openstack
/
nova
Code Issues Proposed changes

Merge "libvirt: remove live_migration_progress_timeout config"

This commit is contained in:
Zuul 2018-12-15 19:33:08 +00:00 committed by Gerrit Code Review
parent 35ee7edd94 4c3698c0b6
commit 4022171a61
7 changed files with 23 additions and 192 deletions
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13
doc/source/admin/live-migration-usage.rst
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@ -254,19 +254,6 @@ out:
WARNING nova.virt.libvirt.migration [req-...] [instance: ...]
live migration not completed after 1800 sec
The Compute service also cancels migrations when the memory copy seems to make
no progress. This feature is `disabled by default`_, but it can be enabled
using the configuration parameter
:oslo.config:option:`libvirt.live_migration_progress_timeout`. Should
this be the case, you may find the following message in the log:
.. code-block:: console
WARNING nova.virt.libvirt.migration [req-...] [instance: ...]
live migration stuck for 150 sec
.. _disabled by default: https://review.openstack.org/#/c/431635/
Addressing migration timeouts
-----------------------------

22
nova/conf/libvirt.py
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@ -390,24 +390,6 @@ Related options:
* live_migration_downtime
* live_migration_downtime_steps
* live_migration_downtime_delay
"""),
cfg.IntOpt('live_migration_progress_timeout',
default=0,
deprecated_for_removal=True,
deprecated_reason="""
Serious bugs found in this feature, see
https://bugs.launchpad.net/nova/+bug/1644248 for details.
""",
mutable=True,
help="""
Time to wait, in seconds, for migration to make forward progress in
transferring data before aborting the operation.
Set to 0 to disable timeouts.
This is deprecated, and now disabled by default because we have found serious
bugs in this feature that caused false live-migration timeout failures. This
feature will be removed or replaced in a future release.
"""),
cfg.StrOpt('live_migration_timeout_action',
default='abort',
@ -434,9 +416,7 @@ mode, i.e., switch the active VM to the one on the destination node before the
migration is complete, therefore ensuring an upper bound on the memory that
needs to be transferred. Post-copy requires libvirt>=1.3.3 and QEMU>=2.5.0.
When permitted, post-copy mode will be automatically activated if a
live-migration memory copy iteration does not make percentage increase of at
least 10% over the last iteration, or will be automatically activated if
When permitted, post-copy mode will be automatically activated if
we reach the timeout defined by ``live_migration_completion_timeout`` and
``live_migration_timeout_action`` is set to 'force_complete'. Note if you
change to no timeout or choose to use 'abort',

