Cloned from launchpad blueprint https://blueprints.launchpad.net/cinder/+spec/db-archiving.

Description:

In Nova (Grizzly) we added new feature DB Archiving. 

The problem: 
We actually don't delete rows from db, we mark it only as deleted (we have special column).
So the DB is growing and growing, so this causes problem with performance.

The solution:
Create shadow tables and copy "deleted" rows from main to shadow table. 

Steps to implement:
1) sync utils for work with shadow table (create, check methods)
2) add db migration, that will create all shadow tables
3) write tests for shadowing (for example checking that all shadow tables are up-to-date)
4) add utils to work with shadowing (periodic task, manager method)

 

Specification URL (additional information):

None