[rmkr-dev]

Adds a Skillbook entry and a matching Promptbook entry for running recurring jobs safely in Spring Boot services with several replicas on AKS.

Skill: scheduled-jobs-shedlock-guardrails

• Placement per job: in-app @Scheduled + ShedLock, Kubernetes CronJob, leader election, or queue-driven, with trade-offs
• ShedLock with DB time, stable lock names, LockAssert, lockAtMostFor / lockAtLeastFor sized from measured runtime; skips, not queues, and not fencing
• Idempotent watermark-based work in bounded chunks with a time budget; scheduler pool sizing and graceful shutdown inside the pod grace period
• Cron zones and DST, six-field Spring cron vs five-field Kubernetes cron, scheduling on/off property
• CronJob concurrencyPolicy: Forbid, startingDeadlineSeconds, timeZone, backoffLimit, activeDeadlineSeconds, ttlSecondsAfterFinished, job profile with real exit codes
• Run logs, last-success gauge and "not run in N intervals" alerts; config, Flyway table, CronJob manifest, checklist, anti-patterns, SKILL.md stub

Prompt: make-scheduled-jobs-replica-safe

• Job inventory first, then placement, locks, idempotency, CronJob manifests, observability and rollout
• Two-instance Testcontainers test proving one run per tick before scaling out; no replicas: 1 workarounds

Catalogs go to 51 skills / 51 prompts. node scripts/site-check.mjs passes locally.