97
nova/tests/unit/virt/libvirt/test_driver.py
View File

@ -11285,7 +11285,6 @@ class LibvirtConnTestCase(test.NoDBTestCase,
def test_live_migration_monitor_downtime(self, mock_downtime_steps,
mock_set_downtime):
self.flags(live_migration_completion_timeout=1000000,
live_migration_progress_timeout=1000000,
group='libvirt')
# We've setup 4 fake downtime steps - first value is the
# time delay, second is the downtime value
@ -11332,7 +11331,6 @@ class LibvirtConnTestCase(test.NoDBTestCase,
def test_live_migration_monitor_completion(self):
self.flags(live_migration_completion_timeout=100,
live_migration_progress_timeout=1000000,
group='libvirt')
# Each one of these fake times is used for time.time()
# when a new domain_info_records entry is consumed.
@ -11362,101 +11360,6 @@ class LibvirtConnTestCase(test.NoDBTestCase,
fake_times, self.EXPECT_ABORT,
expected_mig_status='cancelled')
def test_live_migration_monitor_progress(self):
self.flags(live_migration_completion_timeout=1000000,
live_migration_progress_timeout=150,
group='libvirt')
# Each one of these fake times is used for time.time()
# when a new domain_info_records entry is consumed.
fake_times = [0, 40, 80, 120, 160, 200, 240, 280, 320]
# A normal sequence where see all the normal job states
domain_info_records = [
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_NONE),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=90),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=90),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=90),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=90),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=90),
"thread-finish",
"domain-stop",
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_CANCELLED),
]
self._test_live_migration_monitoring(domain_info_records,
fake_times, self.EXPECT_ABORT,
expected_mig_status='cancelled')
def test_live_migration_monitor_progress_zero_data_remaining(self):
self.flags(live_migration_completion_timeout=1000000,
live_migration_progress_timeout=150,
group='libvirt')
# Each one of these fake times is used for time.time()
# when a new domain_info_records entry is consumed.
fake_times = [0, 40, 80, 120, 160, 200, 240, 280, 320]
# A normal sequence where see all the normal job states
domain_info_records = [
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_NONE),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=0),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=90),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=70),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=50),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=30),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=10),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED, data_remaining=0),
"thread-finish",
"domain-stop",
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_FAILED),
]
self._test_live_migration_monitoring(domain_info_records,
fake_times, self.EXPECT_FAILURE)
@mock.patch('nova.virt.libvirt.migration.should_switch_to_postcopy')
@mock.patch.object(libvirt_driver.LibvirtDriver,
"_is_post_copy_enabled")
def test_live_migration_monitor_postcopy_switch(self,
mock_postcopy_enabled, mock_should_switch):
# A normal sequence where migration is switched to postcopy mode
mock_postcopy_enabled.return_value = True
switch_values = [False, False, True]
mock_should_switch.return_value = switch_values
domain_info_records = [
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_NONE),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED),
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_UNBOUNDED),
"thread-finish",
"domain-stop",
libvirt_guest.JobInfo(
type=fakelibvirt.VIR_DOMAIN_JOB_COMPLETED),
]
self._test_live_migration_monitoring(domain_info_records, [],
self.EXPECT_SUCCESS,
expected_switch=True)
@mock.patch.object(libvirt_driver.LibvirtDriver,
"_is_post_copy_enabled")
def test_live_migration_monitor_force_complete_postcopy(self,

21
nova/tests/unit/virt/libvirt/test_migration.py
View File

@ -974,35 +974,20 @@ class MigrationMonitorTestCase(test.NoDBTestCase):
self.assertEqual(migration.find_job_type(self.guest, self.instance),
fakelibvirt.VIR_DOMAIN_JOB_FAILED)
def test_live_migration_abort_stuck(self):
# Progress time exceeds progress timeout
self.assertTrue(migration.should_trigger_timeout_action(
self.instance, 5000, 1000, 2000, 4500, 9000, "running"))
def test_live_migration_abort_no_prog_timeout(self):
# Progress timeout is disabled
self.assertFalse(migration.should_trigger_timeout_action(
self.instance, 5000, 1000, 0, 4500, 9000, "running"))
def test_live_migration_abort_not_stuck(self):
# Progress time is less than progress timeout
self.assertFalse(migration.should_trigger_timeout_action(
self.instance, 5000, 4500, 2000, 4500, 9000, "running"))
def test_live_migration_abort_too_long(self):
# Elapsed time is over completion timeout
self.assertTrue(migration.should_trigger_timeout_action(
self.instance, 5000, 4500, 2000, 4500, 2000, "running"))
self.instance, 4500, 2000, "running"))
def test_live_migration_abort_no_comp_timeout(self):
# Completion timeout is disabled
self.assertFalse(migration.should_trigger_timeout_action(
self.instance, 5000, 4500, 2000, 4500, 0, "running"))
self.instance, 4500, 0, "running"))
def test_live_migration_abort_still_working(self):
# Elapsed time is less than completion timeout
self.assertFalse(migration.should_trigger_timeout_action(
self.instance, 5000, 4500, 2000, 4500, 9000, "running"))
self.instance, 4500, 9000, "running"))
def test_live_migration_postcopy_switch(self):
# Migration progress is not fast enough

