Very good interactive Git workflow cheat sheet

Few minutes ago I was looking for a Git workflow cheat sheet to verify some rarely-used parts of my knowledge before doing something I might regret. Actually I was hoping to find something very simple (preferrably one pdf page or so), but instead I found this one, which is a very good, interactive webpage. So I decided to share this find with you, because it’s definitely worth it:

http://ndpsoftware.com/git-cheatsheet.html

Git workflow cheat sheet

Git workflow cheat sheet

What’s best in it, it presents everything in a very intuitive, visual way which is easy to understand. If you are looking for a command which will completely revert your commited changes, you can just click on “Local Repository” and see which arrow points to “Workspace” – it’s a git reset --hard one. How about leaving the changes you’ve made, but reverting commit? It’s an arrow with git reset --soft. Brillant!

It’s not only a good thing for people who look for a typical cheat sheet, but also for those who have some problems with understanding git workflow.

I really like it – nice work guys!

More on Cassandra’s SimpleAuthority permissions

Few days ago I had some doubts on how Cassandra’s SimpleAuthenticator and SimpleAuthority really work. I mean – I was not sure of the way I should configure them to get the expected results. It may seem obvious now, but I had to look at source code to find out what is possible and what is not. So, to save your time, here’s a brief description of this.

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My first Cassandra contribution

A bit surprisingly and somehow accidentally, today I became a Cassandra contributor. I had a problem with the project I do for work, which made us unable to make our bulkloading script work together with Cassandra authentication (which I described in one of the previous articles on this blog), so we decided to try solving this issue on our own.

The solution was quite simple, but gave me a bit more of Cassandra knowledge and understanding. If you are interested in contributing to Cassandra I think you can take a look at this problem and the solution or even try to reproduce this problem (on Cassandra 1.1.0-rc1 or earlier) and then try to solve it on your own. As I said it was simple, so you won’t get frustrated with the problems you will face, but I think it’s good start for something more. Here is the link to Cassandra’s bug tracker issue:

https://issues.apache.org/jira/browse/CASSANDRA-4155

Working on interesting things, being nicely paid for this and contributing to remarkable Open Source projects in the same time – could it be any better? ;)

Adding simple authentication to Cassandra

Today I was asked to set up user authentication in Cassandra, so we could stop using the “default” user with unrestricted access only. I have to say that I was really surprised when I noticed that there’s NO out-of-the-box authentication and authorization framework in it. Luckily, it can be easily enabled in a few steps which I’m going to show you.

One important thing – SimpleAuthenticator we’re going to use is in the “examples” directory of Cassandra package. It’s because it is considered to be very simple and not very safe (it was even called a “toy” in one of Cassandra’s Jira tasks), so DO NOT rely on it as on a serious protection tool for your system. However it still fits many requirements (i.e. you don’t want user to make a mess in a Column Family he doesn’t need to work on) so you may find it useful. You have been warned.

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