[libvirt] FW: Using dlls for Windows provided in http://libvirt.org/sources/win32_experimental/Libvirt-0.8.7-2.exe
5:49 a.m.
Hello libvirt-list,
We have a problem. It concerns CPU usage of libvirt library in Windows. It's not a
problem in Linux. See attach.
At the moment we have a workaround for item 1 - we just calculate the number of handles
which are leaked and restart our service if the number exceeds 10.000
As for item 2 - we have no real workaround. In 99.99% it should not happen, but there is
still 0.01%
In libvirt.log you can find more info as suggested by Daniel.
================================================================
In the attached file, you will find detailed information regarding the case 100 percent
CPU usage.
Our test was performed on the following system:
Windows XP SP3;
Libvirt-0.8.8;
Run the following command: virsh -c qemu+tcp: / /172.17.46.88:135/system
Port 135 was one of the ports on which our service is trying to connect.
================================================================
Could you help us here?
Thanks
Alexander
-----Original Message-----
From: Aliaksandr Chabatar
Sent: Tuesday, March 15, 2011 3:52 PM
To: Ihar Smertsin
Subject: FW: [libvirt] Using dlls for Windows provided in
http://libvirt.org/sources/win32_experimental/Libvirt-0.8.7-2.exe
Hi Ihar,
Could you provide more information (log files, see below) so we could address this issue
to libvir-list(a)redhat.com ?
Mfg
Alexander
-----Original Message-----
From: Daniel P. Berrange [mailto:berrange@redhat.com]
Sent: Tuesday, March 15, 2011 3:08 PM
To: Aliaksandr Chabatar
Cc: Hempfer, Siegfried; Boehme, Alfred; Schnizer, Monika
Subject: Re: [libvirt] Using dlls for Windows provided in
http://libvirt.org/sources/win32_experimental/Libvirt-0.8.7-2.exe
On Tue, Mar 15, 2011 at 04:01:31PM +0200, Aliaksandr Chabatar wrote:
Dear Daniel,
I have another question. It concerns CPU usage of libvirt library
in Windows. It's not a problem in Linux. See attach.
At the moment we have a workaround for item 1 - we just calculate
the number of handles which are leaked and restart our service if
the number exceeds 10.000
It sounds like we have some crazy resource leak in a piece of
code. I'm not too familiar with Windows, but if you re-send
this mail of yours to libvir-list(a)redhat.com, I expect one of
the community members who knows Windows will be able to advise.
As for item 2 - we have no real workaround. In 99.99% it should
not happen, but there is still 0.01%
Yeah, that sounds like some piece of code is missing correct
error checking. It would be useful to try and obtain a couple
of stack traces when it is showing 100% cpu usage. Or capture
a libvirt debug log, eg by setting an environment variable
in your client application
LIBVIRT_LOG_FILTERS="1:libvirt 1:util 1:remote"
LIBVIRT_LOG_OUTPUTS="1:file:libvirt.log"
Again, sending this log + the info from your mail to the libvir-list
would be best.
Daniel
--
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12:09 p.m.
Quite a long mail, I'm skipping all but the original report here.
From: Ihar Smertsin <I.Smertsin(a)sam-solutions.net>
To: Aliaksandr Chabatar <A.Chabatar(a)sam-solutions.net>
Date: Tue, 8 Feb 2011 15:05:59 +0200
Subject: Libvirt issues in windows
Hello Alexandr,
On the client version of the library under Windows detected the following errors:
1. When you call some library functions is a growth of handles of resources.
Growth handles can be found as follows:
run the task manager;
run the utility virsh;
connect this tool to the server is running libvirtd service; (virsh -c qemu + tcp: / /
192.168.117.107/system)
execute any command, for example list;
if we continue to call a command list, then the task manager can be found that the
number of handles will increase by about 5-6,
The exact same situation arises every time you call some library functions, such as:
virConnectListDomains, virConnectNumOfDomains, virDomainLookupByID,
virDomainLookupByName and others;
I can reproduce this problem and fixed it. See
https://www.redhat.com/archives/libvir-list/2011-March/msg00809.html
for the patch. The next libvirt release scheduled for end of March
(IIRC) will contain it.
