I'm not sure this is entirely fixed. I'm seeing very similar behavior running Percona XtraDB Cluster 5.5.39-36.0-55, and neutron 2014.2.1 (the migrations come from: python-neutron-2014.2.1-6.el7ost.noarch): Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 11549 Server version: 5.5.39-36.0-55 Percona XtraDB Cluster (GPL), Release rel36.0, Revision 824, WSREP version 25.11, wsrep_25.11.r4023 Copyright (c) 2009-2014 Percona LLC and/or its affiliates Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show tables; Empty set (0.00 sec) mysql> neutron-db-manage --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugin.ini current INFO [alembic.migration] Context impl MySQLImpl. INFO [alembic.migration] Will assume non-transactional DDL. Current revision for mysql://neutron:XXXXX@10.202.117.5/neutron: None neutron-db-manage --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugin.ini upgrade head INFO [alembic.migration] Context impl MySQLImpl. INFO [alembic.migration] Will assume non-transactional DDL. INFO [alembic.migration] Running upgrade None -> havana, havana_initial INFO [alembic.migration] Running upgrade havana -> e197124d4b9, add unique constraint to members INFO [alembic.migration] Running upgrade e197124d4b9 -> 1fcfc149aca4, Add a unique constraint on (agent_type, host) columns to prevent a race condition when an agent entry is 'upserted'. INFO [alembic.migration] Running upgrade 1fcfc149aca4 -> 50e86cb2637a, nsx_mappings INFO [alembic.migration] Running upgrade 50e86cb2637a -> 1421183d533f, NSX DHCP/metadata support INFO [alembic.migration] Running upgrade 1421183d533f -> 3d3cb89d84ee, nsx_switch_mappings INFO [alembic.migration] Running upgrade 3d3cb89d84ee -> 4ca36cfc898c, nsx_router_mappings INFO [alembic.migration] Running upgrade 4ca36cfc898c -> 27cc183af192, ml2_vnic_type INFO [alembic.migration] Running upgrade 27cc183af192 -> 50d5ba354c23, ml2 binding:vif_details INFO [alembic.migration] Running upgrade 50d5ba354c23 -> 157a5d299379, ml2 binding:profile INFO [alembic.migration] Running upgrade 157a5d299379 -> 3d2585038b95, VMware NSX rebranding INFO [alembic.migration] Running upgrade 3d2585038b95 -> abc88c33f74f, lb stats INFO [alembic.migration] Running upgrade abc88c33f74f -> 1b2580001654, nsx_sec_group_mapping INFO [alembic.migration] Running upgrade 1b2580001654 -> e766b19a3bb, nuage_initial INFO [alembic.migration] Running upgrade e766b19a3bb -> 2eeaf963a447, floatingip_status INFO [alembic.migration] Running upgrade 2eeaf963a447 -> 492a106273f8, Brocade ML2 Mech. Driver INFO [alembic.migration] Running upgrade 492a106273f8 -> 24c7ea5160d7, Cisco CSR VPNaaS INFO [alembic.migration] Running upgrade 24c7ea5160d7 -> 81c553f3776c, bsn_consistencyhashes INFO [alembic.migration] Running upgrade 81c553f3776c -> 117643811bca, nec: delete old ofc mapping tables INFO [alembic.migration] Running upgrade 117643811bca -> 19180cf98af6, nsx_gw_devices INFO [alembic.migration] Running upgrade 19180cf98af6 -> 33dd0a9fa487, embrane_lbaas_driver INFO [alembic.migration] Running upgrade 33dd0a9fa487 -> 2447ad0e9585, Add IPv6 Subnet properties INFO [alembic.migration] Running upgrade 2447ad0e9585 -> 538732fa21e1, NEC Rename quantum_id to neutron_id INFO [alembic.migration] Running upgrade 538732fa21e1 -> 5ac1c354a051, n1kv segment allocs for cisco n1kv plugin INFO [alembic.migration] Running upgrade 5ac1c354a051 -> icehouse, icehouse INFO [alembic.migration] Running upgrade icehouse -> 54f7549a0e5f, set_not_null_peer_address INFO [alembic.migration] Running upgrade 54f7549a0e5f -> 1e5dd1d09b22, set_not_null_fields_lb_stats INFO [alembic.migration] Running upgrade 1e5dd1d09b22 -> b65aa907aec, set_length_of_protocol_field INFO [alembic.migration] Running upgrade b65aa907aec -> 33c3db036fe4, set_length_of_description_field_metering INFO [alembic.migration] Running upgrade 33c3db036fe4 -> 4eca4a84f08a, Remove ML2 Cisco Credentials DB INFO [alembic.migration] Running upgrade 4eca4a84f08a -> d06e871c0d5, set_admin_state_up_not_null_ml2 INFO [alembic.migration] Running upgrade d06e871c0d5 -> 6be312499f9, set_not_null_vlan_id_cisco INFO [alembic.migration] Running upgrade 6be312499f9 -> 1b837a7125a9, Cisco APIC Mechanism Driver INFO [alembic.migration] Running upgrade 1b837a7125a9 -> 10cd28e692e9, nuage_extraroute INFO [alembic.migration] Running upgrade 10cd28e692e9 -> 2db5203cb7a9, nuage_floatingip INFO [alembic.migration] Running upgrade 2db5203cb7a9 -> 5446f2a45467, set_server_default INFO [alembic.migration] Running upgrade 5446f2a45467 -> db_healing, Include all tables and make migrations unconditional. INFO [alembic.migration] Context impl MySQLImpl. INFO [alembic.migration] Will assume non-transactional DDL. INFO [alembic.autogenerate.compare] Detected server default on column 'cisco_ml2_apic_epgs.provider' INFO [alembic.autogenerate.compare] Detected removed index 'cisco_n1kv_vlan_allocations_ibfk_1' on 'cisco_n1kv_vlan_allocations' INFO [alembic.autogenerate.compare] Detected server default on column 'cisco_n1kv_vxlan_allocations.allocated' INFO [alembic.autogenerate.compare] Detected removed index 'cisco_n1kv_vxlan_allocations_ibfk_1' on 'cisco_n1kv_vxlan_allocations' INFO [alembic.autogenerate.compare] Detected removed index 'embrane_pool_port_ibfk_2' on 'embrane_pool_port' INFO [alembic.autogenerate.compare] Detected removed index 'firewall_rules_ibfk_1' on 'firewall_rules' INFO [alembic.autogenerate.compare] Detected removed index 'firewalls_ibfk_1' on 