BeatPaxos

Can you make Paxos violate safety?
Round: 0
Score: 0 | Best: 0
Speed: 1x

Mission

Break consensus! Make two nodes decide different values. Paxos claims this is impossible — prove it wrong!

Controls

Double-click Kill / recover a node
Click & hold Delay a node's messages
Only one node can be down at a time.

Paxos Protocol

Phase 1 — Prepare p1a(ballot): "I want to lead with ballot B"
p1b(ballot, accepted): "I promise. Here's what I accepted." Phase 2 — Accept p2a(value, ballot): "Accept this value at ballot B"
p2b(ballot): "Accepted!" Phase 3 — Decision p3(value): "Value V is decided!"

Safety Invariant

"If a value is decided, no different value can ever be decided."
SAFETY HOLDS

Event Log

BeatPaxos

Can you break the consensus protocol?

Three nodes — Red, Green, and Blue — are running the Paxos consensus protocol. Each wants to decide its own color as the value.

Your goal: make two nodes decide different values. Kill nodes, delay messages, cause chaos. But Paxos guarantees safety...

Double-click a node to kill/recover it (only one can be down at a time).
Click & hold a node to delay its messages.