We started using MixPanel to get realtime statistics on user engagement in our application. We’ve been using MixPanel before for funnel tracking, but you can’t really appreciate their service until you start using their event tracking. It is truly realtime (as advertised) – the second the user performs an action on your application, you see it on your dashboard.

Besides the realtime reporting what I really like about MixPanel is the fact that they allow easily reporting from your backend and not only from frontend/Javascript (as opposed to Google Analytics).

Within their documentation they have code samples in many languages, including Python. But their Python sample requires ability to start new processes on the server you’re running – something not possible on App Engine. Therefore I changed it to use URLFetch in RPC mode (so that calls to Mixpanel won’t block the call):

It could be re-factored more, like allowing setting the project token outside the function call, but that I will leave for you to do (and if you do, please share with us)

Arik

1. splitting user requests into two pieces – one that being done immediately and one that being done in the background, to speed up the response time.
2. mapping (iterating over) all my entities to calculate various statistics.

I won’t provide here details on how to use deferred tasks, because this is described in detail in a great article by Nick Johnson, which I highly recommend reading. One thing I do want to share from my experience, is my implementation of the Mapper base class:

This implementation is taken from Nick’s article mentioned above, but I made some changes to it. The first change is giving subclasses the ability to set the property to order the entities by. I needed this, because I found out that when your entities have custom key names ordering by key breaks for some reason.

The other change is re-factoring the way the next batch starts. It seems to me that in the sample provided in the article there’s an error in the indentation, resulting in the code not doing batching properly and can even break in some situations. In my version every task run maps only one batch (or less). This is sub optimal in terms of # of tasks it takes to map all your entities, but as long as you don’t have really a lot of entities this is not such an issue.

I really would love to hear others’ comments no my changes and about how you use deferred tasks or map your entities.

Arik

I’ve been doing quite a lot of Facebook development in the last few months. At first I was using my own account to do most of the testings for the apps I was working on. I always have (at least) two versions of the app – production and development. The development version is marked as sandboxed, so any action I do in it (including posting to the newsfeed) isn’t shown to my friends.

At first I felt that this is enough, and didn’t feel the need for a test account. But after some time I realized that while developing, anytime I get to my profile or newsfeed, I get distracted by my friends’ posts. So I started using another account to do the testings. This way, whenever I get to the profile or newsfeed I practically see nothing there that can distract me from what I’m working on.

Another benefit of using a test account is that whenever you test something on the production (un-sandboxed) version of your app and need publish a lot to your newsfeed, you don’t spam your friends (or reveal upcoming features).

Of course, we can rely on our self discipline to avoid this distractions, but who are we kidding?

Arik

This is another way to protect your software - just ask politely. (Photo by penner42 on Flickr)

A friend of mine sent me this question by email today:

I have  a software written in visual C++ which is compiled into an .exe file and I wish to distribute (sell) it in a “secure” (anti pirated) way.  How can I “lock it” so it will be able to run on only one computer (the one of the person who purchased the software)?  Is there a software to turn .exe files into protected ones, or good tutorials on what to do from the coding side?

I thought that for the general good and in order to get more views on the topic, I will post my answer to him here:

I can think of mainly four ways to protect your software -

1. Some serial number authentication mechanism – this is the most traditional way and it fails big time. All of the documented techniques to protect yourself in such a way are already broken, and if you’re not in the field of software security you probably won’t find anything better. This might be a good way if you know that your target market is non-technical people who probably won’t bother breaking your authentication mechanism themselves and usually don’t know someone who can do it for them.
2. Serial number authentication and online check – this is what Babylon do. When their application connects to their server it verifies the serial number it has with their database, if they see some misuse they either lock your application or just stop providing you answers. Microsoft use similar technique with XBox Live accounts – whenever you connect to XBox Live they check if the games you run are legal – if not they take actions against you. In recent check they disabled 1 million pirated accounts. But not only they disabled their access to XBox Live, they also disabled the hard drive in their console. This is quite good method as long as your software requires constant communication with your server. If not there are ways to override this protections (like disabling access to the Internet from your application).
3. Good target market – like in mentioned in (1) a lot depends on your target audience. If you create a truly great product and price it in reasonable and achievable price, most people are likely to pay (unless your target solely to the Israeli market…).
4. Online service – if you convert your software into an online service (like the 37Signals products, ZoHo, GitHub and many more), you are fully protected up to the extent that people will use stolen credit cards or hack your system in some way. But this actions are considered as “real crimes” by most people and they will less likely use them or spread the knowledge about them.

This are the four ways I can think of. If you ask me what would I do, I would go with option #4 – all other ways (besides #3) require you to invest unreasonable time and money in protecting your software instead of improving it. While it can be a nice mouse&cat game, it highly unproductive.

That’s what I think, I’m not sure if it really helps my friend, but maybe one of the readers will offer some better insights & tips on the topic.

Arik

Just read on TheNextWeb that Facebook is about to allow users to switch from profile urls like http://www.facebook.com/profile.php?id=1234567890 to http://www.facebook.com/username. Awesome, right? They will open up the registration on Saturday, June 13. On the registration page there’s currently nothing, but a countdown until registration is open.

If you have a common name and you’re afraid that your username will be taken (like I do), you probably want some alert before the countdown reaches 0. Well, that’s exactly why I created the @fbname Twitter bot.

Just follow @fbname and it will DM you 1 hour before the registration of vanity urls is actually available on Facebook.

Enjoy
Arik

PHP Wrapper for Mr.Tweet’s V1 API
API Doc: http://api.mrtweet.com/v1/docs

It uses libcurl and requires PHP 5 >= 5.2.0 for json_decode.
Of course, you can rewrite to use other json decode funtions (or SimpleXMLElement for the XML response) and something
different than libcurl.

While it very straightforward, see MrTweetApiTest.php for example of usage.

Used originally for Topify (http://topify.com/).

Their API is in alpha right now, so you need to request an API key by emailing api@mrtweet.com.

Would love to hear comments and to see people forking it!

Arik

And now you can do :

arikfr:~ arik$ curl -i -X BREW http://topify.com/
HTTP/1.1 418 I’m a teapot
Date: Wed, 13 May 2009 08:51:07 GMT
Server: Apache/2.0.59 (Unix) PHP/5.2.6 DAV/2
X-Powered-By: PHP/5.2.6
Content-Length: 29
Content-Type: text/html

We do serve ICE Tea, though.

It’s not as elegant as Ruby code or Ruby gem, but it does the work.

If you use this on your own server, please ping me. I would love to hear