Slide 2 P. Hunt, M Konar, F. Junqueira, B. Reed Presented by
David Stein for ECE598YL SP12 Slide 3 Versatile distributed
coordination system Simple primitives Application developers use
API to implement higher-level coordination primitives Wait-free
non-blocking design Strong ordering guarantees Designed for
read-intensive workload Slide 4 Hierarchical, filesystem-like
design znodes Regular (persistent) Ephemeral (session) Supports
sequential naming of nodes Nodes contain values Sessions Slide 5
Slide 6 create(path, data, flags) delete(path, version)
exists(path, watch) getData(path, watch) setData(path, data,
version) getChildren(path, watch) sync(path) Slide 7 Linearizable
writes FIFO client order Liveness Durability Slide 8 Data is
replicated on every server Reads are serviced immediately Write
requests are forwarded to the leader Transforms requests from
client into idempotent transaction records Zab is used to push
idempotent transaction records to the replicated database (stored
with the followers) Strong order guarantees (uses TCP) Slide 9
Slide 10 Local replicas will never diverge But any point in time,
some local servers may have applied more transactions than others
Failure recovery Periodic snapshots are kept at each replica
Idempotent transaction records can be received in any order to
rebuild the state Slide 11 Configuration Management Rendezvous
Group Membership Locks Slide 12 Yahoo! Fetching Service Part of
Yahoo! crawler for search engine Uses ZooKeeper to manage
configuration metadata and leader election. Katta Yahoo! Message
Broker Publish-subscribe system Slide 13 Slide 14 Slide 15 Slide 16
Chubby Boxwood ISIS Paxos Sinfonia Dynamo Slide 17
