Reviewed: https://review.openstack.org/551302 Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=b626c0dc7b113365002e743e6de2aeb40121fc81 Submitter: Zuul Branch: master
commit b626c0dc7b113365002e743e6de2aeb40121fc81 Author: Matthew Booth <mbo...@redhat.com> Date: Fri Mar 9 14:41:49 2018 +0000 Avoid redundant initialize_connection on source post live migration During live migration we update bdm.connection_info for attached volumes in pre_live_migration to reflect the new connection on the destination node. This means that after migration completes the BDM no longer has a reference to the original connection_info to do the detach on the source host. To address this, change I3dfb75eb added a second call to initialize_connection on the source host to re-fetch the source host connection_info before calling disconnect. Unfortunately the cinder driver interface does not strictly require that multiple calls to initialize_connection will return consistent results. Although they normally do in practice, there is at least one cinder driver (delliscsi) which doesn't. This results in a failure to disconnect on the source host post migration. This change avoids the issue entirely by fetching the BDMs prior to modification on the destination node. As well as working round this specific issue, it also avoids a redundant cinder call in all cases. Note that this massively simplifies post_live_migration in the libvirt driver. The complexity removed was concerned with reconstructing the original connection_info. This required considering the cinder v2 and v3 use cases, and reconstructing the multipath_id which was written to connection_info by the libvirt fibrechannel volume connector on connection. These things are not necessary when we just use the original data unmodified. Other drivers affected are Xenapi and HyperV. Xenapi doesn't touch volumes in post_live_migration, so is unaffected. HyperV did not previously account for differences in connection_info between source and destination, so was likely previously broken. This change should fix it. Closes-Bug: #1754716 Closes-Bug: #1814245 Change-Id: I0390c9ff51f49b063f736ca6ef868a4fa782ede5 ** Changed in: nova Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1754716 Title: Disconnect volume on live migration source fails if initialize_connection doesn't return identical output Status in OpenStack Compute (nova): Fix Released Bug description: During live migration we update bdm.connection_info for attached volumes in pre_live_migration to reflect the new connection on the destination node. This means that after migration completes we no longer have a reference to the original connection_info to do the detach on the source host, so we have to re-fetch it with a second call to initialize_connection before calling disconnect. Unfortunately the cinder driver interface does not strictly require that multiple calls to initialize_connection will return consistent results. Although they normally do in practice, there is at least one cinder driver (delliscsi) which doesn't. This results in a failure to disconnect on the source host post migration. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1754716/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp