ceph/ceph — pull request #1139 by liewegas (2014-01-25 00:45:27+00:00)
Title: osd: basic cache tier agent

This branch includes a basic cache tier agent. It isn't doing anything
smart about object temperature (how frequently it is accessed) but it is
reasonably smart about how recently objects were accessed, and it puts the
basic infrastruture in place.

Missing components:

- better prioritization of the agent work thread. not sure what the best
approach here is.
- some temperature smarts. i think we need to define another policy paramter
to control how the agent weighs atime vs temp.. and i think we also need to
add a creation timestamp in object_info_t to make that work.
- only a single thread initiating agent work.