24 Hours of Autonomous Operations: What Broke and What Worked

We let VoxYZ run completely autonomous for 24 hours. Here's what we learned.

What Broke

1. Queue Overflow at 2.3x Normal Load

Problem: Job queue hit memory limits when processing volume jumped from 1.2k to 2.8k requests/hour.

Fix Applied:

• Implemented circuit breaker at 2k requests/hour
• Added overflow queue with 10-minute delay
• Result: Zero downtime on subsequent spikes

2. Log Rotation Filled Disk Space

Problem: Debug logs weren't rotating properly, consumed 47GB in 8 hours.

Immediate Action:

• Emergency log cleanup via cron
• Reduced log level from DEBUG to INFO
• Set max log size to 100MB with 5-file rotation

3. API Rate Limit Cascade

Problem: Third-party API rate limit (500/hour) triggered at 3 AM, causing 200+ failed jobs.

Solution:

• Added exponential backoff with jitter
• Implemented request queuing with 7.2 second intervals
• Built rate limit monitoring dashboard

What Worked Better Than Expected

Auto-scaling Performance

CPU-based auto-scaling handled traffic spikes flawlessly:

• Scaled from 2 to 8 instances in 90 seconds
• Scaled back down in 12 minutes
• Cost increase: only 23% despite 2.3x load

Error Recovery

Built-in retry logic resolved 89% of transient failures:

• Network timeouts: 94% recovery rate
• Database locks: 87% recovery rate
• Memory pressure: 91% recovery rate

Monitoring Gaps Found

• Missing: Disk space alerts (now set at 80% threshold)
• Missing: Queue depth trending (added 15-minute rolling average)
• Missing: Third-party API response time tracking

Next 24-Hour Test Changes

1. Pre-emptive scaling: Start scaling at 70% CPU vs 80%
2. Smarter retries: Different backoff strategies per error type
3. Resource buffers: 25% disk space buffer, 30% memory buffer

Key Metrics

• Uptime: 99.7% (4.3 minutes downtime total)
• Error rate: 0.3% (down from 2.1% baseline)
• Response time: 340ms average (within SLA)
• Cost efficiency: 15% better than manual operation

The biggest lesson: autonomous systems need better observability, not just automation.