https://github.com/openstack/swift/blob/master/swift/common/middleware/recon.py
1. How many unmounted (failed) drives there are in the cluster, and on which servers those are located
2. How many async pendings are present
3. Drive usage and balance
4. Load Average (for easy access later on*)
5. Memory Usage (for easy access later on*)
6. Checking ring md5sum’s
7. Logged replication stats
8. Connection stats (tbd)
9. Quarantine Statistics (a new pending addition)
WSGI filter
[pipeline:main] pipeline = recon object-server [filter:recon] use = egg:swift#recon recon_cache_path = /var/cache/swift