openstack
/
nova
Code Issues Proposed changes

Merge "External locking for image caching."

This commit is contained in:
Jenkins 2012-08-30 19:34:18 +00:00 committed by Gerrit Code Review
parent 89a1131925 1523fab5ee
commit 9e172ce806
4 changed files with 45 additions and 19 deletions
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3
nova/tests/test_imagebackend.py
View File

@ -35,7 +35,8 @@ class _ImageTestCase(test.TestCase):
def setUp(self):
super(_ImageTestCase, self).setUp()
self.flags(instances_path=self.INSTANCES_PATH)
self.flags(disable_process_locking=True,
instances_path=self.INSTANCES_PATH)
self.INSTANCE = 'instance'
self.NAME = 'fake.vm'
self.TEMPLATE = 'template'

14
nova/tests/test_xenapi.py
View File

@ -146,10 +146,11 @@ class XenAPIVolumeTestCase(stubs.XenAPITestBase):
self.user_id = 'fake'
self.project_id = 'fake'
self.context = context.RequestContext(self.user_id, self.project_id)
self.flags(xenapi_connection_url='test_url',
xenapi_connection_password='test_pass',
self.flags(disable_process_locking=True,
firewall_driver='nova.virt.xenapi.firewall.'
'Dom0IptablesFirewallDriver')
'Dom0IptablesFirewallDriver',
xenapi_connection_url='test_url',
xenapi_connection_password='test_pass')
db_fakes.stub_out_db_instance_api(self.stubs)
self.instance_values = {'id': 1,
'project_id': self.user_id,
@ -260,11 +261,12 @@ class XenAPIVMTestCase(stubs.XenAPITestBase):
def setUp(self):
super(XenAPIVMTestCase, self).setUp()
self.network = importutils.import_object(FLAGS.network_manager)
self.flags(xenapi_connection_url='test_url',
xenapi_connection_password='test_pass',
self.flags(disable_process_locking=True,
instance_name_template='%d',
firewall_driver='nova.virt.xenapi.firewall.'
'Dom0IptablesFirewallDriver')
'Dom0IptablesFirewallDriver',
xenapi_connection_url='test_url',
xenapi_connection_password='test_pass',)
xenapi_fake.create_local_srs()
xenapi_fake.create_local_pifs()
db_fakes.stub_out_db_instance_api(self.stubs)

34
nova/utils.py
View File

@ -661,7 +661,7 @@ else:
_semaphores = weakref.WeakValueDictionary()
def synchronized(name, external=False):
def synchronized(name, external=False, lock_path=None):
"""Synchronization decorator.
Decorating a method like so::
@ -688,6 +688,10 @@ def synchronized(name, external=False):
multiple processes. This means that if two different workers both run a
a method decorated with @synchronized('mylock', external=True), only one
of them will execute at a time.
The lock_path keyword argument is used to specify a special location for
external lock files to live. If nothing is set, then FLAGS.lock_path is
used as a default.
"""
def wrap(f):
@ -703,9 +707,6 @@ def synchronized(name, external=False):
# (only valid in greenthreads)
_semaphores[name] = sem
LOG.debug(_('Attempting to grab semaphore "%(lock)s" for method '
'"%(method)s"...'), {'lock': name,
'method': f.__name__})
with sem:
LOG.debug(_('Got semaphore "%(lock)s" for method '
'"%(method)s"...'), {'lock': name,
@ -714,8 +715,25 @@ def synchronized(name, external=False):
LOG.debug(_('Attempting to grab file lock "%(lock)s" for '
'method "%(method)s"...'),
{'lock': name, 'method': f.__name__})
lock_path = FLAGS.lock_path or tempfile.mkdtemp()
lock_file_path = os.path.join(lock_path, 'nova-%s' % name)
cleanup_dir = False
def wrap_mkdtemp():
cleanup_dir = True
return tempfile.mkdtemp()
# We need a copy of lock_path because it is non-local
local_lock_path = lock_path
if not local_lock_path:
local_lock_path = FLAGS.lock_path or wrap_mkdtemp()
if not os.path.exists(local_lock_path):
ensure_tree(local_lock_path)
# NOTE(mikal): the lock name cannot contain directory
# separators
safe_name = name.replace(os.sep, '_')
lock_file_path = os.path.join(local_lock_path,
'nova-%s' % safe_name)
lock = InterProcessLock(lock_file_path)
try:
with lock:
@ -727,8 +745,8 @@ def synchronized(name, external=False):
# NOTE(vish): This removes the tempdir if we needed
# to create one. This is used to cleanup
# the locks left behind by unit tests.
if not FLAGS.lock_path:
shutil.rmtree(lock_path)
if cleanup_dir:
shutil.rmtree(local_lock_path)
else:
retval = f(*args, **kwargs)

13
nova/virt/libvirt/imagebackend.py
View File

@ -61,6 +61,11 @@ class Image(object):
self.driver_format = driver_format
self.is_block_dev = is_block_dev
# NOTE(mikal): We need a lock directory which is shared along with
# instance files, to cover the scenario where multiple compute nodes
# are trying to create a base file at the same time
self.lock_path = os.path.join(FLAGS.instances_path, 'locks')
@abc.abstractmethod
def create_image(self, prepare_template, base, size, *args, **kwargs):
"""Create image from template.
@ -106,7 +111,7 @@ class Image(object):
:fname: Template name
:size: Size of created image in bytes (optional)
"""
@utils.synchronized(fname)
@utils.synchronized(fname, external=True, lock_path=self.lock_path)
def call_if_not_exists(target, *args, **kwargs):
if not os.path.exists(target):
fn(target=target, *args, **kwargs)
@ -129,7 +134,7 @@ class Raw(Image):
instance, name)
def create_image(self, prepare_template, base, size, *args, **kwargs):
@utils.synchronized(base)
@utils.synchronized(base, external=True, lock_path=self.lock_path)
def copy_raw_image(base, target, size):
libvirt_utils.copy_image(base, target)
if size:
@ -153,7 +158,7 @@ class Qcow2(Image):
instance, name)
def create_image(self, prepare_template, base, size, *args, **kwargs):
@utils.synchronized(base)
@utils.synchronized(base, external=True, lock_path=self.lock_path)
def copy_qcow2_image(base, target, size):
qcow2_base = base
if size:
@ -189,7 +194,7 @@ class Lvm(Image):
self.sparse = FLAGS.libvirt_sparse_logical_volumes
def create_image(self, prepare_template, base, size, *args, **kwargs):
@utils.synchronized(base)
@utils.synchronized(base, external=True, lock_path=self.lock_path)
def create_lvm_image(base, size):
base_size = disk.get_disk_size(base)
resize = size > base_size