Re: [Qemu-devel] 答复: Re: 答复: Re: [BUG]COLO failover hang

[Hailiang Zhang]

Hi,

On 2017/3/21 16:10, address@hidden wrote:
> Thank you。
>
> I have test aready。
>
> When the Primary Node panic,the Secondary Node qemu hang at the same place。
>
> Incorrding http://wiki.qemu-project.org/Features/COLO ，kill Primary Node qemu 
> will not produce the problem,but Primary Node panic can。
>
> I think due to the feature of channel does not support 
> QIO_CHANNEL_FEATURE_SHUTDOWN.

Yes, you are right, when we do failover for primary/secondary VM, we will 
shutdown the related
fd in case it is stuck in the read/write fd.

It seems that you didn't follow the above introduction exactly to do the test. 
Could you
share your test procedures ? Especially the commands used in the test.

Thanks,
Hailiang

> when failover,channel_shutdown could not shut down the channel.
>
>
> so the colo_process_incoming_thread will hang at recvmsg.
>
>
> I test a patch:
>
>
> diff --git a/migration/socket.c b/migration/socket.c
>
>
> index 13966f1..d65a0ea 100644
>
>
> --- a/migration/socket.c
>
>
> +++ b/migration/socket.c
>
>
> @@ -147,8 +147,9 @@ static gboolean socket_accept_incoming_migration(QIOChannel 
> *ioc,
>
>
>       }
>
>
>
>
>
>       trace_migration_socket_incoming_accepted()
>
>
>
>
>
>       qio_channel_set_name(QIO_CHANNEL(sioc), "migration-socket-incoming")
>
>
> +    qio_channel_set_feature(QIO_CHANNEL(sioc), QIO_CHANNEL_FEATURE_SHUTDOWN)
>
>
>       migration_channel_process_incoming(migrate_get_current(),
>
>
>                                          QIO_CHANNEL(sioc))
>
>
>       object_unref(OBJECT(sioc))
>
>
>
>
> My test will not hang any more.
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> 原始邮件
>
>
>
> 发件人： address@hidden
> 收件人：王广10165992 address@hidden
> 抄送人： address@hidden address@hidden
> 日 期 ：2017年03月21日 15:58
> 主 题 ：Re: [Qemu-devel]  答复: Re:  [BUG]COLO failover hang
>
>
>
>
>
> Hi,Wang.
>
> You can test this branch:
>
> https://github.com/coloft/qemu/tree/colo-v5.1-developing-COLO-frame-v21-with-shared-disk
>
> and please follow wiki ensure your own configuration correctly.
>
> http://wiki.qemu-project.org/Features/COLO
>
>
> Thanks
>
> Zhang Chen
>
>
> On 03/21/2017 03:27 PM, address@hidden wrote:
> ＞
> ＞ hi.
> ＞
> ＞ I test the git qemu master have the same problem.
> ＞
> ＞ (gdb) bt
> ＞
> ＞ #0  qio_channel_socket_readv (ioc=0x7f65911b4e50, iov=0x7f64ef3fd880,
> ＞ niov=1, fds=0x0, nfds=0x0, errp=0x0) at io/channel-socket.c:461
> ＞
> ＞ #1  0x00007f658e4aa0c2 in qio_channel_read
> ＞ (address@hidden, address@hidden "",
> ＞ address@hidden, address@hidden) at io/channel.c:114
> ＞
> ＞ #2  0x00007f658e3ea990 in channel_get_buffer (opaque=＜optimized out＞,
