Support mongodb point in time recovery

Trove and Point-in-time recovery

OpenStack DBaaS Trove able to perform restoring instance (whole new instance, from scratch) from previously stored backup in remote storage (OpenStack Swift, Amazon AWS S3, etc). From administration/regular user perspective Trove should be able to perform point in time recovery. Basically its almost the same as restoring new instance, but the difference between restore(in terms of Trove) and recovery is huge.
Restore gives an ability to spin-up new instance from backup (as mentioned earlier), but the Recovery gives an ability to restore already running instance from backup.
Trove core ReST API and Point-in-Time Recovery/Restore flow

ReST routes

HTTP method
Routes

POST
{tenant_id}/instances/{instance_id}/recover

or

{tenant_id}/instances/{instance_id}/restore
Request body

“recovery”: {
    “instance”: UUID,
    “backup”: UUID,
}
Response object

“recovery”: {
    “id”: “instance_id”,
    “name”: “instance_name”,
    “status”: “BUILDING”,
    “datastore”: “mysql”,
    “recovered_from_backup”: “backup_id”,
    “point_in_time”: “2011-01-22T13:25:27-06:00”,
}

Trove taskmanager RPC API and Point-in-Time Recovery/Restore flow

RPC message
RPC method
Method parameters
do_instance_recovery
instance_id
backup_id
RPC message type
    CAST with poll until instance reach ACTIVE status.
Trove guestagent RPC API and Point-in-Time Recovery/Restore flow

RPC message
RPC method
Method parameters

do_recovery
        backup_info: {
                      'id': backup_id,
                      ‘location': location,
                      ’type': backup_type,
                     'checksum': checksum,
        }
RPC message type
    CAST

Method implementation

No new code. Re-used restore functionality.

Proposed implementation for Trove and for Python-troveclient

Trove: [1]
Python-troveclient: [2]

Useful links
[1] https://review.openstack.org/#/c/77222/
[2] https://review.openstack.org/#/c/77223/

WIKI page https://wiki.openstack.org/wiki/Trove/PointInTimeRecovery