The Leak We Lived With for a Year

Welcome back to the Manchester Tech Blog. Today we are sharing a rather embarrassing story about a memory leak that had been quietly degrading our production servers for twelve long months. Back in early 2021, our main database service started showing signs of trouble. It was getting sluggish during peak hours, and nobody knew why.

At first, we thought it was just regular database corruption caused by old disk space limits. We checked our FAQ page, followed every troubleshooting how-to guide, and even reached out to our cloud vendor. Nothing worked. The memory usage kept creeping up every single day, threatening to crash the entire system without warning.

Then one exhausted Friday night, Sam decided to apply a quick band-aid. He wrote a small script to restart the service automatically every night at 3 AM. It seemed like a clever fix at the time. The restarts cleared the heap, and our graphs looked clean again. We assumed the problem was solved.

Except it wasn't solved at all. Because of that nightly restart, the underlying memory leak had been going completely unnoticed for an entire year. The server would bloat, reach a tipping point, and then vanish into thin air every night before anyone could investigate the root cause.

Last week, Samantha joined our team as the new senior developer in charge of system reliability. While reviewing our cron jobs, she noticed the mysterious midnight restart script. She commented it out just to see what would happen on a quiet Tuesday morning.

Within six hours, the server memory had climbed past ninety percent. Garbage collection stopped working efficiently, and the system began to crawl. We finally saw the true scale of the degradation. Samantha checked the logs and found a massive memory leak hidden deep inside our caching layer.

We have since rewritten that broken module and removed Sam's old band-aid script for good. The lesson here is simple: never hide a chronic software bug with a midnight restart. Sooner or later, your temporary fix will catch up with you, and the truth will come out.

Read again and choose the right answer

How long had the memory leak been hidden before the team discovered it?

• One month
• One year
• Two years

What had been hiding the memory leak from the engineers?

• A nightly automatic restart script
• A firewall configuration error
• A corrupted hard disk

Who discovered the hidden script while reviewing cron jobs?

• Sam
• Michelle
• Samantha

What advice do the authors give at the end of the blog post?

• Never hide a chronic software bug with a midnight restart
• Always buy more disk space when servers slow down
• Never contact cloud vendors for technical support

Sources: photo by Christina Morillo on Pexels