Lecture 8: Zookeeper

• The history is linearizable

• not linearizable - cycle in the graph

• Zookeeper layer
  • ZAB layer
• many clients
• more servers -> slower
• allow client to send any read only request to any replica

• log

• guarantees
  • linearizable writes
  • cheap read
  • want fresh data
    • can send a sync operation

• write order

• read order?
  • exist("ready")

• if it ever exists, PLEASE send me a notification
  • at the correct point in the log to the client's reads!