| 2016-03-02 16:14:11 |
Pawel Koniszewski |
description |
All block live migrations are broken when I want nova to calculate live migration type by specifying {'block_migration': 'auto'} in request body. This happens because block_migration and migrate_data.block_migration flags do not have the same value.
In conductor live migrate task we call checks on destination and source that builds up migrate_data in driver and sends them back to conductor:
https://github.com/openstack/nova/blob/master/nova/conductor/tasks/live_migrate.py#L156
Here we calculate block migration, this is fine:
https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L5554
Then it goes back to conductor and we call compute manager sending both flags - block_migration and migrate_data.block_migration - but we never changed value of block_migration to match migrate_data.block_migration:
https://github.com/openstack/nova/blob/master/nova/conductor/tasks/live_migrate.py#L68
Because down in compute manager (and in drivers) we use both flags that have different values (here block_migration=None, migrate_data.block_migration=True), e.g. at this point block_migration=None:
https://github.com/openstack/nova/blob/master/nova/compute/manager.py#L5196
We break all block live migrations with:
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line 457, in fire_timers
timer()
File "/usr/local/lib/python2.7/dist-packages/eventlet/hubs/timer.py", line 58, in __call__
cb(*args, **kw)
File "/usr/local/lib/python2.7/dist-packages/eventlet/event.py", line 168, in _do_send
waiter.switch(result)
File "/usr/local/lib/python2.7/dist-packages/eventlet/greenthread.py", line 214, in main
result = function(*args, **kwargs)
File "/opt/stack/nova/nova/utils.py", line 1160, in context_wrapper
return func(*args, **kwargs)
File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6095, in _live_migration_operation
instance=instance)
File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
self.force_reraise()
File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
six.reraise(self.type_, self.value, self.tb)
File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6063, in _live_migration_operation
CONF.libvirt.live_migration_bandwidth)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 186, in doit
result = proxy_call(self._autowrap, f, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 144, in proxy_call
rv = execute(f, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 125, in execute
six.reraise(c, e, tb)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 83, in tworker
rv = meth(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/libvirt.py", line 1825, in migrateToURI2
if ret == -1: raise libvirtError ('virDomainMigrateToURI2() failed', dom=self)
libvirtError: Cannot access storage file '/opt/stack/data/nova/instances/572ad149-b7c5-4b77-85b5-34c1d2d37fcf/disk' (as uid:110, gid:116): No such file or directory
Fast workaround is making sure at compute manager level that block_migration == migrate_data.block_migration, but really we should cleanup all this mess and send only one flag, because it is error-prone and hard to maintain. |
All block live migrations are broken when I want nova to calculate live migration type by specifying {'block_migration': 'auto'} in request body. This happens because block_migration and migrate_data.block_migration flags do not have the same value.
In conductor live migrate task we call checks on destination and source that builds up migrate_data in driver and sends them back to conductor:
https://github.com/openstack/nova/blob/master/nova/conductor/tasks/live_migrate.py#L156
Here we calculate block migration, this is fine:
https://github.com/openstack/nova/blob/master/nova/virt/libvirt/driver.py#L5554
Then it goes back to conductor and we call compute manager sending both flags - block_migration and migrate_data.block_migration - but we never change value of block_migration to match migrate_data.block_migration:
https://github.com/openstack/nova/blob/master/nova/conductor/tasks/live_migrate.py#L68
Because down in compute manager (and in drivers) we use both flags that have different values (here block_migration=None, migrate_data.block_migration=True), e.g. at this point block_migration=None:
https://github.com/openstack/nova/blob/master/nova/compute/manager.py#L5196
We break all block live migrations with:
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line 457, in fire_timers
timer()
File "/usr/local/lib/python2.7/dist-packages/eventlet/hubs/timer.py", line 58, in __call__
cb(*args, **kw)
File "/usr/local/lib/python2.7/dist-packages/eventlet/event.py", line 168, in _do_send
waiter.switch(result)
File "/usr/local/lib/python2.7/dist-packages/eventlet/greenthread.py", line 214, in main
result = function(*args, **kwargs)
File "/opt/stack/nova/nova/utils.py", line 1160, in context_wrapper
return func(*args, **kwargs)
File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6095, in _live_migration_operation
instance=instance)
File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 220, in __exit__
self.force_reraise()
File "/usr/local/lib/python2.7/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise
six.reraise(self.type_, self.value, self.tb)
File "/opt/stack/nova/nova/virt/libvirt/driver.py", line 6063, in _live_migration_operation
CONF.libvirt.live_migration_bandwidth)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 186, in doit
result = proxy_call(self._autowrap, f, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 144, in proxy_call
rv = execute(f, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 125, in execute
six.reraise(c, e, tb)
File "/usr/local/lib/python2.7/dist-packages/eventlet/tpool.py", line 83, in tworker
rv = meth(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/libvirt.py", line 1825, in migrateToURI2
if ret == -1: raise libvirtError ('virDomainMigrateToURI2() failed', dom=self)
libvirtError: Cannot access storage file '/opt/stack/data/nova/instances/572ad149-b7c5-4b77-85b5-34c1d2d37fcf/disk' (as uid:110, gid:116): No such file or directory
Fast workaround is making sure at compute manager level that block_migration == migrate_data.block_migration, but really we should cleanup all this mess and send only one flag, because it is error-prone and hard to maintain. |
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