Purge Nova database of deleted instances
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Purge Nova database of deleted instances

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Article ID: 321765

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Updated On:

Products

VMware Integrated OpenStack

Issue/Introduction

Symptoms:

  • Upgrade of VMware Integrated Openstack (ie 5.1 to version 6.x or 7.x) takes a long time to upgrade Nova database
  • Large, heavily used environments when patching or upgrading regardless of version takes a long time.
  • Performance issues when interacting with the Nova service.



Environment

7.x

Cause

The Nova database contains records of deleted instances.  Cleaning this up before upgrade should speed up the time to upgrade the Nova database.

Resolution

Impact/Risks:
Warning: This procedure modifies the database. Ensure to take a backup of the deployment before proceeding.  See Backup and Restore.

  1. Backup Nova db.
osctl exec -ti mariadb-server-0 -- mysqldump --defaults-file=/etc/mysql/admin_user.cnf -R nova_cell0 > /tmp/nova_cell0_7.2.sql
osctl exec -it mariadb-server-0 -- mysqldump --defaults-file=/etc/mysql/admin_user.cnf -R nova_api > /tmp/nova_api_7.2.sql
osctl exec -ti mariadb-server-0 -- mysqldump --defaults-file=/etc/mysql/admin_user.cnf -R nova > /tmp/nova_7.2.sql
  1. Login to nova-api-osapi-xxxxx  pod.
osctl get pods | grep nova-api-osapi
osctl exec -it nova-api-osapi-687b5b8f99-ljptg bash
  1. Clean up  Nova database.

This will move deleted rows from production tables to shadow tables.  --verbose will print the results of the archive operation for any tables that were changed.

# nova-manage db archive_deleted_rows --verbose --until-complete --max_rows 10000
Archiving....complete
+------------------------------+-------------------------+
| Table                        | Number of Rows Archived |
+------------------------------+-------------------------+
| API_DB.instance_group_member | 0                       |
| API_DB.instance_mappings     | 22                      |
| API_DB.request_specs         | 22                      |
| block_device_mapping         | 22                      |
| instance_actions             | 53                      |
| instance_actions_events      | 53                      |
| instance_extra               | 22                      |
| instance_faults              | 1                       |
| instance_id_mappings         | 22                      |
| instance_info_caches         | 22                      |
| instance_metadata            | 1                       |
| instance_system_metadata     | 256                     |
| instances                    | 22                      |
| virtual_interfaces           | 22                      |
+------------------------------+-------------------------+

This will delete rows from shadow tables.  --verbose will cause information to be printed about purged records.

# nova-manage db purge --all --verbose
DB: Deleted 22 rows from shadow_block_device_mapping based on timestamp column (n/a)
DB: Deleted 53 rows from shadow_instance_actions based on timestamp column (n/a)
DB: Deleted 53 rows from shadow_instance_actions_events based on timestamp column (n/a)
DB: Deleted 22 rows from shadow_instance_extra based on timestamp column (n/a)
DB: Deleted 1 rows from shadow_instance_faults based on timestamp column (n/a)
DB: Deleted 22 rows from shadow_instance_id_mappings based on timestamp column (n/a)
DB: Deleted 22 rows from shadow_instance_info_caches based on timestamp column (n/a)
DB: Deleted 1 rows from shadow_instance_metadata based on timestamp column (n/a)
DB: Deleted 256 rows from shadow_instance_system_metadata based on timestamp column (n/a)
DB: Deleted 22 rows from shadow_instances based on timestamp column (n/a)
DB: Deleted 22 rows from shadow_virtual_interfaces based on timestamp column (n/a)

 Note: The command will take some time to execute especially with large amounts of records.

 

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