Cost of a Synchronization Unit for Database Replication
2PC
- Vulnerable to faults at critical points.
- 3n unicasts overall, 1 forced disk per transaction per replica.
3PC
- Not always continues with quorum. Deprecated by E3PC [PDS95] Dolev+Keidar which always continues with quorum. In any case, too expensive – not in the game.
COReL by Keidar - VS based, global consistent persistent order.
- Quorum is non blocking.
- n multicasts overall, 1 forced disk per transaction per replica.
Our replication engine - EVS based.
- Vulnerable to all quorum replicas crashing together before any detects a problem.
- 1 safe multicast, 1/n forced disk per transaction per replica.