The problem was that libvirt uses a conditional variable during remote
communication. This conditional variable wasn't freed correctly.
Resulting in leaking one handle per remote call. virsh commands like
list do multiple remote calls resulting in leaking multiple handles at
once.
2. In some cases, there is a growth of CPU resources. It happened in
the following situations:
We have a service that detects different types of virtual systems, including KVM.
This service uses the client library libvirt. Our network has a host that is running
windows 2008, which supports hyper-v virtualization.
Our service is trying to determine the type of virtualization trying to connect to the
system under different protocols.
When the turn of the KVM, then there is the following situation. When we call the
function virConnectOpen with parameter (qemu + tcp: / / 192.168.117.178:135 / system)
error occurs. (Error: internal error received hangup / error event on socket)
And then our service starts to take the CPU up to 20-25%.
I didn't look into this one in detail yet. It could be that something
is not properly cleanup when this error occurs and this results in the
high CPU load. This will need some further investigation.
Matthias
12:13 p.m.
Hello Matthias,
Thanks a lot for your quick response.
I am looking forward for the item#2 solution.
Alexander
-----Original Message-----
From: Matthias Bolte [mailto:matthias.bolte@googlemail.com]
Sent: Thursday, March 17, 2011 6:09 PM
To: Aliaksandr Chabatar
Cc: libvir-list(a)redhat.com; Ihar Smertsin
Subject: Re: [libvirt] FW: Using dlls for Windows provided in
http://libvirt.org/sources/win32_experimental/Libvirt-0.8.7-2.exe
Quite a long mail, I'm skipping all but the original report here.
From: Ihar Smertsin <I.Smertsin(a)sam-solutions.net>
To: Aliaksandr Chabatar <A.Chabatar(a)sam-solutions.net>
Date: Tue, 8 Feb 2011 15:05:59 +0200
Subject: Libvirt issues in windows
Hello Alexandr,
On the client version of the library under Windows detected the following errors:
1. When you call some library functions is a growth of handles of resources.
Growth handles can be found as follows:
run the task manager;
run the utility virsh;
connect this tool to the server is running libvirtd service; (virsh -c qemu + tcp: / /
192.168.117.107/system)
execute any command, for example list;
if we continue to call a command list, then the task manager can be found that the
number of handles will increase by about 5-6,
The exact same situation arises every time you call some library functions, such as:
virConnectListDomains, virConnectNumOfDomains, virDomainLookupByID,
virDomainLookupByName and others;
I can reproduce this problem and fixed it. See
https://www.redhat.com/archives/libvir-list/2011-March/msg00809.html
for the patch. The next libvirt release scheduled for end of March
(IIRC) will contain it.
The problem was that libvirt uses a conditional variable during remote
communication. This conditional variable wasn't freed correctly.
Resulting in leaking one handle per remote call. virsh commands like
list do multiple remote calls resulting in leaking multiple handles at
once.
2. In some cases, there is a growth of CPU resources. It happened in
the following situations:
We have a service that detects different types of virtual systems, including KVM.
This service uses the client library libvirt. Our network has a host that is running
windows 2008, which supports hyper-v virtualization.
Our service is trying to determine the type of virtualization trying to connect to the
system under different protocols.
When the turn of the KVM, then there is the following situation. When we call the
function virConnectOpen with parameter (qemu + tcp: / / 192.168.117.178:135 / system)
error occurs. (Error: internal error received hangup / error event on socket)
And then our service starts to take the CPU up to 20-25%.
I didn't look into this one in detail yet. It could be that something
is not properly cleanup when this error occurs and this results in the
high CPU load. This will need some further investigation.
Matthias
4999
days inactive
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2 comments
2 participants
participants (2)
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Aliaksandr Chabatar -
Matthias Bolte