openstack/aodh
Code Issues Proposed changes

Improve performance of libvirt inspector requests

Browse Source 
Currently libvirt inspector call _test_connection before every
request. It takes 30% of running time.
In patch we catch libvirt exceptions at runtime and try to restart
a failed request.

Change-Id: Ia776ca5ada841698d652f2749e74aabe57d804eb
This commit is contained in:
Ilya Tyaptin 2014-06-06 15:19:09 +04:00
parent 9936b3469c
commit 6792475c51
1 changed files with 36 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
ceilometer/compute/virt/libvirt/inspector.py
View File

@ -43,6 +43,22 @@ CONF = cfg.CONF
CONF.register_opts(libvirt_opts)
def retry_on_disconnect(function):
def decorator(self, *args, **kwargs):
try:
return function(self, *args, **kwargs)
except libvirt.libvirtError as e:
if (e.get_error_code() == libvirt.VIR_ERR_SYSTEM_ERROR and
e.get_error_domain() in (libvirt.VIR_FROM_REMOTE,
libvirt.VIR_FROM_RPC)):
LOG.debug('Connection to libvirt broken')
self.connection = None
return function(self, *args, **kwargs)
else:
raise
return decorator
class LibvirtInspector(virt_inspector.Inspector):
per_type_uris = dict(uml='uml:///system', xen='xen:///', lxc='lxc:///')
@ -56,28 +72,16 @@ class LibvirtInspector(virt_inspector.Inspector):
'qemu:///system')
def _get_connection(self):
if not self.connection or not self._test_connection():
if not self.connection:
global libvirt
if libvirt is None:
libvirt = __import__('libvirt')
LOG.debug(_('Connecting to libvirt: %s'), self.uri)
LOG.debug('Connecting to libvirt: %s', self.uri)
self.connection = libvirt.openReadOnly(self.uri)
return self.connection
def _test_connection(self):
try:
self.connection.getCapabilities()
return True
except libvirt.libvirtError as e:
if (e.get_error_code() == libvirt.VIR_ERR_SYSTEM_ERROR and
e.get_error_domain() in (libvirt.VIR_FROM_REMOTE,
libvirt.VIR_FROM_RPC)):
LOG.debug(_('Connection to libvirt broke'))
return False
raise
@retry_on_disconnect
def _lookup_by_name(self, instance_name):
try:
return self._get_connection().lookupByName(instance_name)
@ -85,6 +89,10 @@ class LibvirtInspector(virt_inspector.Inspector):
if not libvirt or not isinstance(ex, libvirt.libvirtError):
raise virt_inspector.InspectorException(six.text_type(ex))
error_code = ex.get_error_code()
if (error_code == libvirt.VIR_ERR_SYSTEM_ERROR and
ex.get_error_domain() in (libvirt.VIR_FROM_REMOTE,
libvirt.VIR_FROM_RPC)):
raise
msg = ("Error from libvirt while looking up %(instance_name)s: "
"[Error Code %(error_code)s] "
"%(ex)s" % {'instance_name': instance_name,
@ -92,18 +100,22 @@ class LibvirtInspector(virt_inspector.Inspector):
'ex': ex})
raise virt_inspector.InstanceNotFoundException(msg)
@retry_on_disconnect
def inspect_instance(self, domain_id):
domain = self._get_connection().lookupByID(domain_id)
return virt_inspector.Instance(name=domain.name(),
UUID=domain.UUIDString())
@retry_on_disconnect
def inspect_instances(self):
if self._get_connection().numOfDomains() > 0:
for domain_id in self._get_connection().listDomainsID():
try:
# We skip domains with ID 0 (hypervisors).
if domain_id != 0:
domain = self._get_connection().lookupByID(domain_id)
yield virt_inspector.Instance(name=domain.name(),
UUID=domain.UUIDString())
except libvirt.libvirtError:
# Instance was deleted while listing... ignore it
pass
if domain_id != 0:
try:
yield self.inspect_instance(domain_id)
except libvirt.libvirtError:
# Instance was deleted while listing... ignore it
pass
def inspect_cpus(self, instance_name):
domain = self._lookup_by_name(instance_name)