| 2017-09-18 09:00:41 |
Ebbex |
description |
During an upgrade, you'll already have a entry in the nova.services table for 'nova-osapi_compute'.
The new wsgi app has NAME='osapi_compute' and first queries for this name, which yields 0 rows.
Then since there's no entry it decides to create a new entry with INSERT where it appends 'nova-' to this 'name'. Problem is there's already an entry for 'nova-osapi_compute', so now the insert fails because of duplicate entries.
So NAME has to be changed, or append 'nova-' on both queries.
Also the queries
SELECT
if exists UPDATE
if not exists INSERT
Could really just boil down to
UPDATE
if fail INSERT
This way it's atomic aswell. |
Before an upgrade, we have these type of entries in the db.
MariaDB [nova]> SELECT id, host, `binary`, deleted, version FROM services;
+----+--------------+--------------------+---------+---------+
| id | host | binary | deleted | version |
+----+--------------+--------------------+---------+---------+
| 5 | r1-n-os-api | nova-osapi_compute | 0 | 16 |
| 21 | r1-n-m-api | nova-metadata | 0 | 16 |
The wsgi files we run basically boil down to something like
NAME=metadata
return wsgi_app.init_application(NAME)
In the wsgi_app.py we see this function
service_ref = objects.Service.get_by_host_and_binary(ctxt, host, name)
Which results in a really big query, which again comes down to
SELECT host, `binary` FROM services
WHERE host = 'r1-n-m-api' AND `binary` == 'metadata'
No results. service_ref is set to None. Carry on.
if service_ref:
#Nope.
else:
try:
...
service_obj.host = host
service_obj.binary = 'nova-%s' % name
service_obj.create()
Which results in a INSERT statement something like this;
INSERT INTO services(host, `binary`, report_count, disabled, deleted, version)
VALUES ('r1-n-m-api', 'nova-metadata', 0, 0, 0, 22)
ERROR 1062 (23000): Duplicate entry 'r1-n-m-api-nova-metadata-0' for key 'uniq_services0host0binary0deleted' |
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