Leader Election
High Priority10 min readUpdated June 12, 2026
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Leader election is the process of choosing one node to coordinate work for a group.
A leader might:
- accept writes for a replicated database
- assign jobs to workers
- own a shard or partition
- run a controller loop
- coordinate failover
- serialize changes to shared metadata
The leader role simplifies many systems because one node decides the order of operations. The hard part is keeping that role safe when machines crash, networks partition, clocks drift, or old leaders keep running after losing contact with the cluster.
Every node does not need to know the leader instantly. Only a valid leader should be able to make decisions that matter.