OSTF test "Instance live migration" failed

[Georgy Dyuldin]

Detailed bug description:
 After deploy MOS 9.1 snapshot #323 OSFT test "Instance live migration" failed with "Creating instance using the new security group has failed. Please refer to OpenStack logs for more details."

Steps to reproduce:
 1. Deploy MOS 9.1 snapshot #323 with 3 controller+mongo, 2 computes+ceph, 1 ironic node (DVR) with fuel-qa system-test based template.
 2. Run OSTF functional tests after deploy

Expected results:
 All tests should pass

Actual result:
 Test "Instance live migration" failed

Reproducibility:
 Sometimes

Description of the environment:
- Storage: Ceph (ephemeral-ceph, image-ceph, rados-ceph)
- Network model: Vlan + DVR

Additional information:
 Same configuration, but without ceph pass OSTF. On previous builds fails another OSFT tests. After reverting last snapshot (which was made right after OSTF fail) this test pass.

[Roman Podoliaka (rpodolyaka)]

MySQL was down at the moment when OSTF made a request to compute API:

2016-09-29 10:17:47.202 31319 ERROR nova.api.openstack.extensions DBConnectionError: (_mysql_exceptions.OperationalError) (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 0") [SQL: u'SELECT 1']
2016-09-29 10:17:47.202 31319 ERROR nova.api.openstack.extensions
2016-09-29 10:17:47.231 31319 INFO nova.api.openstack.wsgi [req-5b2ab66b-c59c-41b1-ae80-bb29e3e5b87b f770103c049444a0b96607c84cfa64f9 9e1b11b0f43847e9af03901fb9d53cdb - - -] HTTP exception thrown: Unexpected API Error. Please report this at http://bugs.launchpad.net/nova/ and attach the Nova API log if possible.

<27>Sep 29 10:17:38 node-1 ocf-mysql-wss: ERROR: p_mysqld: check_if_galera_pc(): But I'm running a new cluster, PID:31273, this is a split-brain!
<27>Sep 29 10:17:38 node-1 ocf-mysql-wss: ERROR: p_mysqld: mysql_monitor(): I'm a master, and my GTID: ea7f8f4a-8625-11e6-972b-07e3d90a05af:7755, which was not expected
<27>Sep 29 10:17:44 node-1 ocf-mysql-wss: ERROR: p_mysqld: mysql_status(): PIDFile /var/run/resource-agents/mysql-wss/mysql-wss.pid of MySQL server not found. Sleeping for 2 seconds. 0 retries left
<27>Sep 29 10:17:46 node-1 ocf-mysql-wss: ERROR: p_mysqld: mysql_status(): MySQL is not running
<129>Sep 29 10:17:50 node-1 haproxy[16504]: Server mysqld/node-1 is DOWN, reason: Layer7 wrong status, code: 503, info: "Service Unavailable", check duration: 17ms. 0 active and 2 backup servers left. Running on backup. 93 sessions active, 0 requeued, 0 remaining in queue.
(END)

No OOM entries in logs. I think it's the very issue we saw in https://bugs.launchpad.net/fuel/+bug/1620268