Upgrade PostgreSQL Flexible Server for eFormidling (TT02 and Prod) to Version 16

[ootneim]

Description:
We need to upgrade the PostgreSQL Flexible Server instances used by eFormidling in both TT02 (test) and Production environments to PostgreSQL version 16. This upgrade aims to leverage the performance improvements, security patches, and new features available in PostgreSQL 16.

Environments Affected:

• TT02 (Test)
• Production

Action Plan:

1. Backup:
   • Ensure that full backups are in place and have been recently verified.
   • Restore a backup (altinn-eformidling-db-tt02-15-pgflex, altinn-eformidling-db-prod-15-pgflex)
2. Testing in TT02:
   • Perform the upgrade in TT02 first to verify compatibility and identify any potential issues.
   • Run smoke tests and integration tests to confirm that the eFormidling application operates correctly with PostgreSQL 16.
3. Upgrade in Production:
   • Schedule a maintenance window for the upgrade.
   • Notify stakeholders and users of the expected downtime or service impact.
   • Perform the upgrade and monitor for any post-upgrade issues.
4. Post-Upgrade Validation:
   • Run validation checks on both TT02 and Production environments.
   • Confirm that all eFormidling functions work as expected and that there are no database performance issues.

Impact:
Upgrading to PostgreSQL 16 is expected to improve database performance and security for eFormidling. However, there may be temporary downtime during the upgrade process, so this should be carefully planned and communicated.

Additional Notes:

• Ensure that all database extensions and custom configurations are compatible with PostgreSQL 16.
• Reference the PostgreSQL 16 Release Notes for any breaking changes or deprecations.

Upgrade:

• [x] altinn-eformidling-db-tt02-pgflex
• [ ] altinn-eformidling-db-prod-pgflex