Course outline

01 · HTTP & REST APIs

02 · Databases & Persistence

03 · Authentication & Authorization

04 · API Design & gRPC

05 · Caching, Queues & Background Jobs

06 · Production-Ready Services

07 · Advanced Auth & Tenant Security

08 · Performance & Caching at Scale

09 · Testing & Release Confidence

Stage 3 · Build

Caching, Queues & Background Jobs

Background Scheduling

Run cron-like jobs with robfig/cron, distributed locks, idempotency keys, and job observability.

7 min readBuilding Backend ApplicationsBuild

Why Background Jobs

Not all work belongs in an HTTP handler. Sending emails, generating reports, cleaning up stale data, and syncing external services should run in the background. Scheduled jobs handle periodic tasks without user interaction.

robfig/cron

Gocron-scheduler-setup.go

27 linesLn 1, Col 1Go

robfig/cron parses standard cron expressions. WithSeconds() enables second-level precision. AddFunc registers a function to run on a schedule. Start begins the scheduler in a background goroutine.

Distributed Locks

When running multiple instances, the same cron job runs on every instance. Use distributed locks to ensure only one instance executes the job.

Goredis-based-distributed-lock.go

26 linesLn 1, Col 1Go

SetNX sets a key only if it does not exist, with a TTL. If another instance already holds the lock, SetNX returns false. The TTL ensures the lock expires even if the instance crashes.

Idempotency

Goidempotent-job-execution.go

19 linesLn 1, Col 1Go

Idempotency keys prevent the same job from executing twice. This is critical for jobs that send emails, process payments, or modify external state.

Job Observability

Gojob-execution-tracking.go

39 linesLn 1, Col 1Go

Track job execution time, status, and errors. Store results for monitoring dashboards. Alert on repeated failures or excessive duration.

Scheduling Patterns

Cleanup jobs: Remove expired sessions, stale data, old logs.
Sync jobs: Pull data from external APIs, update caches.
Report jobs: Generate daily/weekly reports, send summaries.
Health jobs: Check dependency health, restart failed services.
Rotation jobs: Rotate API keys, certificates, encryption keys.

Log every job execution

Always log when a job starts, completes, or fails. Include the job name, duration, and any errors. This makes debugging scheduled job issues possible.

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