Error getting VM-informations with Python on Xen 3.0.2

Error getting VM-informations with Python on Xen 3.0.2

[Thorolf Godawa]

Hi all,

I wrote a small python-script to monitor the status of the started VMs
based on the xenmon.py and the following code I got from Anthony Liguori:

----------------------------------------
import sys
sys.path.append('/usr/lib/python')
sys.path.append('/usr/lib64/python')

from xen.xend.XendClient import server
from xen.xend import sxp

def parse_doms_info(info):
     def get_info(n, t, d):
         return t(sxp.child_value(info, n, d))

     return {
         'dom'      : get_info('domid',        int,   -1),
         'name'     : get_info('name',         str,   '??'),
         'mem'      : get_info('memory',       int,   0),
         'vcpus'    : get_info('online_vcpus', int,   0),
         'state'    : get_info('state',        str,   '??'),
         'cpu_time' : get_info('cpu_time',     float, 0),
         'ssidref'  : get_info('ssidref',      int,   0),
         }

doms = server.xend_list_domains()

print 'Name                              ID Mem(MiB) VCPUs State  Time(s)'
for dom in doms:
     d = parse_doms_info(dom)
     if (d['ssidref'] != 0):
         d['ssidstr'] = (" s:%04x/p:%04x" %
                         ((d['ssidref'] >> 16) & 0xffff,
                           d['ssidref']        & 0xffff))
     else:
         d['ssidstr'] = ""
     print ("%(name)-32s %(dom)3d %(mem)8d %(vcpus)5d %(state)5s%
(cpu_time)7.1f% (ssidstr)s" % d)
----------------------------------------

I wrote the script on SUSE SLES 10.0 Beta 3 with Xen 3.0_8659-2.
Unfortunately this script (and therefor my one too) ist not running
anymore with the latest SUSE SLES 10.0 Beta 9 that includes Xen
3.0.2_09434-2 :-(

It breaks at line "doms = server.xend_list_domains()" with the following
error:

----------------------------------------
Traceback (most recent call last):
   File "xentest1.py", line 22, in ?
     doms = server.xend_list_domains()
   File "/usr/lib/python2.4/xmlrpclib.py", line 1096, in __call__
     return self.__send(self.__name, args)
   File "/usr/lib/python2.4/xmlrpclib.py", line 1383, in __request
     verbose=self.__verbose
   File "/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py", line
46, in request
     return Transport.request(self, host, '/RPC2', request_body, verbose)
   File "/usr/lib/python2.4/xmlrpclib.py", line 1147, in request
     return self._parse_response(h.getfile(), sock)
   File "/usr/lib/python2.4/xmlrpclib.py", line 1286, in _parse_response
     return u.close()
   File "/usr/lib/python2.4/xmlrpclib.py", line 744, in close
     raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1: 'Traceback (most recent call last):\n  File
"/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py", line 74, in
_marshaled_dispatch\n    response = self._dispatch(method, params)\n
File "/usr/lib/python2.4/SimpleXMLRPCServer.py", line 408, in
_dispatch\n    raise Exception(\'method "%s" is not supported\' %
method)\nException: method "xend_list_domains" is not supported\n'>
----------------------------------------

If I see right it now uses "/usr/lib/python2.4/SimpleXMLRPCServer.py"
(what does not exist in Xen 3.0_8659-2) and breaks because the method
"xend_list_domains" is not supported anymore I use to get the
domain-informations with the script.

Is there a better way to get the VM-status like name, memory, state,
CPU-usage etc. via Python than using the mechanism from xenmon.py and
the above one?

