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References: <20160122193534.GF2482@work-vm> <56A57B43.1040103@cn.fujitsu.com>
From: Li Zhijian <lizhijian@cn.fujitsu.com>
Message-ID: <56A58441.4030704@cn.fujitsu.com>
Date: Mon, 25 Jan 2016 10:11:13 +0800
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Subject: Re: [Qemu-devel] COLO: how to flip a secondary to a primary?
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To: Wen Congyang <wency@cn.fujitsu.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Changlong Xie <xiecl.fnst@cn.fujitsu.com>, zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Simon Kollberg <dv11skg@cs.umu.se>, Luis Tomas <luis@cs.umu.se>, qemu devel <qemu-devel@nongnu.org>, qemu block <qemu-block@nongnu.org>, Abel Souza <abel@cs.umu.se>



On 01/25/2016 09:32 AM, Wen Congyang wrote:
>> >    f) I've not thought about the colo-proxy that much yet - I guess that
>> >       existing connections need to keep their sequence number offset but

Strictly speaking， after failover, we only need to keep servicing for the tcp connections which are
established after the last checkpoint but not all existing connections. Because after a checkpoint
（primary and secondary node works well）, primary vm and secondary vm is same， that means the existing
tcp connection has the same sequence。

>> >       new connections made by what is now the primary dont need to do anything
>> >       special.
Yes, you are right.


> Hailiang or Zhijian can answer this question.


Thanks
Li Zhijian