On 12/31/2015 04:40 PM, Zhang Chen wrote: > > > On 12/31/2015 10:36 AM, Jason Wang wrote: >> >> On 12/22/2015 06:42 PM, Zhang Chen wrote: >>> From: zhangchen <zhangchen.f...@cn.fujitsu.com> >>> >>> 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. >> Thanks for the work. I don't object this method but still not convinced >> that qemu is the best place for this. >> >> As been raised in the past discussion, it's almost impossible to >> cooperate with vhost backends. If we want this to be used in production >> environment, need to think of a solution for vhost. There's no such >> worry if we decouple this from qemu. >> >>> You can also get the series from: >>> >>> https://github.com/zhangckid/qemu/tree/colo-v2.2-periodic-mode-with-colo-proxyV2 >>> >>> >>> Usage: >>> >>> primary: >>> -netdev tap,id=bn0 -device e1000,netdev=bn0 >>> -object >>> colo-proxy,id=f0,netdev=bn0,queue=all,mode=primary,addr=host:port >>> >>> secondary: >>> -netdev tap,id=bn0 -device e1000,netdev=bn0 >>> -object >>> colo-proxy,id=f0,netdev=bn0,queue=all,mode=secondary,addr=host:port >> Have a quick glance at how secondary mode work. What it does is just >> forwarding packets between a nic and a socket, qemu socket backend did >> exact the same job. You could even use socket in primary node and let >> packet compare module talk to both primary and secondary node. > > If we use qemu socket backend , the same netdev will used by qemu > socket and > qemu netfilter. this will against qemu net design. and then, when colo > do failover, > secondary do not have backend to use. that's the real problem.
Then, maybe it's time to implement changing the netdev of a nic. The point here is that what secondary mode did is in fact a netdev backend instead of a filter ... > > > Thanks > zhangchen > >>> NOTE: >>> queue must set "all". See enum NetFilterDirection for detail. >>> colo-proxy need queue all packets >>> colo-proxy V2 just can compare ip packet >>> >>> >>> ## 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. >>> >>> V2: >>> rebase colo-proxy with qemu-colo-v2.2-periodic-mode >>> fix dave's comments >>> fix wency's comments >>> fix zhanghailiang's comments >>> >>> v1: >>> initial patch. >>> >>> >>> >>> zhangchen (10): >>> Init colo-proxy object based on netfilter >>> Jhash: add linux kernel jhashtable in qemu >>> Colo-proxy: add colo-proxy framework >>> Colo-proxy: add data structure and jhash func >>> net/colo-proxy: Add colo interface to use proxy >>> net/colo-proxy: add socket used by forward func >>> net/colo-proxy: Add packet enqueue & handle func >>> net/colo-proxy: Handle packet and connection >>> net/colo-proxy: Compare pri pkt to sec pkt >>> net/colo-proxy: Colo-proxy do checkpoint and clear >>> >>> include/qemu/jhash.h | 61 ++++ >>> net/Makefile.objs | 1 + >>> net/colo-proxy.c | 939 >>> +++++++++++++++++++++++++++++++++++++++++++++++++++ >>> net/colo-proxy.h | 24 ++ >>> qemu-options.hx | 6 + >>> trace-events | 8 + >>> vl.c | 3 +- >>> 7 files changed, 1041 insertions(+), 1 deletion(-) >>> create mode 100644 include/qemu/jhash.h >>> create mode 100644 net/colo-proxy.c >>> create mode 100644 net/colo-proxy.h >>> >> >> >> . >> >
