A Replicated Server System
Maintaining consistent servers [Sch90] :
- To tolerate f benign faults, 2f+1 servers are needed.
- To tolerate f malicious faults: 3f+1 servers are needed.
Responding to read-only clients’ request [Sch90] :
- If the servers support only benign faults: 1 answer is enough.
- If the servers can be malicious: the client must wait for f +1 identical answers, f being the number of malicious servers.