Quorum systems ensure consistency through overlap:
Variables:
- : Total replicas
- : Write quorum (nodes that must acknowledge)
- : Read quorum (nodes to read from)
Configurations:
- , : Fast reads, slow writes
- , : Fast writes, slow reads
- : Balanced
Typical setup ():
- , : Tolerates failure
- Strong consistency:
- Eventual consistency:
Choose quorum values based on your read/write ratio and consistency needs.