When user requests the record registration request continuously,
sometimes designate hits DBDeadLock resuting into 500 InternalServerError.
We get below error:
2019-02-21 21:30:39.925 49752 ERROR designate.api.middleware RemoteError:
Remote error: DBDeadlock (pymysql.err.InternalError)
(1213, u'Deadlock found when trying to get lock; try restarting transaction')
[SQL: u'UPDATE records SET version=(records.version + %(version_1)s),
updated_at=%(updated_at)s, data=%(data)s, hash=%(hash)s, status=%(status)s,
action=%(action)s, serial=%(serial)s WHERE records.id = %(id_1)s']
[parameters: {'status': 'PENDING', 'hash': '39795ee18c6e3c9ad1c0190c6a3d8d4f',
'updated_at': datetime.datetime(2019, 2, 21, 12, 30, 39, 909846), u'version_1': 1,
u'id_1': '7a655eeda4d446cdaa81caf19ab55fcc', 'action': 'UPDATE',
'serial': 1550752338,
'data': u'ns2.example.jp. domain.example.com. 1550752338 3552 600 86400 3600'}]
In the process of record registeration, designate first tried to update
the reocrd and then update the zone status.
Updating the zone_status and registering the record process[1] and after synced
update record_status and zone_status process[2] are in reverse order. So If user
request the registering record many time and same time, Designate will get the
DBDeadLock, when these processes run the same time.
We observed that changing the order of the operations solves this issue.
[1] https://github.com/openstack/designate/blob/master/designate/central/service.py#L1292-L1320
[2] https://github.com/openstack/designate/blob/master/designate/central/service.py#L2310-L2322
1. transaction [1]-1 updating zone status process <- run ---> table_name-zone
2. transaction [2]-1 updating record status process <- run ---> table_name-record
3. transaction [1]-2 registering record process <- run and wait ---> table_name-record
4. transaction [2]-2 updating zone process <-deadlock! ---> table_name-zone
Change-Id: Icd6e690ac84a2fe0db0f4a8a513de47f7916f5ea
Related-Bug: #1785459
f828654a3d