6:49 p.m.
I'm trying to debug a new virsh command, and had two terminals up, one
running './run gdb tools/virsh' (I originally ran virsh directly, but
re-ran under gdb to get a trace) and the other running './run gdb
daemon/libvirtd'. Because I forgot to use the -k0 argument to disable
keepalives, and took too long while at a breakpoint on the libvirtd
terminal, my virsh session tried to report a keepalive failure:
[New Thread 0x7fffe7b8c700 (LWP 7143)]
2014-05-20 23:40:22.337+0000: 7138: info : libvirt version: 1.2.5
2014-05-20 23:40:22.337+0000: 7138: warning :
virKeepAliveTimerInternal:143 : No response from client 0x55555586a520
after 6 keepalive messages in 35 seconds
2014-05-20 23:40:22.337+0000: 7143: warning :
virKeepAliveTimerInternal:143 : No response from client 0x55555586a520
after 6 keepalive messages in 35 seconds
error: internal error: received hangup / error event on socket
but then it just hangs there. A backtrace shows that it is hanging
trying to reconnect:
(gdb) bt
#0 0x00007ffff39129dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1 0x00007ffff798e3c1 in virNetClientIOEventLoop (client=0x55555586ae10,
thiscall=0x55555586b090) at rpc/virnetclient.c:1514
#2 0x00007ffff798ecbf in virNetClientIO (client=0x55555586ae10,
thiscall=0x55555586b090) at rpc/virnetclient.c:1786
#3 0x00007ffff798f5ab in virNetClientSendInternal (client=0x55555586ae10,
msg=0x55555586ada0, expectReply=true, nonBlock=false)
at rpc/virnetclient.c:1958
#4 0x00007ffff798f648 in virNetClientSendWithReply (client=0x55555586ae10,
msg=0x55555586ada0) at rpc/virnetclient.c:1986
#5 0x00007ffff7990580 in virNetClientProgramCall (prog=0x55555586afd0,
client=0x55555586ae10, serial=0, proc=66, noutfds=0, outfds=0x0,
ninfds=0x0, infds=0x0, args_filter=0x7ffff394f270 <__GI_xdr_void>,
args=0x0, ret_filter=0x7ffff798152c <xdr_remote_auth_list_ret>,
ret=0x7fffffffd6f0) at rpc/virnetclientprogram.c:329
#6 0x00007ffff7975d4c in callFull (conn=0x555555869fb0,
priv=0x55555586ab30,
flags=0, fdin=0x0, fdinlen=0, fdout=0x0, fdoutlen=0x0, proc_nr=66,
args_filter=0x7ffff394f270 <__GI_xdr_void>, args=0x0,
ret_filter=0x7ffff798152c <xdr_remote_auth_list_ret>,
ret=0x7fffffffd6f0 "") at remote/remote_driver.c:6544
#7 0x00007ffff7975e25 in call (conn=0x555555869fb0, priv=0x55555586ab30,
flags=0, proc_nr=66, args_filter=0x7ffff394f270 <__GI_xdr_void>,
args=0x0,
ret_filter=0x7ffff798152c <xdr_remote_auth_list_ret>,
---Type <return> to continue, or q <return> to quit---
ret=0x7fffffffd6f0 "") at remote/remote_driver.c:6566
#8 0x00007ffff795f7f1 in remoteAuthenticate (conn=0x555555869fb0,
priv=0x55555586ab30, auth=0x7ffff7d71520 <virConnectAuthDefault>,
authtype=0x0) at remote/remote_driver.c:3939
#9 0x00007ffff7957f0a in doRemoteOpen (conn=0x555555869fb0,
priv=0x55555586ab30, auth=0x7ffff7d71520 <virConnectAuthDefault>,
flags=0)
at remote/remote_driver.c:973
#10 0x00007ffff795890b in remoteConnectOpen (conn=0x555555869fb0,
auth=0x7ffff7d71520 <virConnectAuthDefault>, flags=0)
at remote/remote_driver.c:1190
#11 0x00007ffff78fc5e5 in do_open (name=0x0,
auth=0x7ffff7d71520 <virConnectAuthDefault>, flags=0) at libvirt.c:1147
#12 0x00007ffff78fd093 in virConnectOpenAuth (name=0x0,
auth=0x7ffff7d71520 <virConnectAuthDefault>, flags=0) at libvirt.c:1390
#13 0x0000555555575a67 in vshConnect (ctl=0x7fffffffdbc0, uri=0x0,
readonly=false) at virsh.c:337
#14 0x0000555555575c23 in vshReconnect (ctl=0x7fffffffdbc0) at virsh.c:383
#15 0x000055555557943a in vshCommandRun (ctl=0x7fffffffdbc0,
cmd=0x5555557f4900) at virsh.c:1853
#16 0x000055555557d8de in main (argc=5, argv=0x7fffffffdda8) at virsh.c:3617
It seems odd that virsh is hanging rather than gracefully exit, because
it is trying too hard to reconnect in spite of being forcefully
disconnected due to a keepalive timeout. But I'm not sure what, if
anything, we could tweak to make this failure mode not require a Ctrl-C
on my end to get rid of the failed virsh. It also reiterates the idea
that we really ought to allow for a user-specified timeout to
virConnect, rather than blocking forever.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
6:29 a.m.
