This upstream patch has been addressed in Liberty but has not yet been

addressed in Kilo.

commit c0d0e5ccf62f45498f084ed59e776c3b370e9137

Author: jichenjc <[email protected]>

Date:   Mon Mar 23 00:36:43 2015 +0800

    Handle MessageTimeout to MigrationPreCheckError

    There are a few checks before live-migration, if any of the

    check failed, the live-migration can't be done. However

    during _call_livem_checks_on_host check, because it's a

    RPC call ,so it might result in a MessageTimeout exception.

    If this occurs, we should safely revert its state,

    since no real opperation occured.

    This patch translates the MessageTimeout to

    MigrationPreCheckError and leverage existing MigrationPreCheckError

    processing to revert instance to normal state instead of error

    Closes-Bug: 1435633

    Change-Id: I8b484abb6650e14e2d225ca5e476d1fa7a6ee990

--- nova-2015.1.2/nova/conductor/tasks/live_migrate.py.~1~	2015-10-13 07:52:44.000000000 -0700

+++ nova-2015.1.2/nova/conductor/tasks/live_migrate.py	2016-02-10 23:52:06.321170852 -0800

@@ -12,6 +12,7 @@

 from oslo_config import cfg

 from oslo_log import log as logging

+import oslo_messaging as messaging

 from nova.compute import power_state

 from nova.compute import rpcapi as compute_rpcapi

@@ -140,9 +141,14 @@ class LiveMigrationTask(object):

             raise exception.DestinationHypervisorTooOld()

     def _call_livem_checks_on_host(self, destination):

-        self.migrate_data = self.compute_rpcapi.\

-            check_can_live_migrate_destination(self.context, self.instance,

-                destination, self.block_migration, self.disk_over_commit)

+        try:

+            self.migrate_data = self.compute_rpcapi.\

+                check_can_live_migrate_destination(self.context, self.instance,

+                    destination, self.block_migration, self.disk_over_commit)

+        except messaging.MessagingTimeout:

+            msg = _("Timeout while checking if we can live migrate to host: "

+                    "%s") % destination

+            raise exception.MigrationPreCheckError(msg)

     def _find_destination(self):

         # TODO(johngarbutt) this retry loop should be shared

--- nova-2015.1.2/nova/tests/unit/conductor/tasks/test_live_migrate.py.~1~	2015-10-13 07:52:44.000000000 -0700

+++ nova-2015.1.2/nova/tests/unit/conductor/tasks/test_live_migrate.py	2016-02-10 23:52:46.817923384 -0800

@@ -11,6 +11,7 @@

 #    under the License.

 from mox3 import mox

+import oslo_messaging as messaging

 from nova.compute import power_state

 from nova.compute import utils as compute_utils

@@ -401,5 +402,12 @@ class LiveMigrationTaskTestCase(test.NoD

         self.mox.ReplayAll()

         self.assertRaises(exception.NoValidHost, self.task._find_destination)

+    def test_call_livem_checks_on_host(self):

+        with mock.patch.object(self.task.compute_rpcapi,

+            'check_can_live_migrate_destination',

+            side_effect=messaging.MessagingTimeout):

+            self.assertRaises(exception.MigrationPreCheckError,

+                self.task._call_livem_checks_on_host, {})

+

     def test_not_implemented_rollback(self):

         self.assertRaises(NotImplementedError, self.task.rollback)