Thanks a lot for your answers,
-- 

Chau y hasta luego,

Thorolf

------------------------------------------------------------------
e-Mail:   mailto:Thorolf@Godawa.de                      \|/
                                                        /'~'\
Homepage: http://www.godawa.de                        ( o o )
--------------------------------------------------oOOO--(_)--OOOo-\x1a

Re: Error getting VM-informations with Python on Xen 3.0.2

[Ewan Mellor]

On Wed, Apr 05, 2006 at 09:24:42PM +0200, Thorolf Godawa wrote:

> Hi all,
> 
> I wrote a small python-script to monitor the status of the started VMs
> based on the xenmon.py and the following code I got from Anthony Liguori:
>
> [Snip]
>
> It breaks at line "doms = server.xend_list_domains()" with the following
> error:
> 
> ----------------------------------------
> Traceback (most recent call last):
>   File "xentest1.py", line 22, in ?
>     doms = server.xend_list_domains()
>   File "/usr/lib/python2.4/xmlrpclib.py", line 1096, in __call__
>     return self.__send(self.__name, args)
>   File "/usr/lib/python2.4/xmlrpclib.py", line 1383, in __request
>     verbose=self.__verbose
>   File "/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py", line
> 46, in request
>     return Transport.request(self, host, '/RPC2', request_body, verbose)
>   File "/usr/lib/python2.4/xmlrpclib.py", line 1147, in request
>     return self._parse_response(h.getfile(), sock)
>   File "/usr/lib/python2.4/xmlrpclib.py", line 1286, in _parse_response
>     return u.close()
>   File "/usr/lib/python2.4/xmlrpclib.py", line 744, in close
>     raise Fault(**self._stack[0])
> xmlrpclib.Fault: <Fault 1: 'Traceback (most recent call last):\n  File
> "/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py", line 74, in
> _marshaled_dispatch\n    response = self._dispatch(method, params)\n
> File "/usr/lib/python2.4/SimpleXMLRPCServer.py", line 408, in
> _dispatch\n    raise Exception(\'method "%s" is not supported\' %
> method)\nException: method "xend_list_domains" is not supported\n'>
> ----------------------------------------
> 
> If I see right it now uses "/usr/lib/python2.4/SimpleXMLRPCServer.py"
> (what does not exist in Xen 3.0_8659-2) and breaks because the method
> "xend_list_domains" is not supported anymore I use to get the
> domain-informations with the script.
> 
> Is there a better way to get the VM-status like name, memory, state,
> CPU-usage etc. via Python than using the mechanism from xenmon.py and
> the above one?

Try server.xend.domains(True).  This changed with the new XML-RPC interface,
courtesy of the aforementioned hacker.

Ewan.

Re: Error getting VM-informations with Python on Xen 3.0.2

[Thorolf Godawa]

Hi Ewan,

 >Try server.xend.domains(True).  This changed with the new XML-RPC
 >interface, courtesy of the aforementioned hacker.
thanks a lot, this solved my problem :-)))

Is there any documentation how to use these Python-interfaces?
-- 

Chau y hasta luego,

Thorolf

Re: Error getting VM-informations with Python on Xen 3.0.2

[Ewan Mellor]

On Thu, Apr 06, 2006 at 11:02:56AM +0200, Thorolf Godawa wrote:

> Hi Ewan,
> 
> >Try server.xend.domains(True).  This changed with the new XML-RPC
> >interface, courtesy of the aforementioned hacker.
> thanks a lot, this solved my problem :-)))
> 
> Is there any documentation how to use these Python-interfaces?

No, I'm afraid not.  The XML-RPC interface will stabilise in time, but at the
moment, it's not documented.  The Python interface on top of the XML-RPC is
not documented either, since it's only a stub onto the XML-RPC, now.

The only interfaces that are guaranteed currently are those required to
support old guests on new hypervisors.  Everything else is subject to change.
The best way for you to keep up is to get your code into the tree, preferably
with a unit test or two, and then there's a fair chance that it won't be
broken as things change.

Ewan.

Re: Error getting VM-informations with Python on Xen 3.0.2

[Ewan Mellor]

On Thu, Apr 06, 2006 at 02:05:23PM +0100, Ewan Mellor wrote:

> On Thu, Apr 06, 2006 at 11:02:56AM +0200, Thorolf Godawa wrote:
> 
> > Hi Ewan,
> > 
> > >Try server.xend.domains(True).  This changed with the new XML-RPC
> > >interface, courtesy of the aforementioned hacker.
> > thanks a lot, this solved my problem :-)))
> > 
> > Is there any documentation how to use these Python-interfaces?
> 
> No, I'm afraid not.  The XML-RPC interface will stabilise in time, but at the
> moment, it's not documented.  The Python interface on top of the XML-RPC is
> not documented either, since it's only a stub onto the XML-RPC, now.
> 
> The only interfaces that are guaranteed currently are those required to
> support old guests on new hypervisors.  Everything else is subject to change.
> The best way for you to keep up is to get your code into the tree, preferably
> with a unit test or two, and then there's a fair chance that it won't be
> broken as things change.

