"MySQL server has gone away" when running deployment

[Ben Nemec]

This has been a recurring problem in my local environments. When I go to run a deployment on an undercloud that has been around for a while, it fails with the following output:

$ openstack overcloud deploy --templates --libvirt-type qemu -e ipv6-network-templates/network-environment.yaml -e ipv6-network-templates/network-isolation-absolute.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/disable-telemetry.yaml
Started Mistral Workflow tripleo.validations.v1.check_pre_deployment_validations. Execution ID: d2fb36e5-3ff3-44eb-ad30-a1731c83a4ef
{u'body': {u'exception': u'(pymysql.err.OperationalError) (2006, "MySQL server has gone away (error(32, \'Broken pipe\'))") [SQL: u\'INSERT INTO `Queues` (project, name, metadata) VALUES (%(project)s, %(name)s, %(metadata)s)\'] [parameters: {\'project\': u\'b89f3c42ba784e379e0c21e6187f2de2\', \'name\': u\'80c1fd8d-7eb1-407b-88f5-ff573c486b6b\', \'metadata\': bytearray(b\'{}\')}]', u'error': u'Unexpected error.'}, u'headers': {u'status': 500}, u'request': {u'action': u'queue_create', u'body': {u'queue_name': u'80c1fd8d-7eb1-407b-88f5-ff573c486b6b'}, u'api': u'v2', u'headers': {u'Client-ID': u'a426613b-b91c-4a16-91fa-164b435af8ed', u'X-Project-ID': u'b89f3c42ba784e379e0c21e6187f2de2'}}}

I find no evidence that the mysql server is actually misbehaving, and so far the solution has simply been to re-run the deploy command.

[Julie Pichon (jpichon)]

Bug 1691951 mentions both "Lost connection to MySQL server during query" and "MySQL server has gone away" in the comments, the related Zaqar patches may be of interest here too.

[Ben Nemec (bnemec)]

Ah, yes that looks like exactly what I'm seeing. I'll dupe this and watch the zaqar change to see if it fixes this.