi Michael, Thank you for paying attention on this. On 07/08/2014 02:06 PM, Michael R. Hines wrote: On 07/03/2014 11:42 AM, Hongyang Yang wrote: I wonder if there is anyway to coordinate this between COLO, Michael Hines microcheckpointing and the two separate reverse-execution projects

RE: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-04 Thread Dong, Eddie
I didn't quite understand a couple of things though, perhaps you can explain: 1) If we ignore the TCP sequence number problem, in an SMP machine don't we get other randomnesses - e.g. which core completes something first, or who wins a lock contention, so the output stream might not

Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-04 Thread Dr. David Alan Gilbert
* Dong, Eddie (eddie.d...@intel.com) wrote: I didn't quite understand a couple of things though, perhaps you can explain: 1) If we ignore the TCP sequence number problem, in an SMP machine don't we get other randomnesses - e.g. which core completes something first, or who wins

RE: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-04 Thread Dong, Eddie
Let me clarify on this issue. COLO didn't ignore the TCP sequence number, but uses a new implementation to make the sequence number to be best effort identical between the primary VM (PVM) and secondary VM (SVM). Likely, VMM has to synchronize the emulation of randomization number

Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-04 Thread Andreas Färber
Am 01.07.2014 14:12, schrieb Dr. David Alan Gilbert: Are there any standard APIs for the heartbeet thing we can already tie into? Maybe the http://www.linux-ha.org/wiki/Heartbeat daemon? Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer

Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-04 Thread Dr. David Alan Gilbert
* Dong, Eddie (eddie.d...@intel.com) wrote: Let me clarify on this issue. COLO didn't ignore the TCP sequence number, but uses a new implementation to make the sequence number to be best effort identical between the primary VM (PVM) and secondary VM (SVM). Likely, VMM has to

RE: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-04 Thread Dong, Eddie
Thanks Dave: Whether the randomness value/branch/code path the PVM and SVM may have, It is only a performance issue. COLO never assumes the PVM and SVM has same internal Machine state. From correctness p.o.v, as if the PVM and SVM generate Identical response, we can view the SVM is

Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-02 Thread Hongyang Yang
Hi David, On 07/01/2014 08:12 PM, Dr. David Alan Gilbert wrote: * Hongyang Yang (yan...@cn.fujitsu.com) wrote: Hi Yang, Background: COLO HA project is a high availability solution. Both primary VM (PVM) and secondary VM (SVM) run in parallel. They receive the same request from client, and

Re: [Qemu-devel] [RFC] COLO HA Project proposal

2014-07-01 Thread Dr. David Alan Gilbert
* Hongyang Yang (yan...@cn.fujitsu.com) wrote: Hi Yang, Background: COLO HA project is a high availability solution. Both primary VM (PVM) and secondary VM (SVM) run in parallel. They receive the same request from client, and generate response in parallel too. If the response packets from