'firewalls' INFO [alembic.autogenerate.compare] Detected server default on column 'meteringlabelrules.excluded' INFO [alembic.autogenerate.compare] Detected server default on column 'ml2_port_bindings.host' INFO [alembic.autogenerate.compare] Detected added column 'nuage_routerroutes_mapping.destination' INFO [alembic.autogenerate.compare] Detected added column 'nuage_routerroutes_mapping.nexthop' INFO [alembic.autogenerate.compare] Detected server default on column 'poolmonitorassociations.status' INFO [alembic.autogenerate.compare] Detected added index 'ix_quotas_tenant_id' on '['tenant_id']' INFO [alembic.autogenerate.compare] Detected NULL on column 'tz_network_bindings.phy_uuid' INFO [alembic.autogenerate.compare] Detected NULL on column 'tz_network_bindings.vlan_id' INFO [neutron.db.migration.alembic_migrations.heal_script] Detected removed foreign key u'nuage_floatingip_pool_mapping_ibfk_2' on table u'nuage_floatingip_pool_mapping' Traceback (most recent call last): File "/usr/bin/neutron-db-manage", line 10, in sys.exit(main()) File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 173, in main CONF.command.func(config, CONF.command.name) File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 83, in do_upgrade_downgrade do_alembic_command(config, cmd, revision, sql=CONF.command.sql) File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 61, in do_alembic_command getattr(alembic_command, cmd)(config, *args, **kwargs) File "/usr/lib/python2.7/site-packages/alembic/command.py", line 125, in upgrade script.run_env() File "/usr/lib/python2.7/site-packages/alembic/script.py", line 203, in run_env util.load_python_file(self.dir, 'env.py') File "/usr/lib/python2.7/site-packages/alembic/util.py", line 212, in load_python_file module = load_module_py(module_id, path) File "/usr/lib/python2.7/site-packages/alembic/compat.py", line 58, in load_module_py mod = imp.load_source(module_id, path, fp) File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/env.py", line 108, in run_migrations_online() File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/env.py", line 100, in run_migrations_online context.run_migrations() File "", line 7, in run_migrations File "/usr/lib/python2.7/site-packages/alembic/environment.py", line 688, in run_migrations self.get_context().run_migrations(**kw) File "/usr/lib/python2.7/site-packages/alembic/migration.py", line 258, in run_migrations change(**kw) File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/versions/1d6ee1ae5da5_db_healing.py", line 32, in upgrade heal_script.heal() File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/heal_script.py", line 80, in heal execute_alembic_command(el) File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/heal_script.py", line 92, in execute_alembic_command METHODS[command[0]](*command[1:]) File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/heal_script.py", line 175, in add_column op.add_column(table_name, column.copy(), schema=schema) File "", line 7, in add_column File "/usr/lib/python2.7/site-packages/alembic/operations.py", line 428, in add_column schema=schema File "/usr/lib/python2.7/site-packages/alembic/ddl/impl.py", line 127, in add_column self._exec(base.AddColumn(table_name, column, schema=schema)) File "/usr/lib/python2.7/site-packages/alembic/ddl/impl.py", line 76, in _exec conn.execute(construct, *multiparams, **params) File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 729, in execute return meth(self, multiparams, params) File "/usr/lib64/python2.7/site-packages/sqlalchemy/sql/ddl.py", line 69, in _execute_on_connection return connection._execute_ddl(self, multiparams, params) File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 783, in _execute_ddl compiled File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 958, in _execute_context context) File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1156, in _handle_dbapi_exception util.raise_from_cause(newraise, exc_info) File "/usr/lib64/python2.7/site-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause reraise(type(exception), exception, tb=exc_tb) File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 951, in _execute_context context) File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/default.py", line 436, in do_execute cursor.execute(statement, parameters) File "/usr/lib64/python2.7/site-packages/MySQLdb/cursors.py", line 174, in execute self.errorhandler(self, exc, value) File "/usr/lib64/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler raise errorclass, errorvalue oslo.db.exception.DBConnectionError: (OperationalError) (2013, 'Lost connection to MySQL server during query') 'ALTER TABLE nuage_routerroutes_mapping ADD COLUMN destination VARCHAR(64) NOT NULL' () The reason the connection to the DB is being lost is because it's crashing every node in the cluster. mysql neutron ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (111) systemctl status mysql mysql.service - LSB: start and stop MySQL (Percona XtraDB Cluster) Loaded: loaded (/etc/rc.d/init.d/mysql) Active: failed (Result: exit-code) since Thu 2015-02-19 13:45:23 EST; 24min ago Process: 18961 ExecStart=/etc/rc.d/init.d/mysql start (code=exited, status=1/FAILURE) I am able to manually go to havana and/or icehouse, but as soon as I try to make the last step to juno or head, I always get the same error. This happens with both a new DB or when attempting to upgrade an existing one.