- P Values are not Error Probabilities (PDF) — In particular, we illustrate how this mixing of statistical testing methodologies has resulted in widespread confusion over the interpretation of p values (evidential measures) and α levels (measures of error). We demonstrate that this confusion was a problem between the Fisherian and Neyman–Pearson camps, is not uncommon among statisticians, is prevalent in statistics textbooks, and is well nigh universal in the pages of leading (marketing) journals. This mass confusion, in turn, has rendered applications of classical statistical testing all but meaningless among applied researchers.
- Breaking the 1000ms Time to Glass Mobile Barrier (YouTube) —
See also slides. Stay under 250 ms to feel “fast.” Stay under 1000 ms to keep users’ attention.
- Modern Methods for Sentiment Analysis — Recently, Google developed a method called Word2Vec that captures the context of words, while at the same time reducing the size of the data. Gentle introduction, with code.
A brief history of SPDY and HTTP/2.
SPDY was an experimental protocol, developed at Google and announced in mid-2009, whose primary goal was to try to reduce the load latency of web pages by addressing some of the well-known performance limitations of HTTP/1.1. Specifically, the outlined project goals were set as follows:
- Target a 50% reduction in page load time (PLT).
- Avoid the need for any changes to content by website authors.
- Minimize deployment complexity, avoid changes in network infrastructure.
- Develop this new protocol in partnership with the open-source community.
- Gather real performance data to (in)validate the experimental protocol.
To achieve the 50% PLT improvement, SPDY aimed to make more efficient use of the underlying TCP connection by introducing a new binary framing layer to enable request and response multiplexing, prioritization, and header compression.
Not long after the initial announcement, Mike Belshe and Roberto Peon, both software engineers at Google, shared their first results, documentation, and source code for the experimental implementation of the new SPDY protocol:
So far we have only tested SPDY in lab conditions. The initial results are very encouraging: when we download the top 25 websites over simulated home network connections, we see a significant improvement in performance—pages loaded up to 55% faster.
— A 2x Faster Web Chromium Blog
Fast-forward to 2012 and the new experimental protocol was supported in Chrome, Firefox, and Opera, and a rapidly growing number of sites, both large (e.g. Google, Twitter, Facebook) and small, were deploying SPDY within their infrastructure. In effect, SPDY was on track to become a de facto standard through growing industry adoption.
The secret to successful infrastructure automation is people.
“The trouble with automation is that it often gives us what we don’t need at the cost of what we do.” —Nicholas Carr, The Glass Cage: Automation and Us
Virtualization and cloud hosting platforms have pervasively decoupled infrastructure from its underlying hardware over the past decade. This has led to a massive shift towards what many are calling dynamic infrastructure, wherein infrastructure and the tools and services used to manage it are treated as code, allowing operations teams to adopt software approaches that have dramatically changed how they operate. But with automation comes a great deal of fear, uncertainty and doubt.
Common (mis)perceptions of automation tend to pop up at the extreme ends: It will either liberate your people to never have to worry about mundane tasks and details, running intelligently in the background, or it will make SysAdmins irrelevant and eventually replace all IT jobs (and beyond). Of course, the truth is very much somewhere in between, and relies on a fundamental rethinking of the relationship between humans and automation.
From design processes to postmortem complexity, here are key insights from Velocity Europe 2014.
Practitioners and experts from the web operations and performance worlds came together in Barcelona, Spain for Velocity Europe 2014. We’ve gathered highlights and insights from the event below.
Managing performance is like herding cats
Aaron Rudger, senior product marketing manager at Keynote Systems, says bridging the communication gap between IT and the marketing and business sectors is a bit like herding cats. Successful communication requires a narrative that discusses performance in the context of key business metrics, such as user engagement, abandonment, impression count, and revenue.
How NoSQL databases scale vertically and horizontally, and what you should consider when building a DB cluster.
Editor’s note: this post is a follow-up to a recent webcast, “Getting the Most Out of Your NoSQL DB,” by the post author, Alex Bordei.
As product manager for Bigstep’s Full Metal Cloud, I work with a lot of amazing technologies. Most of my work actually involves pushing applications to their limits. My mission is simple: make sure we get the highest performance possible out of each setup we test, then use that knowledge to constantly improve our services.
Here are some of the things I’ve learned along the way about how NoSQL databases scale vertically and horizontally, and what things you should consider when building a DB cluster. Some of these findings can be applied to RDBMS as well, so read on even if you’re still a devoted SQL fan. You might just get up to 60% more performance out of that database soon enough. Read more…
From the lure of work that matters to building your own device lab, here are key talks from Velocity New York 2014.
Practitioners and experts from the web operations and performance worlds came together in New York City this week for Velocity New York 2014. Below you’ll find a handful of keynotes and interviews from the event that we found particularly notable.
Mikey Dickerson: From Google to HealthCare.gov to the U.S. Digital Service
“These problems are fixable, these problems are important, but they require you to choose to work on them” — Mikey Dickerson looks back on what it took to fix HealthCare.gov and he reveals his reasons for joining the U.S. Digital Service.