30
nova/virt/libvirt/driver.py
View File

@ -7333,9 +7333,6 @@ class LibvirtDriver(driver.ComputeDriver):
n = 0
start = time.time()
progress_time = start
progress_watermark = None
previous_data_remaining = -1
is_post_copy_enabled = self._is_post_copy_enabled(migration_flags)
while True:
info = guest.get_job_info()
@ -7370,13 +7367,6 @@ class LibvirtDriver(driver.ComputeDriver):
now = time.time()
elapsed = now - start
if ((progress_watermark is None) or
(progress_watermark == 0) or
(progress_watermark > info.data_remaining)):
progress_watermark = info.data_remaining
progress_time = now
progress_timeout = CONF.libvirt.live_migration_progress_timeout
completion_timeout = int(
CONF.libvirt.live_migration_completion_timeout * data_gb)
# NOTE(yikun): Check the completion timeout to determine
@ -7386,8 +7376,8 @@ class LibvirtDriver(driver.ComputeDriver):
# if available else the VM will be suspended, otherwise the
# live migrate operation will be aborted.
if libvirt_migrate.should_trigger_timeout_action(
instance, now, progress_time, progress_timeout,
elapsed, completion_timeout, migration.status):
instance, elapsed, completion_timeout,
migration.status):
timeout_act = CONF.libvirt.live_migration_timeout_action
if timeout_act == 'force_complete':
self.live_migration_force_complete(instance)
@ -7402,15 +7392,6 @@ class LibvirtDriver(driver.ComputeDriver):
self._clear_empty_migration(instance)
raise
if (is_post_copy_enabled and
libvirt_migrate.should_switch_to_postcopy(
info.memory_iteration, info.data_remaining,
previous_data_remaining, migration.status)):
libvirt_migrate.trigger_postcopy_switch(guest,
instance,
migration)
previous_data_remaining = info.data_remaining
curdowntime = libvirt_migrate.update_downtime(
guest, instance, curdowntime,
downtime_steps, elapsed)
@ -7453,13 +7434,6 @@ class LibvirtDriver(driver.ComputeDriver):
"processed_memory": info.memory_processed,
"remaining_memory": info.memory_remaining,
"total_memory": info.memory_total}, instance=instance)
if info.data_remaining > progress_watermark:
lg("Data remaining %(remaining)d bytes, "
"low watermark %(watermark)d bytes "
"%(last)d seconds ago",
{"remaining": info.data_remaining,
"watermark": progress_watermark,
"last": (now - progress_time)}, instance=instance)
n = n + 1
elif info.type == libvirt.VIR_DOMAIN_JOB_COMPLETED:

18
nova/virt/libvirt/migration.py
View File

@ -376,23 +376,17 @@ def find_job_type(guest, instance):
return libvirt.VIR_DOMAIN_JOB_FAILED
def should_trigger_timeout_action(instance, now,
progress_time, progress_timeout,
elapsed, completion_timeout,
def should_trigger_timeout_action(instance, elapsed, completion_timeout,
migration_status):
"""Determine if the migration timeout action should be triggered
:param instance: a nova.objects.Instance
:param now: current time in secs since epoch
:param progress_time: when progress was last made in secs since epoch
:param progress_timeout: time in secs to allow for progress
:param elapsed: total elapsed time of migration in secs
:param completion_timeout: time in secs to allow for completion
:param migration_status: current status of the migration
Check the progress and completion timeouts to determine if either
of them have been hit, and should thus cause migration timeout action to
be triggered.
Check the completion timeout to determine if it has been hit,
and should thus cause migration timeout action to be triggered.
Avoid migration to be aborted or triggered post-copy again if it is
running in post-copy mode
@ -406,12 +400,6 @@ def should_trigger_timeout_action(instance, now,
if migration_status == 'running (post-copy)':
return False
if (progress_timeout != 0 and
(now - progress_time) > progress_timeout):
LOG.warning("Live migration stuck for %d sec",
(now - progress_time), instance=instance)
return True
if elapsed > completion_timeout:
LOG.warning("Live migration not completed after %d sec",
completion_timeout, instance=instance)

14
releasenotes/notes/live-migration-force-after-timeout-54f2a4b631d295bb.yaml
View File

@ -13,3 +13,17 @@ features:
The ``[libvirt]/live_migration_completion_timeout`` is restricted by
minimum 0 and will now raise a ValueError if the configuration option
value is less than minimum value.
Note if you configure Nova to have no timeout, post copy will never be
automatically triggered. None of this affects triggering post copy via
the force live-migration API, that continues to work in the same way.
upgrade:
- |
Config option ``[libvirt]/live_migration_progress_timeout`` was deprecated
in Ocata, and has now been removed.
Current logic in libvirt driver to auto trigger post-copy based on
progress information is removed as it has `proved impossible`__ to detect
when live-migration appears to be making little progress.
.. __: https://bugs.launchpad.net/nova/+bug/1644248