openstack/cinder
Code Issues Proposed changes

RBD: Run flatten in a different thread when cloning a volume

Browse Source 
The current implementation of create_cloned_volume calls flatten
directly, and this makes whole thread of cinder-volume blocked by that
flatten call. This causes heartbeat timeout in RabbitMQ when cloning
a volume with rbd backend.

This patch makes sure that flatten is executed in a different thread,
to allow heatbeat thread to run while flattening a rbd image.

Closes-Bug: #1898918
Change-Id: I9f28260008117abcebfc96dbe69bf892f5cd14fe
This commit is contained in:
Takashi Kajinami 2020-10-07 09:55:32 +09:00
parent 06bc733ffa
commit bafe440b94
3 changed files with 22 additions and 8 deletions
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11
cinder/tests/unit/volume/drivers/test_rbd.py
View File

@ -1163,6 +1163,9 @@ class RBDTestCase(test.TestCase):
def test_create_cloned_volume_w_flatten(self, mock_enable_repl): def test_create_cloned_volume_w_flatten(self, mock_enable_repl):
self.cfg.rbd_max_clone_depth = 1 self.cfg.rbd_max_clone_depth = 1
client = self.mock_client.return_value
client.__enter__.return_value = client
with mock.patch.object(self.driver, '_get_clone_info') as \ with mock.patch.object(self.driver, '_get_clone_info') as \
mock_get_clone_info: mock_get_clone_info:
mock_get_clone_info.return_value = ( mock_get_clone_info.return_value = (
@ -1192,9 +1195,13 @@ class RBDTestCase(test.TestCase):
.assert_called_once_with('.'.join( .assert_called_once_with('.'.join(
(self.volume_b.name, 'clone_snap')))) (self.volume_b.name, 'clone_snap'))))
# We expect the driver to close both volumes, so 2 is expected self.mock_proxy.assert_called_once_with(
self.driver, self.volume_b.name,
client=client, ioctx=client.ioctx)
# Source volume is closed by direct call of close()
self.assertEqual( self.assertEqual(
2, self.mock_rbd.Image.return_value.close.call_count) 1, self.mock_rbd.Image.return_value.close.call_count)
self.assertTrue(mock_get_clone_depth.called) self.assertTrue(mock_get_clone_depth.called)
mock_enable_repl.assert_not_called() mock_enable_repl.assert_not_called()

12
cinder/volume/drivers/rbd.py
View File

@ -704,11 +704,13 @@ class RBDDriver(driver.CloneableImageVD, driver.MigrateVD,
LOG.info("maximum clone depth (%d) has been reached - " LOG.info("maximum clone depth (%d) has been reached - "
"flattening dest volume", "flattening dest volume",
self.configuration.rbd_max_clone_depth) self.configuration.rbd_max_clone_depth)
dest_volume = self.rbd.Image(client.ioctx, dest_name)
# Flatten destination volume
try: try:
# Flatten destination volume with RBDVolumeProxy(self, dest_name, client=client,
LOG.debug("flattening dest volume %s", dest_name) ioctx=client.ioctx) as dest_volume:
dest_volume.flatten() LOG.debug("flattening dest volume %s", dest_name)
dest_volume.flatten()
except Exception as e: except Exception as e:
msg = (_("Failed to flatten volume %(volume)s with " msg = (_("Failed to flatten volume %(volume)s with "
"error: %(error)s.") % "error: %(error)s.") %
@ -717,8 +719,6 @@ class RBDDriver(driver.CloneableImageVD, driver.MigrateVD,
LOG.exception(msg) LOG.exception(msg)
src_volume.close() src_volume.close()
raise exception.VolumeBackendAPIException(data=msg) raise exception.VolumeBackendAPIException(data=msg)
finally:
dest_volume.close()
try: try:
# remove temporary snap # remove temporary snap

7
releasenotes/notes/bug-1898918-b24a93d7d5aff238.yaml Normal file
View File

@ -0,0 +1,7 @@
---
fixes:
- |
RBD driver `Bug #1898918
<https://bugs.launchpad.net/cinder/+bug/1898918>`_: Fix thread block caused
by the flatten operation during cloning a volume. Now the flatten operation
is executed in a different thread.