LuTiao Programming

Sep 5, 2026 · Backend Development

Why @Scheduled Runs 3× in Kubernetes: Migrating to JobRunr for Distributed Tasks

After scaling a Spring Boot app to three Kubernetes replicas, @Scheduled tasks ran thrice, generating duplicate reports. The author evaluates distributed locks but adopts JobRunr for persistent, retryable, and monitorable background jobs, demonstrating integration with Spring Boot 4, code patterns for fire-and-forget, recurring, and delayed tasks, plus idempotency and deduplication strategies.