On Tue, May 20, 2014 at 05:49:54PM -0600, Eric Blake wrote:
I'm trying to debug a new virsh command, and had two terminals up,
one
running './run gdb tools/virsh' (I originally ran virsh directly, but
re-ran under gdb to get a trace) and the other running './run gdb
daemon/libvirtd'. Because I forgot to use the -k0 argument to disable
keepalives, and took too long while at a breakpoint on the libvirtd
terminal, my virsh session tried to report a keepalive failure:
[New Thread 0x7fffe7b8c700 (LWP 7143)]
2014-05-20 23:40:22.337+0000: 7138: info : libvirt version: 1.2.5
2014-05-20 23:40:22.337+0000: 7138: warning :
virKeepAliveTimerInternal:143 : No response from client 0x55555586a520
after 6 keepalive messages in 35 seconds
2014-05-20 23:40:22.337+0000: 7143: warning :
virKeepAliveTimerInternal:143 : No response from client 0x55555586a520
after 6 keepalive messages in 35 seconds
error: internal error: received hangup / error event on socket
I tried reproducing that and I get no hang, plus the only difference
is that without -k0 I *sometimes* get:
warning : virKeepAliveTimer:177 : Failed to send keepalive request to
client 0x55555583d630
Other than that, everythign works fine and I only see the reconnection
happen after another command is called. Are you using some kind of
special authentication?
but then it just hangs there. A backtrace shows that it is hanging
trying to reconnect:
(gdb) bt
#0 0x00007ffff39129dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1 0x00007ffff798e3c1 in virNetClientIOEventLoop (client=0x55555586ae10,
thiscall=0x55555586b090) at rpc/virnetclient.c:1514
#2 0x00007ffff798ecbf in virNetClientIO (client=0x55555586ae10,
thiscall=0x55555586b090) at rpc/virnetclient.c:1786
#3 0x00007ffff798f5ab in virNetClientSendInternal (client=0x55555586ae10,
msg=0x55555586ada0, expectReply=true, nonBlock=false)
at rpc/virnetclient.c:1958
#4 0x00007ffff798f648 in virNetClientSendWithReply (client=0x55555586ae10,
msg=0x55555586ada0) at rpc/virnetclient.c:1986
#5 0x00007ffff7990580 in virNetClientProgramCall (prog=0x55555586afd0,
client=0x55555586ae10, serial=0, proc=66, noutfds=0, outfds=0x0,
ninfds=0x0, infds=0x0, args_filter=0x7ffff394f270 <__GI_xdr_void>,
args=0x0, ret_filter=0x7ffff798152c <xdr_remote_auth_list_ret>,
ret=0x7fffffffd6f0) at rpc/virnetclientprogram.c:329
#6 0x00007ffff7975d4c in callFull (conn=0x555555869fb0,
priv=0x55555586ab30,
flags=0, fdin=0x0, fdinlen=0, fdout=0x0, fdoutlen=0x0, proc_nr=66,
args_filter=0x7ffff394f270 <__GI_xdr_void>, args=0x0,
ret_filter=0x7ffff798152c <xdr_remote_auth_list_ret>,
ret=0x7fffffffd6f0 "") at remote/remote_driver.c:6544
#7 0x00007ffff7975e25 in call (conn=0x555555869fb0, priv=0x55555586ab30,
flags=0, proc_nr=66, args_filter=0x7ffff394f270 <__GI_xdr_void>,
args=0x0,
ret_filter=0x7ffff798152c <xdr_remote_auth_list_ret>,
---Type <return> to continue, or q <return> to quit---
ret=0x7fffffffd6f0 "") at remote/remote_driver.c:6566
#8 0x00007ffff795f7f1 in remoteAuthenticate (conn=0x555555869fb0,
priv=0x55555586ab30, auth=0x7ffff7d71520 <virConnectAuthDefault>,
authtype=0x0) at remote/remote_driver.c:3939
#9 0x00007ffff7957f0a in doRemoteOpen (conn=0x555555869fb0,
priv=0x55555586ab30, auth=0x7ffff7d71520 <virConnectAuthDefault>,
