Fix: Create new cache entry when xtremio reaches snap limit

When we reach xtremio_volumes_per_glance_cache, it is not able
to create more clones for the image-volume therefore requires to
create a new cache entry.
Keeping in mind the case in [1], we can get CinderException for
various reasons from different drivers during the clone operation.
So we define a new exception for the xtremio driver to force create
a new cache entry when the limit reaches and not enforce the same
for other drivers.

[1] https://bugs.launchpad.net/cinder/+bug/1552734

Closes-Bug: #1858169

Change-Id: I2bf964d5a7b2048db9be1ea3eb97cd517e112c5b
(cherry picked from commit d22e54c254)
This commit is contained in:
whoami-rajat 2019-12-20 13:59:35 +00:00 committed by Rajat Dhasmana
parent 900f769f59
commit 7cdb1aeb62
4 changed files with 54 additions and 41 deletions

View File

@ -1117,3 +1117,8 @@ class CinderAcceleratorError(CinderException):
"Command %(cmd)s execution failed.\n"
"%(description)s\n"
"Reason: %(reason)s")
class SnapshotLimitReached(CinderException):
message = _("Exceeded the configured limit of "
"%(set_limit)s snapshots per volume.")

View File

@ -1559,53 +1559,52 @@ class CreateVolumeFlowManagerImageCacheTestCase(test.TestCase):
image_location = 'someImageLocationStr'
image_id = fakes.IMAGE_ID
image_meta = mock.MagicMock()
image_info = imageutils.QemuImgInfo()
image_info.virtual_size = '1073741824'
mock_qemu_info.return_value = image_info
volume = fake_volume.fake_volume_obj(self.ctxt, size=1,
host='foo@bar#pool')
image_volume = fake_volume.fake_db_volume(size=2)
self.mock_db.volume_create.return_value = image_volume
self.mock_driver.clone_image.return_value = (None, False)
self.flags(verify_glance_signatures='disabled')
if cloning_supported:
mock_create_from_src.side_effect = exception.CinderException(
'Error during cloning')
else:
mock_create_from_src.side_effect = NotImplementedError(
'Driver does not support clone')
manager = create_volume_manager.CreateVolumeFromSpecTask(
self.mock_volume_manager,
self.mock_db,
self.mock_driver,
image_volume_cache=self.mock_cache
)
model_update = manager._create_from_image_cache_or_download(
self.ctxt,
volume,
image_location,
image_id,
image_meta,
self.mock_image_service,
update_cache=False)
if cloning_supported:
mock_create_from_src.side_effect = exception.SnapshotLimitReached(
'Error during cloning')
self.assertRaises(
exception.SnapshotLimitReached,
manager._create_from_image,
self.ctxt,
volume,
image_location,
image_id,
image_meta,
self.mock_image_service)
else:
mock_create_from_src.side_effect = NotImplementedError(
'Driver does not support clone')
model_update = manager._create_from_image(
self.ctxt,
volume,
image_location,
image_id,
image_meta,
self.mock_image_service)
mock_create_from_img_dl.assert_called_once()
self.assertEqual(mock_create_from_img_dl.return_value,
model_update)
# Ensure cloning was attempted and that it failed
mock_create_from_src.assert_called_once()
mock_create_from_img_dl.assert_called_once()
self.assertEqual(mock_create_from_img_dl.return_value, model_update)
# Ensure a new cache entry is created when cloning fails, but
# only when the driver supports cloning.
if cloning_supported:
(self.mock_volume_manager.
_create_image_cache_volume_entry.assert_called_once())
else:
(self.mock_volume_manager.
_create_image_cache_volume_entry.assert_not_called())
with mock.patch(
'cinder.volume.flows.manager.create_volume.'
'CreateVolumeFromSpecTask') as volume_manager:
(volume_manager.CreateVolumeFromSpecTask.
_create_from_image_cache_or_download.called_once())
(volume_manager.CreateVolumeFromSpecTask.
_create_from_image_cache.called_once())
@mock.patch('cinder.volume.flows.manager.create_volume.'
'CreateVolumeFromSpecTask.'

View File

@ -552,8 +552,7 @@ class XtremIOVolumeDriver(san.SanDriver):
src_vref['id'])
limit = self.configuration.safe_get('xtremio_volumes_per_glance_cache')
if cache and limit and limit > 0 and limit <= vol['num-of-dest-snaps']:
raise exception.CinderException('Exceeded the configured limit of '
'%d snapshots per volume' % limit)
raise exception.SnapshotLimitReached(set_limit=limit)
try:
self.client.create_snapshot(src_vref['id'], volume['id'])
except XtremIOSnapshotsLimitExceeded as e:

View File

@ -772,6 +772,14 @@ class CreateVolumeFromSpecTask(flow_utils.CinderTask):
cache_entry['volume_id']
)
return model_update, True
except exception.SnapshotLimitReached:
# If this exception occurred when cloning the image-volume,
# it is because the image-volume reached its snapshot limit.
# Delete current cache entry and create a "fresh" entry
# NOTE: This will not delete the existing image-volume and
# only delete the cache entry
with excutils.save_and_reraise_exception():
self.image_volume_cache.evict(context, cache_entry)
except NotImplementedError:
LOG.warning('Backend does not support creating image-volume '
'clone. Image will be downloaded from Glance.')
@ -855,17 +863,18 @@ class CreateVolumeFromSpecTask(flow_utils.CinderTask):
image_id,
image_meta
)
except exception.SnapshotLimitReached:
# This exception will be handled by the caller's
# (_create_from_image) retry decorator
with excutils.save_and_reraise_exception():
LOG.debug("Snapshot limit reached. Creating new "
"image-volume.")
except exception.CinderException as e:
LOG.warning('Failed to create volume from image-volume '
'cache, image will be downloaded from Glance. '
'Error: %(exception)s',
{'exception': e})
# If an exception occurred when cloning the image-volume,
# it may be the image-volume reached its snapshot limit.
# Create another "fresh" cache entry.
update_cache = True
# Don't cache unless directed.
if not cloned and update_cache:
should_create_cache_entry = True
@ -957,6 +966,7 @@ class CreateVolumeFromSpecTask(flow_utils.CinderTask):
return model_update
@utils.retry(exception.SnapshotLimitReached, retries=1)
def _create_from_image(self, context, volume,
image_location, image_id, image_meta,
image_service, **kwargs):