When should automated maintenance run? Some teams schedule maintenance at fixed times - daily, weekly, monthly. Others trigger maintenance based on events - when PRs are opened, when deployments happen, when issues are detected. Both approaches work, but they serve different purposes.
Scheduled maintenance provides predictability and routine. Event-triggered maintenance provides responsiveness and relevance. Understanding when each approach fits helps you design maintenance systems that run at the right time for the right reasons.
Scheduled Maintenance: Time-Based Triggers
Scheduled maintenance runs at predetermined times.
How Scheduled Maintenance Works
Maintenance runs on a schedule:
@devonair scheduled maintenance:
- Daily at 2 AM: Security scan
- Weekly on Tuesday: Dependency updates
- Monthly on the 1st: Comprehensive audit
Time determines when maintenance happens.
Common Scheduling Patterns
Daily Schedule
High-frequency tasks:
@devonair daily schedule:
- Security vulnerability scan
- Build verification
- Test suite execution
- Monitoring of key metrics
Daily for critical, fast checks.
Weekly Schedule
Moderate-frequency tasks:
@devonair weekly schedule:
- Dependency updates
- Code quality reports
- Performance benchmarks
- Technical debt assessment
Weekly for routine maintenance.
Monthly Schedule
Lower-frequency comprehensive tasks:
@devonair monthly schedule:
- Full codebase audit
- License compliance check
- Comprehensive security review
- Architecture health check
Monthly for thorough reviews.
Strengths of Scheduled Maintenance
Predictability
Know when maintenance runs:
Scheduled strength:
- Consistent timing
- Can plan around it
- Stakeholders know the cadence
- Expectations are set
Predictability enables planning.
Complete Coverage
Everything gets checked eventually:
Scheduled strength:
- All code scanned on schedule
- Nothing falls through cracks
- Systematic coverage
- Comprehensive checks
Schedules ensure nothing is forgotten.
Reduced Noise
Batched results rather than continuous:
Scheduled strength:
- One report per period
- Not constant notifications
- Easier to process
- Less alert fatigue
Batching reduces notification overhead.
Resource Predictability
Known resource usage:
Scheduled strength:
- Can allocate resources
- Off-peak scheduling possible
- Cost predictable
- Capacity planning easier
Scheduled work has predictable resource needs.
Weaknesses of Scheduled Maintenance
Delayed Response
Issues wait until scheduled time:
Scheduled weakness:
- Vulnerability disclosed Monday
- Weekly scan runs Friday
- 4 days of exposure
Schedules introduce latency.
Irrelevant Runs
Runs even when not needed:
Scheduled weakness:
- No changes since last run
- But maintenance runs anyway
- Wasted resources
- Wasted attention
Schedules may run unnecessarily.
Batched Problems
Accumulation between runs:
Scheduled weakness:
- Issues accumulate
- Big batch when run executes
- Harder to process large batches
Batching can create overwhelming output.
Event-Triggered Maintenance: Responsive Triggers
Event-triggered maintenance runs when something happens.
How Event-Triggered Maintenance Works
Events trigger maintenance:
@devonair event-triggered maintenance:
- On PR opened: Run quality checks
- On dependency change: Security scan
- On deploy: Verify health
- On alert: Diagnostic analysis
Events determine when maintenance happens.
Common Event Triggers
Code Change Events
Triggered by development activity:
@devonair code change triggers:
- PR opened → Quality check
- PR merged → Integration verification
- Commit pushed → Build verification
Development activity triggers relevant checks.
Dependency Events
Triggered by dependency changes:
@devonair dependency triggers:
- New version released → Update check
- Vulnerability disclosed → Security scan
- License change detected → Compliance check
Dependency events trigger dependency maintenance.
Deployment Events
Triggered by deployments:
@devonair deployment triggers:
- Pre-deploy → Verification
- Post-deploy → Health check
- Rollback → Analysis
Deployment events trigger deployment-related maintenance.
Monitoring Events
Triggered by system state:
@devonair monitoring triggers:
- Error rate spike → Diagnostic analysis
- Performance degradation → Profiling
- Threshold exceeded → Investigation
System events trigger responsive maintenance.
Strengths of Event-Triggered Maintenance
Immediate Response
Act when relevant:
@devonair triggered strength:
- Vulnerability disclosed → Immediate scan
- PR opened → Immediate feedback
- Issue detected → Immediate response
Events trigger immediate action.
Relevance
Maintenance runs when needed:
@devonair triggered strength:
- PR changed dependencies → Dependency check
- No dependency change → No check needed
- Resources used when relevant
Triggered maintenance is inherently relevant.
Fast Feedback
Developers get quick response:
@devonair triggered strength:
- Open PR → Results in minutes
- Not waiting for scheduled run
- Faster iteration
Fast feedback improves developer experience.
Resource Efficiency
Resources used when valuable:
@devonair triggered strength:
- No activity → No resources used
- High activity → Resources match need
- Scales with actual work
Resources scale with activity.
Weaknesses of Event-Triggered Maintenance
Missing Dormant Code
Unchanged code never checked:
Triggered weakness:
- Code not touched in a year
- No events trigger
- Issues accumulate undetected
Event triggers miss inactive areas.