> ＞ buf=0x7f65907cb838 "", pos=＜optimized out＞, size=32768) at
> ＞ migration/qemu-file-channel.c:78
> ＞
> ＞ #3  0x00007f658e3e97fc in qemu_fill_buffer (f=0x7f65907cb800) at
> ＞ migration/qemu-file.c:295
> ＞
> ＞ #4  0x00007f658e3ea2e1 in qemu_peek_byte (address@hidden,
> ＞ address@hidden) at migration/qemu-file.c:555
> ＞
> ＞ #5  0x00007f658e3ea34b in qemu_get_byte (address@hidden) at
> ＞ migration/qemu-file.c:568
> ＞
> ＞ #6  0x00007f658e3ea552 in qemu_get_be32 (address@hidden) at
> ＞ migration/qemu-file.c:648
> ＞
> ＞ #7  0x00007f658e3e66e5 in colo_receive_message (f=0x7f65907cb800,
> ＞ address@hidden) at migration/colo.c:244
> ＞
> ＞ #8  0x00007f658e3e681e in colo_receive_check_message (f=＜optimized
> ＞ out＞, address@hidden,
> ＞ address@hidden)
> ＞
> ＞     at migration/colo.c:264
> ＞
> ＞ #9  0x00007f658e3e740e in colo_process_incoming_thread
> ＞ (opaque=0x7f658eb30360 ＜mis_current.31286＞) at migration/colo.c:577
> ＞
> ＞ #10 0x00007f658be09df3 in start_thread () from /lib64/libpthread.so.0
> ＞
> ＞ #11 0x00007f65881983ed in clone () from /lib64/libc.so.6
> ＞
> ＞ (gdb) p ioc-＞name
> ＞
> ＞ $2 = 0x7f658ff7d5c0 "migration-socket-incoming"
> ＞
> ＞ (gdb) p ioc-＞features        Do not support QIO_CHANNEL_FEATURE_SHUTDOWN
> ＞
> ＞ $3 = 0
> ＞
> ＞
> ＞ (gdb) bt
> ＞
> ＞ #0  socket_accept_incoming_migration (ioc=0x7fdcceeafa90,
> ＞ condition=G_IO_IN, opaque=0x7fdcceeafa90) at migration/socket.c:137
> ＞
> ＞ #1  0x00007fdcc6966350 in g_main_dispatch (context=＜optimized out＞) at
> ＞ gmain.c:3054
> ＞
> ＞ #2  g_main_context_dispatch (context=＜optimized out＞,
> ＞ address@hidden) at gmain.c:3630
> ＞
> ＞ #3  0x00007fdccb8a6dcc in glib_pollfds_poll () at util/main-loop.c:213
> ＞
> ＞ #4  os_host_main_loop_wait (timeout=＜optimized out＞) at
> ＞ util/main-loop.c:258
> ＞
> ＞ #5  main_loop_wait (address@hidden) at
> ＞ util/main-loop.c:506
> ＞
> ＞ #6  0x00007fdccb526187 in main_loop () at vl.c:1898
> ＞
> ＞ #7  main (argc=＜optimized out＞, argv=＜optimized out＞, envp=＜optimized
> ＞ out＞) at vl.c:4709
> ＞
> ＞ (gdb) p ioc-＞features
> ＞
> ＞ $1 = 6
> ＞
> ＞ (gdb) p ioc-＞name
> ＞
> ＞ $2 = 0x7fdcce1b1ab0 "migration-socket-listener"
> ＞
> ＞
> ＞ May be socket_accept_incoming_migration should
> ＞ call qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN)??
> ＞
> ＞
> ＞ thank you.
> ＞
> ＞
> ＞
> ＞
> ＞
> ＞ 原始邮件
> ＞ address@hidden
> ＞ address@hidden
> ＞ address@hidden@huawei.com＞
> ＞ *日 期 ：*2017年03月16日 14:46
> ＞ *主 题 ：**Re: [Qemu-devel] COLO failover hang*
> ＞
> ＞
> ＞
> ＞
> ＞ On 03/15/2017 05:06 PM, wangguang wrote:
> ＞ ＞   am testing QEMU COLO feature described here [QEMU
> ＞ ＞ Wiki](http://wiki.qemu-project.org/Features/COLO).
> ＞ ＞
