Runtime model
Latest stable Based on Leader release 0.4.0
Trace one election from contender entry through ownership, action execution, observation, and release.
The critical path
Section titled “The critical path”An elector validates the lock name, waits up to waitTime, and asks its backend to acquire ownership atomically. A failed acquire publishes a skipped signal and returns null or LeaderRunResult.Skipped. A successful acquire creates a scoped lock handle, publishes elected, runs the action, records completion or failure, then releases only with matching ownership.
Lease is not a transaction
Section titled “Lease is not a transaction”Leadership prevents another compliant contender from entering the guarded section during the valid lease. It does not roll back external writes and it cannot stop work after a process pause or network partition. The action must therefore be idempotent, and destructive downstream systems should validate a fencing token where available.
Observation is best effort
Section titled “Observation is best effort”state(lockName) and event streams help operators understand the system, but they are snapshots. Never read state and then decide that acquisition is safe; only the backend’s atomic acquire path owns that decision. leaseUntil can be absent or approximate depending on the backend.
Release sources
Section titled “Release sources”leader-core/src/main/kotlin/io/bluetape4k/leader/LeaderElector.ktleader-core/src/main/kotlin/io/bluetape4k/leader/LeaderState.ktleader-core/src/main/kotlin/io/bluetape4k/leader/LeaderLease.kt