DS1_ETH

How does a node in Paxos know if a majority answered with ok?

• Each node needs to know the number n of servers in the system.

• the messages contain information that they are part of a majority

• the last message of the majority also notifies that now a majority is reached

Does the Paxos algorithm in the script achieve state replication?

• No

• Yes

How many nodes could crash so the Paxos still works?

• < n/2

• > n/2

• < n/3

• < n

Does Paxos solve consensus?

• No, termination is not guaranteed.

• No, agreement is not guaranteed.

• No, validity is not guaranteed.

• Yes, all 3 requirements are guaranteed

State replication is trivial for fewer than 3 nodes?

• No

• Yes

In Paxos, a new ticket can only be issued if all previous tickets have been returned.

• No

• Yes

Which is not a property of consenus?

• Agreement

• Termination

• Tolerance

• Validity

In a synchronous system, a message has a delay of ___ time units.

• 1

• n

• f

• n-f