Unpredictable Timing
Can't plan around it:
Triggered weakness:
- Don't know when it runs
- Resource usage spiky
- Harder to plan capacity
Event patterns are unpredictable.
Potentially High Volume
Many events may trigger many runs:
Triggered weakness:
- Active development = many triggers
- Could overwhelm
- May need throttling
High activity creates high maintenance volume.
Event Coverage Gaps
Not all important things have events:
Triggered weakness:
- New vulnerability in unchanged dependency
- No code event to trigger
- May be missed
Some conditions lack triggering events.
Comparing the Approaches
Direct comparison across key dimensions.
Responsiveness
| Factor | Scheduled | Event-Triggered | |--------|-----------|-----------------| | Time to detection | Next scheduled run | Immediate | | Response latency | Hours to days | Minutes | | Developer feedback speed | Slow | Fast |
Event-triggered is more responsive.
Coverage
| Factor | Scheduled | Event-Triggered | |--------|-----------|-----------------| | Active code | Good | Excellent | | Dormant code | Excellent | Poor | | Completeness | Comprehensive | Activity-dependent |
Scheduled provides more complete coverage.
Resource Usage
| Factor | Scheduled | Event-Triggered | |--------|-----------|-----------------| | Predictability | High | Low | | Efficiency | Variable | High | | Peak usage | Controlled | Uncontrolled |
Different resource patterns.
Developer Experience
| Factor | Scheduled | Event-Triggered | |--------|-----------|-----------------| | Feedback speed | Slow | Fast | | Relevance of feedback | Variable | High | | Notification volume | Batched | Per-event |
Event-triggered provides better developer experience for active work.
The Hybrid Approach
Most effective systems combine both.
Event-Triggered for Active Development
Real-time feedback on changes:
@devonair event-triggered layer:
- PR opened → Quality checks
- Dependencies changed → Security scan
- Deploy initiated → Verification
Immediate feedback for developer activity.
Scheduled for Completeness
Comprehensive periodic checks:
@devonair scheduled layer:
- Daily: Security scan (catch external disclosures)
- Weekly: Full codebase quality check
- Monthly: Comprehensive audit
Scheduled catches what events miss.
Combined Benefits
@devonair combined approach:
- Responsive + Comprehensive
- Fast feedback + Complete coverage
- Relevant + Thorough
Hybrid captures benefits of both.
Designing Trigger Strategy
How to decide what triggers what.
Match Trigger to Task
@devonair trigger matching:
- Fast, targeted checks → Event-triggered
- Comprehensive scans → Scheduled
- Real-time feedback needed → Event-triggered
- Complete coverage needed → Scheduled
Task requirements determine trigger type.
Consider Resource Impact
@devonair resource consideration:
- Light checks → Event-triggered is fine
- Heavy analysis → Scheduled to control load
- User-facing impact → Event-triggered for speed
Resource impact influences trigger choice.
Consider Frequency
@devonair frequency consideration:
- High-frequency events → Consider rate limiting
- Low-frequency but critical → Schedule as backup
Frequency affects design.
Implementation Patterns
Putting triggers into practice.
Event Triggers
@devonair implement event triggers:
- Webhook from GitHub on PR
- Notification on deployment
- Alert from monitoring system
Events flow from existing systems.
Scheduled Triggers
@devonair implement scheduled triggers:
- Cron jobs
- Scheduled GitHub Actions
- Cloud scheduler
Schedules use standard scheduling infrastructure.
Combining Both
@devonair combine triggers:
- Same maintenance tasks
- Multiple trigger sources
- Idempotent execution
Tasks can be triggered either way.
Getting Started
Design your trigger strategy.
Inventory maintenance tasks:
@devonair inventory:
- What maintenance do you need?
- What's time-sensitive?
- What needs completeness?
Assign triggers:
@devonair assign triggers:
- Event-triggered for responsive needs
- Scheduled for comprehensive needs
- Both for critical tasks
Implement:
@devonair implement:
- Set up event integrations
- Configure schedules
- Verify both work
The choice between scheduled and event-triggered maintenance isn't either/or. Both have roles. Event triggers provide responsiveness; schedules provide completeness. Combined thoughtfully, they create maintenance systems that are both fast and thorough.
FAQ
Should everything be event-triggered for maximum responsiveness?
No. Event-triggered misses dormant code and external changes (like newly disclosed vulnerabilities in unchanged dependencies). Use scheduled maintenance to catch what events miss.
How do we avoid duplication when using both?
Make maintenance tasks idempotent and cache-aware. If an event-triggered run just finished, a scheduled run can detect nothing changed and skip or return cached results.
What about rate limiting event-triggered maintenance?
Yes, implement rate limiting for high-frequency events. Debounce multiple rapid events into single runs. Queue work during peak activity. The goal is responsiveness, not one run per keystroke.
How often should scheduled maintenance run?
It depends on the task. Security scans: daily or more often. Quality reports: weekly. Comprehensive audits: monthly. Balance thoroughness with resource usage and attention capacity.