Customers ask us for p99 (99th percentile) of metrics pretty frequently. We plan to add such a feature to Database Performance Monitor (DPM)(more on that later). But a lot of…
Baron Schwartz
Baron Schwartz
The Latest Posts Featuring Baron Schwartz
Why Percentiles Don’t Work the Way You Think
The Factors That Impact Availability, Visualized
We all want our systems to have high availability, but sometimes the exact meaning of “high availability” isn’t very clearly defined. However, availability — like scalability, performance, and so on…
Nobody Loves Graphite Anymore
Many of our customers use Graphite, and I don’t think anyone would argue with me when I say it’s probably the most commonly used time series database in the DevOps…
What Is InnoDB History List Length?
Houston, we have a problem. Google search for “What is innodb history list length?” and you get a bunch of nonsense mixed in with correct information, and it’s hard to…
Securing JSON APIs With Wrapper Objects
Security is a top priority. Leading companies such as Zappos, Dyn, and Etsy use Database Performance Monitor (DPM), a cloud-based database performance management service to monitor MySQL in production designed…
Go’s Connection Pool, Retries, and Timeouts
This is a story of intermittent 500 Internal Server errors from APIs, that ended up being caused by a hardcoded constant in Go’s database/sql package. I’ll mostly spare you the…
How Exponentially Weighted Moving Averages Work
We use exponentially weighted moving averages (EWMAs) quite a bit in a few algorithms. They’re one of the tricks everyone should have in their toolbox for cheaply approximating recent history…
4 Things To Know About MySQL Prepared Statements
While writing our TCP stream reassembly and MySQL protocol reverse-engineering algorithms, a few finer points of the MySQL protocol and internals came up. None of this is new information, but…
A Tale of Two Memory Leaks in Go
In this post I’ll illustrate two ways I’ve accidentally caused slow but steady memory consumption in Go programs. The phrase “memory leak” isn’t really accurate, but I can’t think of…
Big-O Notation Made Simple
If you’re a programmer or computer scientist, you’re probably familiar with Big-O notation. It’s part of your foundational understanding of how complex a problem and/or algorithm is. But most explanations…