Re: [Qemu-devel] [RFC PATCH 0/9] Add colo-proxy based on netfilter

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

Hi,Dave

On 12/02/2015 12:44 AM, Dr. David Alan Gilbert wrote:
> * Zhang Chen (zhangchen.fnst@cn.fujitsu.com) wrote:
>> Hi,all
>>
>> This patch add an colo-proxy object, COLO-Proxy is a part of COLO,
>> based on qemu netfilter and it's a plugin for qemu netfilter. the function
>> keep Secondary VM connect normal to Primary VM and compare packets
>> sent by PVM to sent by SVM.if the packet difference,notify COLO do
>> checkpoint and send all primary packet has queued.
>>
>> You can also get the series from:
>>
>> https://github.com/zhangckid/qemu/tree/colo-proxy-V1
>>
>> Usage:
>>
>> primary:
>> -netdev tap,id=bn0 -device e1000,netdev=bn0
>> -object colo-proxy,id=f0,netdev=bn0,queue=all,mode=primary,addr=ip:port
>>
>> secondary:
>> -netdev tap,id=bn0 -device e1000,netdev=bn0
>> -object colo-proxy,id=f0,netdev=bn0,queue=all,mode=secondary,addr=ip:port
> If we have more than one NIC on the guest, do you intend to allow
> multiple colo-proxy's ?

Yes,we support.Colo-proxy based on netfilter, same to filter-buffer, 
proxy attach your netdev.
but we haven't test it

> Having read through the series, it looks like the main missing piece
> is the work to synchronise sequence numbers.

Yes, we will support it in the futrue

> I think also you'll need to clean out the connection hash when either
> you see both sides have closed the connection or (maybe after some
> time of idleness as well? Otherwise we'd just accumulate dead connections
> overtime).
>
> I'm guessing the buffer filter also has to be created on the command line?
> How does the order of buffers work?
>
> Dave

In colo-proxy we have done buffer filter's work,so we just need startup
colo-proxy.

Thanks for review
zhangchen

>> NOTE:
>> queue must set "all". See enum NetFilterDirection for detail.
>> colo-proxy need queue all packets
>> colo-proxy V1 just a demo of colo proxy,not pass test with colo upstream
>>
>>
>> ## Background
>>
>> COLO FT/HA (COarse-grain LOck-stepping Virtual Machines for Non-stop Service)
>> 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
>> responses in parallel too. If the response packets from PVM and SVM are
>> identical, they are released immediately. Otherwise, a VM checkpoint (on
>> demand)is conducted.
>>
>> Paper:
>> http://www.socc2013.org/home/program/a3-dong.pdf?attredirects=0
>>
>> COLO on Xen:
>> http://wiki.xen.org/wiki/COLO_-_Coarse_Grain_Lock_Stepping
>>
>> COLO on Qemu/KVM:
>> http://wiki.qemu.org/Features/COLO
>>
>> By the needs of capturing response packets from PVM and SVM and finding out
>> whether they are identical, we introduce a new module to qemu networking
>> called colo-proxy.
>>
>>
>> v1:
>>   initial patch.
>>
>>
>>
>> zhangchen (9):
>>    Init colo-proxy object based on netfilter
>>    jhash: add linux kernel jhashtable in qemu
>>    colo-proxy: add colo-proxy framework
>>    colo-proxy: add colo-proxy setup work
>>    net/colo-proxy: add colo packet handler
>>    net/colo-proxy: add packet forward function
>>    net/colo-proxy: add packet enqueue and handle function
>>    net/colo-proxy: enqueue primary and secondary packet
>>    net/colo-proxy: add packet compare and notify checkpoint
>>
>>   include/qemu/jhash.h |  52 ++++
>>   net/Makefile.objs    |   1 +
>>   net/colo-proxy.c     | 745 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>   net/colo-proxy.h     | 124 +++++++++
>>   qemu-options.hx      |   4 +
>>   vl.c                 |   3 +-
>>   6 files changed, 928 insertions(+), 1 deletion(-)
>>   create mode 100644 include/qemu/jhash.h
>>   create mode 100644 net/colo-proxy.c
>>   create mode 100644 net/colo-proxy.h
>>
>> -- 
>> 1.9.1
>>
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
>
> .
>