Eavan's Blog

Service Level Objectives (SLOs) are great! Alerts based on SLOs are great! Alerts based on SLOs promise to reduce noise by only alerting on true service degradations, reducing noise and alert fatigue. Everyone uses the multi-window multi-burn-rate (MWMB) method for defining SLO alerts, because Google recommends it. But now that I've seen how this alert behaves in the real world, I think it's an overcomplicated mess with too many moving parts that interact in confusing ways to create alert spam that is hard to explain. Simply removing some of these moving parts can improve your on-call experience.

When I wrote Beautiful Abelian Sandpiles I wanted to show off some nice images of large identity sandpiles. But the simple algorithm I used was horrendously slow. Showing a sandpile identity that was larger than 100 by 100 took multiple seconds! That's not good enough! I became obsessed with trying to find a faster way, all in an effort to compute bigger and bigger sandpile identities, bigger than anything anyone had seen before. In the end, I did exactly that.

Confronting Reality (x86-64 Code Generation)

The Pareto Principle states that 80% of results come from 20% of the effort. The mistake is then to look at your impressive results (from part 2) and conclude that you are 80% done. The last 20% take the remaining 80% of your effort. You're not even halfway to the halfway point.

I can't remember where I first saw them, but ever since, I have been unable to forget them: abelian sandpiles. I'm far from the only one. They're remarkably simple, yet produce lovely symmetric patterns. I loved them so much that I adorned the title banner of this blog with an animation of an abelian sandpile. But what exactly are abelian sandpiles? How do they work? And how many pretty, mesmerizing pictures can we make with these things?

Alert fatigue is a spectre haunting DevOps teams. We all know that the spectre is there. In our post-mortems, we all acknowledge its impact on detection times and burnout. Yet, as an industry, we have no structural solution, and we rely on our burnt-out colleagues to tune, improve, ignore, and delete alerts when we feel the effects of alert fatigue set in. If you have ever felt that your alerts can be divided into categories of "Alerts I can ignore" (warning) and "Alerts I cannot ignore" (critical), then you are well aware that your sanity is finite. You need a budget!

Checking My Sanity (Semantic Analysis and Type Checking)

With my first step taken, my confidence was sky high and I was ready to take my second step. I had my AST, it would be good to check if it actually meant anything. And if so, what? What is the semantics of the program I had parsed. This sounds quite abstract, but as far as I was concerned, the only things that are absolutely essential are checking what symbols are distinct and checking types. Maybe I forgot something, but if so, it probably wasn't important... I hope.

Hello Newguy! I'm glad to see that you've completed your on-boarding here at Corp. Générique. I have your first ticket ready. It's a simple task. Just 2 story points. But it should give you the opportunity to learn a little about how our services work together. Simply implement an availability SLOService Level Objective for our cherished Foo service. You know how to implement an SLO, right?

If you want to learn many things, is it best to learn them one at a time? Or is it best to find the perfect project that combines all the things you want to learn? Will the effects of cognitive overload be too great to handle? Or will the added struggle just add to the effect of learning? In an attempt to learn both C and compiler design at the same time I unwittingly experiment on myself to aid in finding answers to these questions. My simple intuition says that this will be a disaster, but intuitions must be tested. They are sometimes wrong.

Welcome to my blog! A new home for the ideas that come into my head that need a place to live and make themselves comfortable. I intend for this place to be a tool for myself to sharpen my own ideas. Above all, this blog will be an excuse for me to justify putting time into my own ideas. Perhaps some of these ideas might even be interesting to you. That is for you to decide. And I look forward to finding out!