while populating the nova database cannot connect the database

[Shaswot Paudel]

su -s /bin/sh -c "nova-manage db sync" nova
ERROR: Could not access cell0.
Has the nova_api database been created?
Has the nova_cell0 database been created?
Has "nova-manage api_db sync" been run?
Has "nova-manage cell_v2 map_cell0" been run?
Is [api_database]/connection set in nova.conf?
Is the cell0 database connection URL correct?
Error: (pymysql.err.OperationalError) (2003, "Can't connect to MySQL server on 'sprl3@controller' ([Errno -2] Name or service not known)")
(Background on this error at: https://sqlalche.me/e/14/e3q8)

in /var/log/mysql/error.log

[Warning] Aborted connection 7608 to db: 'nova' user: 'nova' host: 'controller' (Got an error reading communication packets)

in /var/log/nova/nova-conductor.log

2024-04-22 21:24:41.214 49022 ERROR oslo_service.service FROM services
2024-04-22 21:24:41.214 49022 ERROR oslo_service.service WHERE services.deleted = %(deleted_1)s AND services.host = %(host_1)s AND services.`binary` = %(binary_1)s
2024-04-22 21:24:41.214 49022 ERROR oslo_service.service LIMIT %(param_1)s]
2024-04-22 21:24:41.214 49022 ERROR oslo_service.service [parameters: {'deleted_1': 0, 'host_1': 'sprl3', 'binary_1': 'nova-conductor', 'param_1': 1}]
2024-04-22 21:24:41.214 49022 ERROR oslo_service.service (Background on this error at: https://sqlalche.me/e/14/f405)
2024-04-22 21:24:41.214 49022 ERROR oslo_service.service

[Amit Uniyal (auniyal)]

please check here https://docs.openstack.org/nova/latest/admin/cells.html#configuring-a-new-deployment

if nova conf is okay, check the DB.