
Servers. Replicated server cluster
Each server stores complete state in memory
Updates are also stored in persistent log
Persistent snapshot done when updates accumulate
Atomic communication protocol
All updates pass through leader server
Leader collects majority quorum for each update
Leader election triggered in case of cluster failure
Clients.
Provided with a list of servers to use
Connected to a single server at a time
Watch state and ordering defined within client session
Connection failure handled by switching to another server