flags=0)
at remote/remote_driver.c:973
#10 0x00007ffff795890b in remoteConnectOpen (conn=0x555555869fb0,
auth=0x7ffff7d71520 <virConnectAuthDefault>, flags=0)
at remote/remote_driver.c:1190
#11 0x00007ffff78fc5e5 in do_open (name=0x0,
auth=0x7ffff7d71520 <virConnectAuthDefault>, flags=0) at libvirt.c:1147
#12 0x00007ffff78fd093 in virConnectOpenAuth (name=0x0,
auth=0x7ffff7d71520 <virConnectAuthDefault>, flags=0) at libvirt.c:1390
#13 0x0000555555575a67 in vshConnect (ctl=0x7fffffffdbc0, uri=0x0,
readonly=false) at virsh.c:337
#14 0x0000555555575c23 in vshReconnect (ctl=0x7fffffffdbc0) at virsh.c:383
#15 0x000055555557943a in vshCommandRun (ctl=0x7fffffffdbc0,
cmd=0x5555557f4900) at virsh.c:1853
#16 0x000055555557d8de in main (argc=5, argv=0x7fffffffdda8) at virsh.c:3617
It seems odd that virsh is hanging rather than gracefully exit, because
it is trying too hard to reconnect in spite of being forcefully
disconnected due to a keepalive timeout. But I'm not sure what, if
anything, we could tweak to make this failure mode not require a Ctrl-C
on my end to get rid of the failed virsh. It also reiterates the idea
that we really ought to allow for a user-specified timeout to
virConnect, rather than blocking forever.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
--
libvir-list mailing list
libvir-list(a)redhat.com
https://www.redhat.com/mailman/listinfo/libvir-list
8:05 a.m.
On 05/23/2014 05:29 AM, Martin Kletzander wrote:
On Tue, May 20, 2014 at 05:49:54PM -0600, Eric Blake wrote:
> I'm trying to debug a new virsh command, and had two terminals up, one
> running './run gdb tools/virsh' (I originally ran virsh directly, but
> re-ran under gdb to get a trace) and the other running './run gdb
> daemon/libvirtd'. Because I forgot to use the -k0 argument to disable
> keepalives, and took too long while at a breakpoint on the libvirtd
> terminal, my virsh session tried to report a keepalive failure:
>
I also have an explicit keepalive_interval=3 in my
/etc/libvirt/libvirtd.conf (rather than the default), I don't think I
have any other non-default settings in my conf files at the moment, but
wonder if the choice of server settings matters for reproducing.
I tried reproducing that and I get no hang, plus the only difference
is that without -k0 I *sometimes* get:
warning : virKeepAliveTimer:177 : Failed to send keepalive request to
client 0x55555583d630
Other than that, everythign works fine and I only see the reconnection
happen after another command is called. Are you using some kind of
special authentication?
No, I'm just running 'virsh -c qemu:///system' from a root shell. Maybe
it's the particular virsh command I was running (in my case, 'virsh
blockcommit --wait' with patches not yet upstream, but upstream would be
similar with 'virsh blockcopy --wait') - the single virsh command is
actually a while() loop of API calls to poll for status; it could be
that the reconnect works if between commands that only do one API call,
but because of this particular command calling API in a while loop, it
is not breaking out of the loop properly on a reconnect attempt.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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