twitter/gizzard — pull request #92 by hyungoo (2012-03-14 02:08:49+00:00)
Title: Make nameserver reload operations lighter and faster

- Stop storing a snapshot of nameserver data in SqlShardManagerSource.
- In reload_updated_forwarding, build only the updated portion of the forwarding tree, instead of rebuilding the whole tree.
- NOTE: It still performs a shallow copy of the tree, one branch at a time.