From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56175) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YUnWx-0004t2-Ma for qemu-devel@nongnu.org; Sun, 08 Mar 2015 22:34:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YUnWu-0003f4-Fi for qemu-devel@nongnu.org; Sun, 08 Mar 2015 22:34:55 -0400 Received: from [59.151.112.132] (port=12901 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YUnWc-0003bw-V6 for qemu-devel@nongnu.org; Sun, 08 Mar 2015 22:34:52 -0400 Message-ID: <54FD074C.5060009@cn.fujitsu.com> Date: Mon, 9 Mar 2015 10:37:00 +0800 From: Wen Congyang MIME-Version: 1.0 References: <1425562294-1616-1-git-send-email-dgilbert@redhat.com> <54F9077B.3020803@huawei.com> <20150306183021.GE2507@work-vm> In-Reply-To: <20150306183021.GE2507@work-vm> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC 0/1] Rolling stats on colo List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" , zhanghailiang Cc: hangaohuai@huawei.com, yunhong.jiang@intel.com, eddie.dong@intel.com, qemu-devel@nongnu.org, peter.huangpeng@huawei.com, luis@cs.umu.se On 03/07/2015 02:30 AM, Dr. David Alan Gilbert wrote: > * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote: >> On 2015/3/5 21:31, Dr. David Alan Gilbert (git) wrote: >>> From: "Dr. David Alan Gilbert" >> >> Hi Dave, >> >>> >>> Hi, >>> I'm getting COLO running on a couple of our machines here >>> and wanted to see what was actually going on, so I merged >>> in my recent rolling-stats code: >>> >>> http://lists.gnu.org/archive/html/qemu-devel/2015-03/msg00648.html >>> >>> with the following patch, and now I get on the primary side, >>> info migrate shows me: >>> >>> capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off colo: on >>> Migration status: colo >>> total time: 0 milliseconds >>> colo checkpoint (ms): Min/Max: 0, 10000 Mean: -1.1415868e-13 (Weighted: 4.3136025e-158) Count: 4020 Values: 0@1425561742237, 0@1425561742300, 0@1425561742363, 0@1425561742426, 0@1425561742489, 0@1425561742555, 0@1425561742618, 0@1425561742681, 0@1425561742743, 0@1425561742824 >>> colo paused time (ms): Min/Max: 55, 2789 Mean: 63.9 (Weighted: 76.243584) Count: 4019 Values: 62@1425561742237, 62@1425561742300, 62@1425561742363, 62@1425561742426, 61@1425561742489, 65@1425561742555, 62@1425561742618, 62@1425561742681, 61@1425561742743, 80@1425561742824 >>> colo checkpoint size: Min/Max: 18351, 2.1731606e+08 Mean: 150096.4 (Weighted: 127195.56) Count: 4020 Values: 211246@1425561742238, 186622@1425561742301, 227662@1425561742364, 219454@1425561742428, 268702@1425561742490, 96334@1425561742556, 47086@1425561742619, 42982@1425561742682, 55294@1425561742744, 145582@1425561742825 >>> >>> which suggests I've got a problem with the packet comparison; but that's >>> a separate issue I'll look at. >>> >> >> There is an obvious mistake we have made in proxy, the macro 'IPS_UNTRACKED_BIT' in colo-patch-for-kernel.patch should be 14, >> so please fix it before do the follow test. Sorry for this low-grade mistake, we should do full test before issue it. ;) > > No, that's OK; we all make them. > > However, that didn't cure my problem; but after a bit of experimentation I now have > COLO working pretty well; thanks for the help! > > 1) I had to disable IPv6 in the guest; it doesn't look like the > conntrack is coping with IPv6 ICMPV6, and on our test network > we're getting a few 10s of those each second, so it's constant > miscompares (they seem to be neighbour broadcasts and multicast > stuff). > > 2) It looks like virtio-net is sending ARPs - possibly every time > that a snapshot is loaded; it's not the 'qemu' announce-self code, > (I added some debug there and it's not being called); and ARPs > cause a miscompare - so you get a continuous streem of miscompares > because a miscompare triggers a new snapshot, that sends more ARPs. > I solved this by switching to e1000. > > 3) The other problem with virtio is it's occasionally triggering a > 'virtio: error trying to map MMIO memory' from qemu; I'm not sure > why, the state COLO sends over should always be consistent. I don't meet this problem. Can you provide your command line? Primary or secondary qemu reports this error message? > > 4) With the e1000 setup; connections are generally fairly responsive, > but sshing into the guest takes *ages* (10s of seconds). I'm not sure > why, because a curl to a web server seems OK (less than a second) > and once the ssh is open it's pretty responsive. > > 5) I've seen one instance of; > 'qemu-system-x86_64: block/raw-posix.c:836: handle_aiocb_rw: Assertion `p - buf == aiocb->aio_nbytes' failed.' > on the primary side. It is a known bug in quorum. You can try this patch: http://lists.nongnu.org/archive/html/qemu-devel/2015-01/msg04507.html Thanks Wen Congyang > > Stats for a mostly idle guest are now showing: > > colo checkpoint (ms): Min/Max: 0, 10004 Mean: 1592.1 (Weighted: 1806.214) Count: 227 Values: 1650@1425666160229, 1661@1425666161998, 1662@1425666163736, 1687@1425666165524, 811@1425666166438, 788@1425666167298, 1619@1425666168992, 1699@1425666170793, 2711@1425666173602, 1633@1425666175315 > colo paused time (ms): Min/Max: 58, 2975 Mean: 90.3 (Weighted: 94.109752) Count: 227 Values: 107@1425666160337, 75@1425666162074, 100@1425666163837, 102@1425666165627, 71@1425666166510, 74@1425666167373, 101@1425666169094, 97@1425666170891, 79@1425666173682, 97@1425666175413 > colo checkpoint size: Min/Max: 212252, 1.9241972e+08 Mean: 5569622.6 (Weighted: 4826386.5) Count: 227 Values: 5998892@1425666160230, 4660988@1425666161999, 6002996@1425666163737, 5945540@1425666165525, 4833356@1425666166439, 5510606@1425666167299, 5793692@1425666168993, 5584388@1425666170794, 7016684@1425666173603, 4349084@1425666175316 > > So, one checkpoint every ~1.5 seconds; that's just with an > ssh connected and a script doing a 'curl' to it's http > repeatedly. Running 'top' on the ssh with a fast refresh > brings the checkpoints much faster; I guess that's because > the output of top is quite random. > >> To be honest, the proxy part in github is not integrated, we have cut it just for easy review and understand, so there may be some mistakes. > > Yes, that's OK; and I've had a few kernel crashes; normally > when the qemu crashes, the kernel doesn't really like it; > but that's OK, I'm sure it will get better. > > I added the following to make my debug easier; which is how > I found the IPv6 problem. > > diff --git a/xt_PMYCOLO.c b/xt_PMYCOLO.c > index 9e50b62..13c0b48 100644 > --- a/xt_PMYCOLO.c > +++ b/xt_PMYCOLO.c > @@ -1072,7 +1072,7 @@ resolve_master_ct(struct sk_buff *skb, unsigned int dataoff, > h = nf_conntrack_find_get(&init_net, NF_CT_DEFAULT_ZONE, &tuple); > > if (h == NULL) { > - pr_dbg("can't find master's ct for slaver packet\n"); > + pr_dbg("can't find master's ct for slaver packet (pf/l3num=%d protonum=%d)\n", l3num, protonum); > return NULL; > } > > @@ -1092,7 +1092,7 @@ nf_conntrack_slaver_in(u_int8_t pf, unsigned int hooknum, > /* rcu_read_lock()ed by nf_hook_slow */ > l3proto = __nf_ct_l3proto_find(pf); > if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff, &protonum) <= 0) { > - pr_dbg("slaver: l3proto not prepared to track yet or error occurred\n"); > + pr_dbg("slaver: l3proto not prepared to track yet or error occurred (pf=%d)\n", pf); > NF_CT_STAT_INC_ATOMIC(&init_net, error); > NF_CT_STAT_INC_ATOMIC(&init_net, invalid); > goto out; > >> >> Thanks, >> zhanghailiang > > Thanks, > > Dave >> >> >>> Dave >>> >>> Dr. David Alan Gilbert (1): >>> COLO: Add primary side rolling statistics >>> >>> hmp.c | 12 ++++++++++++ >>> include/migration/migration.h | 3 +++ >>> migration/colo.c | 15 +++++++++++++++ >>> migration/migration.c | 30 ++++++++++++++++++++++++++++++ >>> qapi-schema.json | 11 ++++++++++- >>> 5 files changed, 70 insertions(+), 1 deletion(-) >>> >> >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > . >