# Hitler Reacts to Removal of MySQL's Query Cache

The removal of the query cache in MySQL 8.0 improves user experience and has been celebrated by many members of the MySQL community. With this good news, obviously, Hitler isn’t happy. (Parody Video).

# Heavier-Than-Air Flight Is Impossible

When I was a child, my parents put a page from a newspaper on our refrigerator door. I remember it as a yellowed, faded piece of paper that seemed like it had always been there. It was filled with little oval portraits of famous people proclaiming that heavier-than-air flight was impossible. My memory is that there were perhaps 40 of them, each with a quote and a date within a few years of the Wright Brothers’ flight at Kitty Hawk.

This might be one of the childhood influences that resonates most strongly in me today. There are dozens of examples of people disdainfully saying “you can’t do that” during my career.

I tried to find an image of the page I remember, but didn’t (maybe it’s impossible?), so I looked for quotes and am producing my own version of it below.

# How To Write Exciting Conference Proposals

Most conference proposals are too boring, even when the speakers and topics are great. This is a pity. I think something about the process of submitting to a CfP sets a trap for most speakers. This post is my advice for avoiding that trap.

TL;DR: Your proposal should focus on your story about what you’ve done personally and what you’ve learned. Your story, not the topic. And, don’t tell us anything about the importance of the topic or how high the stakes are.

# Monitoring with Artificial Intelligence and Machine Learning

Artificial intelligence and machine learning (AI and ML) are so over-hyped today that I usually don’t talk about them. But there are real and valid uses for these technologies in monitoring and performance management. Some companies have already been employing ML and AI with good results for a long time. VividCortex’s own adaptive fault detection uses ML, a fact we don’t generally publicize.

AI and ML aren’t magic, and I think we need a broader understanding of this. And understanding that there are a few types of ML use cases, especially for monitoring, could be useful to a lot of people.

# Analyzing Changing Workloads with the USL

Production servers often have much more dynamic, complex workload and behaviors than you might be accustomed to seeing, because most monitoring products aggregate system behavior into high-level global metrics, losing all the detail. Multivariate analysis by another dimension often reveals something unexpected about server behavior. This can prompt you to explore the system, and sometimes leads to a deeper understanding of it. Here’s one such example.

# Interviewing

A couple of years ago, during a time of crisis in my company, I realized I’d created a mess. But the scariest thing was I didn’t know what I’d done wrong. Of all the many things I did, what, exactly, was making things go so badly? It turned out that most of my problems were caused by bad interviewing technique. I was setting every interview up for failure, and I didn’t know it.

# Defining Moments in Database History

The rise of the LAMP stack in the early- to mid-2000s created a shift in the technology landscape, as well as the impetus for contenders to emerge. I’ve been reflecting on key factors in that phenomenon and what’s happened since then—and what it can teach us about what’s happening now.

# Writing Kindly

It makes me a bit uncomfortable when people say I’m a good person, because sometimes I’m actually a jerk! Thankfully, I’ve found that gentleness is a skill I can learn if I care enough to try, and I’ve gotten better at it over time. I’ve also found that when I’m nice and I focus on the positive, I get better results. Here are some things I’ve learned about how to be a kinder person in my writing.

# Charlottesville Coffee Roasters

One of the things I appreciate about living in beautiful Charlottesville, Virginia is the abundance of artisanal products that are high-quality and produced locally. There’s a vibrant network of people making food, drink, and physical goods: wineries, chocolate, art, blacksmithing, and much more. Many of our local producers are recognized worldwide. As a newly minted coffee lover, I also appreciate the variety and quality of coffee roasters in town and nearby. Of course, we have to import the beans, but there’s much to the coffee story after the beans are harvested. Here are some of my favorite local coffee resources.

# Simple Guidelines For Maintainable Spreadsheets

The spreadsheet is one of the most powerful inventions in the history of computing. But with that power comes responsibility: just as with a programming language, the spreadsheet itself can become difficult to understand and maintain.

# The Best Activity Tracking Watch

After thinking about smart watches, activity trackers, and similar devices for a while, I bought a Withings Steel HR. My goal was to find a traditional stylish-looking watch with long battery life, heart rate tracking, sleep tracking, and activity tracking. Here’s my experience thus far.

TL;DR: Using the Withings Steel HR has changed the way I use my smartphone. I love how much less distracted I am. I am happy with the health tracking features, and I like the traditional watch styling and long battery life.

# How Venture Capitalists Have Helped Me

Venture capital is a competitive industry. Investors compete to win the best companies, so they pitch founders on the value they bring to their portfolio companies. When I was a new founder, their pitches didn’t resonate with me. I found it difficult to understand how they could help. A few years later, I get it; they really can add value. This is what I’ve found so far.

Leadership is, by definition, a process of transition. None of us is born to be a leader. Those who are leaders have become leaders through change, and it is a very difficult and unnatural process. A lot of this process involves learning, through repeatedly asking and answering the question, “what does a leader do?”

As a first-time CEO, I ask this question of other CEOs again and again, and write down their answers. I also find food for thought in blogs and books. As you might expect, answers from different CEOs differ a lot, but they have similarities.

# Product Market Fit

The way I think about product/market fit has changed a lot over the years. I view it differently than I used to.

# The Erlang Response Time Stretch Factor For 3 And 4 Servers

In a previous post I explored a few variations of equations that express the M/M/m queueing theory response time “stretch factor,” and tried to indicate some areas where I wanted to dig into the relationships between these formulas a bit more. In this post I discuss the divergence between the official Erlang C formula and Neil Gunther’s heuristic approximation to it. I introduced this before thusly:

At $$m=3$$ and above, the heuristic is only approximate. What does the Erlang form reduce to for the first of those cases? Does it result in the missing term that will extend to 4 and beyond too?

# Better Than The Golden Rule

The so-called Golden Rule is well recognized within Western culture, although most other cultures have similar concepts. Can you do better? I think the answer is yes, and it’s good to try.

# The Queueing Knee, Part 2

Last week I wrote about the so-called “knee” in the M/M/m queueing theory response time curve. In that post I examined one definition of the knee; here is my analysis of the others, including the idea that there is no such thing as the knee.

There are potentially several ways to think about the “knee” in the queueing curve. In the previous post I dug into Cary Millsap’s definition: the knee is the point where a line tangent to the queueing curve passes through the origin:

Here are a few others to consider:

# The Queueing Knee, Part 1

The “knee” in the M/M/m queueing theory response time curve is a topic of some debate in the performance community. Some say “the knee is at 75% utilization; everyone knows that.” Others say “it depends.” Others say “there is no knee.”

Depending on the definition, there is a knee, but there are several definitions and you may choose the one you want. In this post I’ll use a definition proposed by Cary Millsap: the knee is where a line from the origin is tangent to the queueing response time curve. The result is a function of the number of service channels, and although we may argue about the topics in the preceding paragraph and whether this is the right definition, it still serves to illustrate important concepts.

# A Great Mid-Priced Stereo System

You probably know that I like to be pretty minimalistic, and don’t accumulate a lot of “stuff” in my life. Yet for the few material things I value, I try to find the sweet spot: quality above average, price no higher than needed.

Music is one of the things I care a lot about: I have bought thousands of CDs. But I also value when my music sounds as good as possible. I treated myself to an upgraded stereo system so I’d enjoy better audio quality. Here’s my current system.