5:06 a.m.
Hello,
- I am trying to make an application, which would connect to a remote
xen host and fetch some information about total (physical) CPU usage,
total memory usage, network and disk I/O. I have managed to do a remote
statistics grabber for CPU and memory usage using libvirt. I couldn't
find any source of information about libvirt ability to return I/O
numbers. Also haven't found any other solution yet. Any suggestions?
Thank you in advance!
Best regards,
Mindaugas Kiznis
5:10 a.m.
Mindaugas Kiznis wrote:
- I am trying to make an application, which would connect to a remote
xen host and fetch some information about total (physical) CPU usage,
total memory usage, network and disk I/O. I have managed to do a remote
statistics grabber for CPU and memory usage using libvirt. I couldn't
find any source of information about libvirt ability to return I/O
numbers. Also haven't found any other solution yet. Any suggestions?
It's very interesting that you should ask this, because I am
investigating adding network I/O and block I/O stats to libvirt. We
would get the information from /sys/devices/xen-backend/... in the same
way that libxenstat does it at the moment, and pass that up through
libvirt APIs. As with all libvirt-related stuff we need to think about
how it will apply to the other hypervisors that we support and could
support in the future.
You are quite right that there is no facility for this in libvirt right
now (just CPU-/memory-based stats at the moment).
See also: http://et.redhat.com/~rjones/virt-top/
Rich.
--
Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/
Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod
Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in
England and Wales under Company Registration No. 03798903
5:37 a.m.
New subject: [Xen-users] Re: [Libvir] Xen physical host statistics
Thank you for your quick answer. In my opinion, I/O statistics are
critical as CPU, memory usage in data center environment to optimally
plan, arrange, spread VMs in a resource or say Xenhost pool. Since there
are many Xen hosts in my case and this number is growing, it is a need
to monitor each host's resource usage in a centralized console, graphing
engine, etc. Hope to see these additions in the next releases of libvirt.
Best regards,
Mindaugas Kiznis
Richard W.M. Jones wrote:
Mindaugas Kiznis wrote:
> - I am trying to make an application, which would connect to a remote
> xen host and fetch some information about total (physical) CPU usage,
> total memory usage, network and disk I/O. I have managed to do a
> remote statistics grabber for CPU and memory usage using libvirt. I
> couldn't find any source of information about libvirt ability to
> return I/O numbers. Also haven't found any other solution yet. Any
> suggestions?
It's very interesting that you should ask this, because I am
investigating adding network I/O and block I/O stats to libvirt. We
would get the information from /sys/devices/xen-backend/... in the
same way that libxenstat does it at the moment, and pass that up
through libvirt APIs. As with all libvirt-related stuff we need to
think about how it will apply to the other hypervisors that we support
and could support in the future.
You are quite right that there is no facility for this in libvirt
right now (just CPU-/memory-based stats at the moment).
See also: http://et.redhat.com/~rjones/virt-top/
Rich.
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5:54 a.m.
New subject: [Xen-users] Re: [Libvir] Xen physical host statistics
Mindaugas Kiznis wrote:
Thank you for your quick answer. In my opinion, I/O statistics are
critical as CPU, memory usage in data center environment to optimally
plan, arrange, spread VMs in a resource or say Xenhost pool. Since there
are many Xen hosts in my case and this number is growing, it is a need
to monitor each host's resource usage in a centralized console, graphing
engine, etc. Hope to see these additions in the next releases of libvirt.
Absolutely.
As Daniel V said however, defining a suitable, portable structure which
can handle future hypervisors and future devices is non-trivial. I'm
working on it, and when I post patches you can help by reviewing them
against the needs of your program.
Rich.
--
Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/
Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod
Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in
England and Wales under Company Registration No. 03798903
5:52 a.m.
On Fri, Aug 10, 2007 at 11:10:50AM +0100, Richard W.M. Jones wrote:
Mindaugas Kiznis wrote:
>- I am trying to make an application, which would connect to a remote
>xen host and fetch some information about total (physical) CPU usage,
>total memory usage, network and disk I/O. I have managed to do a remote
>statistics grabber for CPU and memory usage using libvirt. I couldn't
>find any source of information about libvirt ability to return I/O
>numbers. Also haven't found any other solution yet. Any suggestions?
It's very interesting that you should ask this, because I am
investigating adding network I/O and block I/O stats to libvirt. We
would get the information from /sys/devices/xen-backend/... in the same
way that libxenstat does it at the moment, and pass that up through
libvirt APIs. As with all libvirt-related stuff we need to think about
how it will apply to the other hypervisors that we support and could
support in the future.
The API design itself doesn't sound trivial at all. First do you want
to collect a range of stats or just one device stat, simpler API vs.
number of RPCs needed. Second there is a API portability problem,
e.g. between different hypervisors, try to get a data structure which
would fit the various engine without loosing too much data. There is
also a potential naming problem for the devices.
Like for the other places in the API where defining a fixed record
structure have proved too challenging, we could fallback to an XML
chunk being passed back, but that would not be my preferred solution.
But if you look at the complexity of sar you realize that it's very
difficult to come back with one kind of statistics pleasing a majority
of users, so either the API is very low level or you need a lot of
flexibility I guess.
Daniel
--
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard | virtualization library http://libvirt.org/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
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4 comments
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participants (3)
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Daniel Veillard -
Mindaugas Kiznis -
Richard W.M. Jones