Lecture 4: Groups
Terms you should know
Paul Krzyzanowski
September 27, 2021
Group communication
- Uicast
- Anycast
- Broadcast
- Multicast
- Multicast groups
- Open vs. closed groups
- Peer vs. hierarchical communication
- Coordinator
- Unreliable multicast
- Reliable multicast
- Atomic multicast
- Optimizations:
- Pipelining
- Cumulative acknowledgments
- Piggybacked acknowledgments
- Negative acknowldgements
- Message receipt vs. delivery
- Hold-back queue
- Global time ordering
- Total ordering
- Causal ordering, partial ordering
- Sync ordering
- Single source FIFO ordering
- Unordered multicast
- Totally sequenced message IDs
- Precedence vector (what it does, don’t memorize the algorithm)
- Barrier
IP Multicast
- IP multicast address (purpose)
- Host group
- Properties
- IGMP: Internet Group Management Protocol
- Membership query
- Membership report
- Leave group
- IGMP vs. PIM (Protocol Independent Multicast)
- PIM-DM - Dense Mode
- PIM-SM - Sparse Mode
- Rendezvous Point (RP)
Virtual Synchrony
- State machine replication (the concept)
- Stale state
- Process group
- Synchronous vs. asynchronous networks
- Two armies problem
- Group view
- View change
- Group Management Service (GMS)
- Stable vs. unstable messages
- Flush message
- State transfer