Git 101: How to Handle Merge Conflicts

In the last post, I talked about how to create a Git repository and upload it to GitHub. In this post, I’m going to talk about how to resolve Git conflicts.

Setting Up Our Environment

First, we’re going to create a Git Repository for the user Doug. Since I already covered that in the last post, I’m bring to breeze through those steps below:

$ mkdir doug
$ cd doug
$ git init
Initialized empty Git repository in /path/to/doug/.git/
$ touch README.md
$ git add README.md 
$ git commit -m "First commit"
[master (root-commit) d86a7e2] First commit
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 README.md

At this point, we have a repository created for the user Doug. Now I’m going to clone that repository for the user Andrew:

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Git 101: Creating a Git Repo and Uploading It To GitHub

In this post, I’m going to discuss how to create a GitHub repo and upload (or “push”) it to GitHub, a popular service for hosting Git repositories.

What is revision control and why do I need it?

The concept of revision control is a system which tracks changes to files. In programming, that is usually program code, but documents and text files can also be tracked. Using revision control will give the following benefits:

  • You will know what was changed, when it was changed, and who changed it
  • Multiple people can collaborate on a project without fear of overwriting each others’ changes.
  • Protection against accidentally deleting a critical file. (revision history is usually read-only)

In GitHub, we store revisions in “repositories” or “repos” for short. As of this writing, the #1 service for storing Git repositories is GitHub. They offer free hosting for Git repositories.

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Notes from “Scaling on AWS for the First 10 Million Users”

Earlier tonight, I had the pleasure of attending a presentation from Chris Munns of Amazon at the offices of First Round Capital about scaling your software on AWS past the first 10 million users. I already had some experience with AWS, but I learned quite a few new things about how to leverage AWS, so I decided to write up my notes in a blog post for future reference, and as a service to other members of the Philadelphia tech community.

Without further preamble, here are my notes from the presentation:

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An American’s Visit to Sweden and Denmark

I found myself between jobs a short awhile ago, and suddenly had a few weeks of downtime. Since I had an open invitation to visit Sweden and Denmark from friends living there, I figured I would take the opportunity and head over. I took a few pictures, and noted some observations about those countries.

First, Know Some Locals

If you want to take a package tour and see the parts of the country that are tourist attractions, feel free. But you’ll get much more out of the experience if you know locals who can show you things that they think are interesting. I was fortunate to know both Pinky Fennec and Joel Fox, who were more than happy to host me while I visited.

Public Transit is Amazing

Subway Station
A subway station on the Hågsatra line

The train system in Stockholm is pretty extensive. Trains and busses run pretty much everywhere you’d want to go. Both systems used a wireless card that you could buy with a week’s worth of fare, and just swipe it at the turn style or at the front of the bus. Subway stations had displays above the tracks stating how much time until the next train would arrive. When bus schedules said that busses arrived on the quarter of every hour, they meant it.

It was also pretty much the same in Copenhagen, except I spent more time on busses. The bus service there was simply phenomenal. They had busses that would arrive every 8 minutes, and they meant it. I regularly commuted from a friend’s place on the outskirts of Copenhagen to the central part of the city every single day.

Getting from city to city was also fun. I rode on what amounted to the Swedish version of Amtrak from Stockholm to Copenhagen. It was a single train ride, about 400 miles in 5 hours. That’s an average of 80 mph, but with the stops we made I’d say we did somewhere between 90 and 100 mph most of the time. The train ride was exceptionally smooth, and several times when we started moving I thought that the train next to us was moving. Naturally, these trains were also on time.

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Multi Core CPU Performance in GoLang

I’ve been playing around with Google’s programming language known simply as Go lately, and have learned quite a bit about concurrency, parallelism, and writing code to effectively use multiple CPU cores in the process.

An Overview of Go

Pictured: Not A Serial Killer

If you are used to programming at the systems level, Go is effectively a replacement for C, but also has higher level functionality.

