Send as much DB traffic as possible from periodic tasks to DB slaves

I would have given a higher priority than Low to this normally, but it's just that it's a new blueprint toward the end of the cycle. I don't want to block if this doesn't make it. If this spills into Icehouse, I'll up the priority. --russellb

Gerrit topic: https://review.openstack.org/#q,topic:bp/periodic-tasks-to-db-slave,n,z

Addressed by: https://review.openstack.org/38872
    Allow _sync_power_states periodic task to hit slave DB

I think it's fine if the above patch lands in Havana. Since this blueprint covers much more than this first periodic task, I updated it for Icehouse, since that's when the vast majority of the changes will end up. --russellb

Addressed by: https://review.openstack.org/57358
    Allow all instance polling periodic tasks to hit db slave

Addressed by: https://review.openstack.org/57360
    Periodic task _poll_unconfirmed_resize can now use slave db

Addressed by: https://review.openstack.org/57372
    WIP Periodic task _heal_instance_info_cache can now use slave db

Addressed by: https://review.openstack.org/60992
    Allow _check_instance_build_time to hit db slave

Addressed by: https://review.openstack.org/61009
    Fix bug #1259383

Addressed by: https://review.openstack.org/61011
    Allow run_image_cache_manager_pass to hit db slave

I'm going to wait on Nikola Dipanov's object implementation of BDMS before I slaveify _cleanup_running_deleted_instances. The non-object way is gross, so I'd rather wait
for it to be pretty and workable. --geekinutah

Addressed by: https://review.openstack.org/72797
    Task cleanup_running_deleted_instances can now use slave

We're passed the deadline for blueprint code to be proposed for Icehouse, but I think this one should get an exception since most of it has been completed. Let's leave this targeted to Icehouse for now. --russellb

I removed update_available_resource task because there is more work to be done in the Service object that will likely take a while. I'll revisit this in Juno. As it stands this bp should just need code review and fixups. --geekinutah

Gerrit topic: https://review.openstack.org/#q,topic:bp/periodic-tasks-to-db-slave-cleanup_running_deleted_instances,n,z

patch moved to juno:
===========================
https://review.openstack.org/#/c/72797/
(Note: stuck behind BDM changes)

Apologies, this missed the deadline for Feature Freeze. Marking this one as Implemented, so please open a new blueprint for the remaining patches. Please rebase patches as soon as Juno opens, and we will try to get this in during that period. --johnthetubaguy (5th March 2014)

This was subsequently merged as BDM got FFE. -geekinutah

Work items:
slaveify _check_instance_build_time: DONE
slaveify _heal_instance_info_cache: DONE
slaveify _poll_rebooting_instances: DONE
slaveify _poll_rescued_instances: DONE
slaveify _poll_unconfirmed_resizes: DONE
slaveify _poll_shelved_instances: DONE
slaveify _poll_bandwidth_usage: DONE
slaveify _sync_power_states: DONE
slaveify _reclaim_queued_deletes: DONE
slaveify _cleanup_running_deleted_instances: DONE
slaveify _run_image_cache_manager_pass: DONE