And improvements to the documentation are always welcome: if you want to write
up a tutorial, it would be gratefully received.

Ewan.

Error getting VM-informations with Python on Xen 3.0.2

[Thorolf Godawa]

Hi all,

I wrote a small python-script to monitor the status of the started VMs 
based on the xenmon.py and the following code I got from Anthony Liguori:

----------------------------------------
import sys
sys.path.append('/usr/lib/python')
sys.path.append('/usr/lib64/python')

from xen.xend.XendClient import server
from xen.xend import sxp

def parse_doms_info(info):
     def get_info(n, t, d):
         return t(sxp.child_value(info, n, d))

     return {
         'dom'      : get_info('domid',        int,   -1),
         'name'     : get_info('name',         str,   '??'),
         'mem'      : get_info('memory',       int,   0),
         'vcpus'    : get_info('online_vcpus', int,   0),
         'state'    : get_info('state',        str,   '??'),
         'cpu_time' : get_info('cpu_time',     float, 0),
         'ssidref'  : get_info('ssidref',      int,   0),
         }

doms = server.xend_list_domains()

print 'Name                              ID Mem(MiB) VCPUs State  Time(s)'
for dom in doms:
     d = parse_doms_info(dom)
     if (d['ssidref'] != 0):
         d['ssidstr'] = (" s:%04x/p:%04x" %
                         ((d['ssidref'] >> 16) & 0xffff,
                           d['ssidref']        & 0xffff))
     else:
         d['ssidstr'] = ""
     print ("%(name)-32s %(dom)3d %(mem)8d %(vcpus)5d %(state)5s% 
(cpu_time)7.1f% (ssidstr)s" % d)
----------------------------------------

I wrote the script on SUSE SLES 10.0 Beta 3 with Xen 3.0_8659-2. 
Unfortunately this script (and therefor my one too) ist not running 
anymore with the latest SUSE SLES 10.0 Beta 9 that includes Xen 
3.0.2_09434-2 :-(

It breaks at line "doms = server.xend_list_domains()" with the following 
error:

----------------------------------------
Traceback (most recent call last):
   File "xentest1.py", line 22, in ?
     doms = server.xend_list_domains()
   File "/usr/lib/python2.4/xmlrpclib.py", line 1096, in __call__
     return self.__send(self.__name, args)
   File "/usr/lib/python2.4/xmlrpclib.py", line 1383, in __request
     verbose=self.__verbose
   File "/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py", line 
46, in request
     return Transport.request(self, host, '/RPC2', request_body, verbose)
   File "/usr/lib/python2.4/xmlrpclib.py", line 1147, in request
     return self._parse_response(h.getfile(), sock)
   File "/usr/lib/python2.4/xmlrpclib.py", line 1286, in _parse_response
     return u.close()
   File "/usr/lib/python2.4/xmlrpclib.py", line 744, in close
     raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1: 'Traceback (most recent call last):\n  File 
"/usr/lib/python2.4/site-packages/xen/util/xmlrpclib2.py", line 74, in 
_marshaled_dispatch\n    response = self._dispatch(method, params)\n 
File "/usr/lib/python2.4/SimpleXMLRPCServer.py", line 408, in 
_dispatch\n    raise Exception(\'method "%s" is not supported\' % 
method)\nException: method "xend_list_domains" is not supported\n'>
----------------------------------------

If I see right it now uses "/usr/lib/python2.4/SimpleXMLRPCServer.py" 
(what does not exist in Xen 3.0_8659-2) and breaks because the method 
"xend_list_domains" is not supported anymore I use to get the 
domain-informations with the script.

Is there a better way to get the VM-status like name, memory, state, 
CPU-usage etc. via Python than using the mechanism from xenmon.py and 
the above one?

Thanks a lot for your answers,
-- 

Chau y hasta luego,

Thorolf