  • It is strongly typed
  • It can be compiled
  • It has its own unit testing framwork
  • It has its own benchmarking framework
  • Doesn’t support classes, but supports structures and attaching functions to variables instantiated from those structures
  • Doesn’t expose threads, but instead uses a construct called “channels” for communication between different parts of a Go program. More on channels shortly.
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Running Dorsai Thing 2013: Lessons Learned

The Liberty Bell

Each year, The Dorsai Irregulars have their own annual convention known as “Dorsai Thing”. It is a weekend long event, held in a different city each year, where we all gather, socialize, and hold our semi-annual business meeting. This year, it was held in Phildelphia, and it fell on my shoulders to run the event, dubbed “Liberty Thing” While I’ve worked at plenty of conventions before, this was the first one where I was effectively the Con Chair. This was an entirely new thing for me, and I wanted to write a blog post about some of the things I learned during the experience.

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Setting up IPv6 on Linode with nginx

So Linode has gotten onto the IPv6 bandwagon. In addition to each Linode getting an IPv6 address, they will also gladly assign an entire /64 netblock to your specific node on request. That gives you all sorts of flexibility for bringing up IPv6 services. And this blog post is going to be all about how to make use of multiple IPv6 addresses.

As of this writing, everything I mention will work on a Linode running Ubuntu 12.04 LTS and Nginx 1.1. There’s no reason that these instructions shouldn’t work on other distros or versions of Ubuntu with some modifications.

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Scaling Anthrocon’s Website to Handle 1,400 Simultaneous Connections

The Challenge

When hotel reservations open, that is the single busiest time of the year for Anthrocon’s webserver. In fact, it even caused us performance problems last year. That was not so good.

So this year, I decided to try something different. Instead of leaving the regular website up and running, which involves using Drupal, I instead decided to replace the entire page with a relatively static “countdown” page, which displayed a countdown timer and automatically started displaying the hotel link at 11 AM on the opening day.

First, some stats for the Anthrocon website:

  • Peak bandwidth: 1.6 Megabits/sec
  • Peak connections: 1,400 concurrent connections

And now some status for Passkey, who handled most of the traffic:

  • Peak bandwidth: 190 Megabits/sec
  • Peak connections: 4,000 concurrent connections
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If I get hit by a beer truck

…please read this web page.

This page is here so that if something happens leaving me in a state where I am no longer able to run my websites, people will know what to do.

Danish beer companies employ the absolute worst drivers.

While I have no plans of buying a farm anytime soon, sometimes accidents and sudden illness happen. That also means that if I am in a persistent coma of some kind, or have a terminal condition, please don’t keep me on life support for months or resuscitate me–just let me pass on peacefully.

I designate Samuel C. Conway, PhD as my virtual executor to organize such things. In the event that Sam is not available, then I designate Tom Geller as virtual executor. They’ll know what to do, or know people who will.

All my websites – Including (but not limited to) this one, IsSeptaFucked.com, and SeptaStats.com, Sam (or someone he designates) should be the new webmaster/site admin. Please keep the websites operational where possible. Where appropriate, pages should contain a note about what happened. Please update this page with a link as well.

Source Code – Anything that is publicly available on my GitHub account should already be available under an open source license. If it’s not, please assign the copyright to the Free Software Foundation. They seem pretty chill about letting people use their code.

Funeral/Grave – My family has a series of plots purchased in a cemetery, I will leave it to them to bury me there. I expect something about cheetahs written on my tombstone. I mean it! While friends are welcome to come to my funeral, I’d rather have a Celebration of Life held weeks/months after my passing so that friends can travel from further distances to attend. A hotel would be an ideal spot for this. Having alcohol on hand for guests would be a really good idea. I expect my friends to laugh, cry, and damage their livers while telling stories about me.

For anything else, contact Sam or Tom.

Oh, and I’ll miss all of you. Even the cheetahs.

Updates:

  • 1 Apr 2017: I’m not dead yet! (and that’s no joke)
  • 15 Dec 2018: Moved the website over to WordPress, and I’m still around!

(Based on Aaron Swartz’s page)

I hate pennies. I *really* hate pennies. What to do with them all?

I really hate pennies. Let me count the reasons:

Here, look at my pile of spare change that I’ve collected from the last few years:

I really hate pennies

Just look at it. Half of that pile is pennies! The pile of pennies is worth what, $5? $10? The pile of nickels and dimes on the other side is probably 7 or 8 times that. I seriously think that if I take that many pennies into a bank to deposit that the security guards will shoot me just on general principle. Can’t say I’d blame them.

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