Peter and Vadim are long-term contributors to MySQL open source code base and are the founders of Percona, MySQL consultancy. This is really THE book about MySQL written by engineers who have spent more than a decade working on MySQL code. The book is equally valuable to devops and DB admins, as well as software …
Cohort analysis is super important if you want to know if your service is in fact a leaky bucket despite nice growth of absolute numbers. There’s a good write up on that subject “Cohorts, Retention, Churn, ARPU” by Matt Johnson. So how to do it using R and how to visualize it. Inspired by examples …
Continue reading “Measuring user retention using cohort analysis with R”
Should you buy a book on a new technology or just read technology provider’s guidelines, instructions and recommendations? This book was released over a year ago, so naturally it doesn’t cover all the latest developments that happened on Amazon AWS platform. For example Simple Email Service (SES) and Dynamo DB are not mentioned at all. After …
After repeating these operations many times in various setups, I decided to create a public set of instructions and share them with the world. This should be suitable for most of the simple web sites, utilizing Ruby on Rails or PHP.
The setup works on Ubuntu 10.04 Server LTS (scheduled end of life April 2015). Other components of the setup are Nginx as the web server, Phusion Passenger as application server.
I’m using this setup most often on Linode VPS, however none of the instructions are Linode specific.
Continue readingSetting up and securing web server (+MySQL +Rails/PHP) on Ubuntu 10.04 LTS
Spending 3 days with people who are working at the bleeding edge of data science was an unforgettable experience. I got my doze of inspiration and got a lot of new ideas how to apply data science in HeiaHeia. It’s difficult to underestimate the importance data analysis will have in the nearest years. Companies that do not get the importance of understanding data and making their decisions based on data analysis instead of gut feeling of board members/operative management will simply fade away.
Unfortunately HeiaHeia was the only company from Finland attending the conference. But I’m really happy to see that recently there are more and more signals that companies in Finland are starting to realize the importance of data, and there are new Finnish start-ups dealing with data analysis. I believe that Finland has an excellent opportunity to have not only a cluster of game development companies, but also big data companies and start-ups. So far it seems that the Valley, London and Australia are leading in this field.
By the way, Trulia (co-founded by Sami Inkinen) had an excellent demo in the halls of the conference venue – check it out in their blog.
Below are my notes from the conference – I added presentation links and videos that I have found, but otherwise those are quite unstructured. There were multiple tracks and it was very difficult to choose between them. Highlights of the conference are talks by Avinash Kaushik, Jeremy Howard, Matt Biddulph, Ben Goldacre, and Alasdair Allan and the Oxford-style debate on the proposition “In data science, domain expertise is more important than machine learning skill.” (see videos below).
Continue readingInformal notes from Strata 2012 conference on Big Data and Data Science
I’d like to say big thanks to the organisers of the conference (especially CJ @cjkihlbom) – everything went really smooth, even though there’s been 150 people attending this year compared to 90 last year.
Some points that I’d really like to highlight are:
vim is a natural choice when you’re starting a new programming project (if you’re emacs or textmate adept – you can stop reading now 🙂 If you’re starting a Ruby on Rails project there are a couple of scripts/configurations you might want to install to make development with vim an even more pleasant experience. 1. …
Continue reading “vim is the best editor, also for RoR development”
While installing new Joomla modules I came across this PHP error (yep, still have to deal with PHP occasionally). I had PHP compiled from source on Ubuntu 10.04 as per earlier instructions. Quick check of phpinfo() indicated that while gd module was compiled in, it didn’t have JPEG support: GD Support enabled GD Version bundled …
Continue reading “Call to undefined function: imagecreatefromjpeg()”
Even though there’s Ubuntu nginx package available (which works perfectly when you’re running PHP apps using FCGI), if you want to take into use Phusion Passenger, you’ll need to recompile Nginx from sources.
Instructions below were verified on Ubuntu 10.04 (Lucid Lynx) Server Edition.
Continue readingRunning Rails applications using Nginx with Passenger on Ubuntu Server