Definition
Picking a single coordinator among nodes, and agreeing on a new one when it dies.
How it works
Many systems need exactly one node in charge (the write primary, the scheduler). A consensus protocol (Raft, Paxos) or a coordination service (ZooKeeper, etcd) elects the leader and uses leases/heartbeats to fail over safely. The danger is split-brain — two nodes both believing they're leader — which fencing tokens and quorums prevent.
Common questions
What is Leader Election?
Picking a single coordinator among nodes, and agreeing on a new one when it dies.
How does Leader Election work?
Many systems need exactly one node in charge (the write primary, the scheduler). A consensus protocol (Raft, Paxos) or a coordination service (ZooKeeper, etcd) elects the leader and uses leases/heartbeats to fail over safely. The danger is split-brain — two nodes both believing…
What is Leader Election used for in system design?
Many systems need exactly one node in charge (the write primary, the scheduler). A consensus protocol (Raft, Paxos) or a coordination service (ZooKeeper, etcd) elects the leader and uses leases/heartbeats to fail over safely. The danger is split-brain — two nodes both believing…