> ＞ ＞ When the Primary Node panic,the Secondary Node qemu hang.
> ＞ ＞ hang at recvmsg in qio_channel_socket_readv.
> ＞ ＞ And  I run  { 'execute': 'nbd-server-stop' } and { "execute":
> ＞ ＞ "x-colo-lost-heartbeat" } in Secondary VM's
> ＞ ＞ monitor,the  Secondary Node qemu still hang at recvmsg .
> ＞ ＞
> ＞ ＞ I found that the colo in qemu is not complete yet.
> ＞ ＞ Do the colo have any plan for development?
> ＞
> ＞ Yes, We are developing. You can see some of patch we pushing.
> ＞
> ＞ ＞ Has anyone ever run it successfully? Any help is appreciated!
> ＞
> ＞ In our internal version can run it successfully,
> ＞ The failover detail you can ask Zhanghailiang for help.
> ＞ Next time if you have some question about COLO,
> ＞ please cc me and zhanghailiang address@hidden
> ＞
> ＞
> ＞ Thanks
> ＞ Zhang Chen
> ＞
> ＞
> ＞ ＞
> ＞ ＞
> ＞ ＞
> ＞ ＞ centos7.2+qemu2.7.50
> ＞ ＞ (gdb) bt
> ＞ ＞ #0  0x00007f3e00cc86ad in recvmsg () from /lib64/libpthread.so.0
> ＞ ＞ #1  0x00007f3e0332b738 in qio_channel_socket_readv (ioc=＜optimized out＞,
> ＞ ＞ iov=＜optimized out＞, niov=＜optimized out＞, fds=0x0, nfds=0x0, errp=0x0) at
> ＞ ＞ io/channel-socket.c:497
> ＞ ＞ #2  0x00007f3e03329472 in qio_channel_read (address@hidden,
> ＞ ＞ address@hidden "", address@hidden,
> ＞ ＞ address@hidden) at io/channel.c:97
> ＞ ＞ #3  0x00007f3e032750e0 in channel_get_buffer (opaque=＜optimized out＞,
> ＞ ＞ buf=0x7f3e05910f38 "", pos=＜optimized out＞, size=32768) at
> ＞ ＞ migration/qemu-file-channel.c:78
> ＞ ＞ #4  0x00007f3e0327412c in qemu_fill_buffer (f=0x7f3e05910f00) at
> ＞ ＞ migration/qemu-file.c:257
> ＞ ＞ #5  0x00007f3e03274a41 in qemu_peek_byte (address@hidden,
> ＞ ＞ address@hidden) at migration/qemu-file.c:510
> ＞ ＞ #6  0x00007f3e03274aab in qemu_get_byte (address@hidden) at
> ＞ ＞ migration/qemu-file.c:523
> ＞ ＞ #7  0x00007f3e03274cb2 in qemu_get_be32 (address@hidden) at
> ＞ ＞ migration/qemu-file.c:603
> ＞ ＞ #8  0x00007f3e03271735 in colo_receive_message (f=0x7f3e05910f00,
> ＞ ＞ address@hidden) at migration/colo.c:215
> ＞ ＞ #9  0x00007f3e0327250d in colo_wait_handle_message (errp=0x7f3d62bfaa48,
> ＞ ＞ checkpoint_request=＜synthetic pointer＞, f=＜optimized out＞) at
> ＞ ＞ migration/colo.c:546
> ＞ ＞ #10 colo_process_incoming_thread (opaque=0x7f3e067245e0) at
> ＞ ＞ migration/colo.c:649
> ＞ ＞ #11 0x00007f3e00cc1df3 in start_thread () from /lib64/libpthread.so.0
> ＞ ＞ #12 0x00007f3dfc9c03ed in clone () from /lib64/libc.so.6
> ＞ ＞
> ＞ ＞
> ＞ ＞
> ＞ ＞
> ＞ ＞
> ＞ ＞ --
> ＞ ＞ View this message in context: 
> http://qemu.11.n7.nabble.com/COLO-failover-hang-tp473250.html
> ＞ ＞ Sent from the Developer mailing list archive at Nabble.com.
> ＞ ＞
> ＞ ＞
> ＞ ＞
> ＞ ＞
> ＞
> ＞ --
> ＞ Thanks
> ＞ Zhang Chen
> ＞
> ＞
> ＞
> ＞
> ＞