🔥 The DB Grill 🔥

Alright, let's see what the marketing department, uh, I mean, the community outreach team has cooked up for us today.

clears throat, reads in a mock-serious tone

"At Percona, our mission has always been to provide the community with truly open-source, enterprise-class software."

Ah, yes, the mission. I remember the mission. The mission is what gets written on the blog post while my team is PagerDuty's sole source of income. "Enterprise-class" is a fantastic term. It's corporate bingo for "you're going to need an enterprise-sized budget to pay for the therapy my engineers will require after maintaining this."

And here we go, the meat of it. A security vulnerability. CVE-2025-14847. Lovely. Sounds important. And of course, Percona is responding with "urgency and transparency." Let me translate that for the people in the back who actually have to deploy this stuff. Urgency means my change-freeze for the upcoming holiday weekend just got vaporized. Transparency means we get a beautifully written blog post that explains the what but conveniently glosses over the how—as in, how this "simple" patch is going to interact with our six custom extensions and that one weird kernel flag we had to set three years ago to prevent data corruption.

But don't worry! I'm sure the upgrade path will be seamless. It always is. I can already see the Jira ticket. "Apply minor version patch. Estimated downtime: 0 minutes." Zero. Minutes. The most expensive lie in information technology.

I can picture the planning meeting now. Someone from architecture, who hasn't touched a terminal in five years, will say something like, "The documentation says it's a rolling, in-place upgrade. We'll just follow the procedure. It's a best practice."

The procedure. Right. Here's the procedure as it will actually happen, at 2:47 AM on the Saturday of Memorial Day weekend:

• Step 1: We'll drain and patch the first replica. Everything looks green. Confidence is high. Maybe this time it's different.
• Step 2: We'll patch the second replica. The cluster election takes a few milliseconds longer than usual, but the dashboard is still green. A single, nervous bead of sweat forms.
• Step 3: We patch the primary. It steps down gracefully, a new primary is elected, and for about 90 seconds, it feels like we're heroes.
• Step 4: The first user query hits the newly-patched cluster. The query planner, having been fundamentally altered in some undocumented way by the security fix, decides the most efficient way to fetch a single user's profile is to do a full collection scan and then cross-reference it with the entire Library of Congress.
• Step 5: The CPU on all nodes spikes to 100%. Latency graphs start looking like a seismograph during an earthquake. The alerts begin. Not all at once, but a slow, terrifying trickle. High CPU... high I/O wait... replication lag climbing...

And how will we know any of this is happening? With our enterprise-class monitoring, of course! Which is to say, the one Grafana dashboard the summer intern set up that tells us if the server is literally on fire. The patch notes won't mention which 37 new metrics we suddenly need to be tracking. That's a fun little game of discovery we get to play, with the company's revenue as the score.

"we respond with the urgency and transparency our users expect."

What I expect is for my on-call phone to start vibrating itself off the nightstand with an alert that just says CRITICAL: metric 'db_liveliness_factor_alpha' is -1. A metric that didn't exist an hour ago.

This whole song and dance... I've seen it a hundred times. I've got the stickers to prove it. I have a whole section of my laptop lid dedicated to the ghosts of databases past. There's RethinkDB, right next to a very faded one from a "hyper-scalable time-series" database called ChronoSpire that promised the world and then imploded. Every single one of them had a blog post just like this one. Full of missions and synergies and promises of painless, automated, zero-downtime operations.

So yeah, thanks for the patch, Percona. I'll get right on deploying it. My family had plans for that weekend, but I'm sure they'll understand. The mission, after all, is what's truly important. Now if you'll excuse me, I need to go pre-emptively write a post-mortem.