Scratching one’s itch: A post long due May 11, 2013
Posted by CK in Personal, Travel.Tags: startups, triptao
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In December 2011 I read an article by Umair Haque containing the following excerpt:
Create (something dangerous). Mediocrity isn’t a quest to be pursued — but a derelict deathtrap to be detonated into oblivion. Hence, I’m firmly of the belief that your youth should be spent pursuing your passion — not just slightly, tremulously, haltingly, but unrelentingly, with a vengeance, to the max and then beyond. So dream laughably big — and then take an absurdly huge risk or two. Bet the farm before it’s a ranch, a small town, and an overly comfy place to hang your saddle and your hat. Create something: don’t just be an “employee,” a “manager,” or any other kind of mere mechanic of the present. Be a builder, a creator, an architect of the future. It doesn’t matter whether it’s a sonata, a book, a startup, a financial instrument, or a new genre of hairstyles — bring into being something not just fundamentally new, but irrepressibly dangerous to the tired, plodding powers that be. Think about it this way: if your quest is mediocrity, then sure, master the skills of shuffling Powerpoint decks, glad-handing beancounters, and making the numbers; but if your quest, on the other hand, is something resembling excellence, then the meta-skills of toppling the status quo — ambition, intention, rebellion, perseverance, humanity, empathy — are going to count for more, and the sooner you get started, the better off you’ll be.
Whether I’m still in my youth is debatable, but two months later I resigned from my great job at the time to pursue a dream: Solving a small but real-world problem I had faced myself. There were many reasons why I didn’t start earlier, but at that point I just couldn’t ignore this sentence anymore: “So dream laughably big — and then take an absurdly huge risk or two’‘. It sounded like the right thing to do.
A few words about the motivation: It’s Spring of 2010 and soon I will travel to Madrid for a business meeting. It’s my first time there, and the meeting venue is on the city’s border in some business area with nothing to do but meetings. So I want to stay not too far from the meeting, but also not too far from the city center so that I can do some sightseeing if I get the time, or simply have a nice dinner. I will be using public transport, so I need to stay close to a subway stop. The hotel needs to be reasonably good and inexpensive (hey, I was working for a university at the time). And all that is before I start thinking about typical filters such as non-smoking rooms, wifi, breakfasts, etc. You get the drill: Madrid has hundreds of hotels, and even after applying all easy filters, I was left with more than 100 to check. It took the better part of a Sunday. Not pleasant.
The solution took longer than expected, but eventually the foundation is here: triptao.com promises to solve this problem, applying fancy math to hotel availability and geographical data. This is done using the excellent content of Booking.com, of whom TripTao is now an affiliate. Are you visiting London with its 800+ hotels? TripTao will filter them for you and show you a list in the range of 100 hotels. This is not fixed and depends on many factors, but that’s a typical reduction. I argue that if you would go through all 800+ hotels, eventually you would choose, anyway, one of those that TripTao will show you. Not only that: The ranking algorithm is also fairly sophisticated, and doesn’t take commission into account. The first result(s) to show is really those it considers to be the best. Usually, people will find their ideal hotel within the first 10 properties shown.
Now, this is not quite finished yet. Scaling down ambition was necessary to kick-off but the vision is still grand. Now that the first step is done, little by little it will get there. There are a lot of improvements in the pipeline, lots of new features planned, lots of ideas to research and implement. Hopefully triptao.com will eventually become the default go-to hotel search platform for plenty of people, and save a few Sundays for them too.
Dispatch with Scalatra on AsyncServlet January 15, 2013
Posted by CK in Software.Tags: akka, dispatch, Scala, scalatra
3 comments
A basic example of using Dispatch with Scalatra on Jetty 8.x / AsyncServlet 3.0. It took me a lot of time to connect the dots how to use Dispatch asynchronously and actually process the results (not simply return them) and I could not find examples how to use Scalatra with AsyncServlet either. So here it is for anyone who could find it useful and save themselves a few –or more– hours.
import _root_.akka.dispatch._
import _root_.akka.actor._
import org.scalatra._
import org.scalatra.akka.AkkaSupport
import dispatch._
get("/asynctest") {
// Get the AsyncContext -- or create one.
val asctx =
if (request.isAsyncStarted) request.getAsyncContext
else request.startAsync
// Execute the rest of the route in an Akka Future
val result = Future {
// Create a RequestBuilder to be used by Dispatch
val url = host("slashdot.org") <:< Map(
("Accept-Charset" -> "utf-8")
)
// Make the request, receive it as Bytes not to
// disturb binary results. Http returns a Promise
// to a result and execution moves along. More
// information on the concepts is provided on
// the Dispatch web site.
val response = dispatch.Http(url OK as.Bytes)
// Set up a handler for Dispatch' return. This
// is bound on the Promise created earlier.
response.onComplete { x =>
// Get a handle to the response and its
// output stream, we'll need this to write
// results as soon as we have them.
val res = asctx.getResponse
val os = res.getOutputStream
// 'x' is the response of the upstream web
// service
x match {
// An error occurred, the exception is
// sent to the client (of course you
// would prefer to handle this otherwise
// in real-world code)
case Left(exc) => {
os.print(exc.getMessage)
}
// Response was received with a 200 HTTP
// code, everything went fine. Data is
// written to the output stream as bytes,
// after having set the encoding to UTF-8.
case Right(output) => {
res.setCharacterEncoding("utf-8")
os.write(output)
}
}
// It is crucial to "complete" the Asynchronous
// Context, otherwise no response will be sent
// to the client.
asctx.complete
}
}
}
Big fat disclaimer: I’m fairly new to Scala/Scalatra (and the JVM for that matter), so if there are mistakes in this example –or improvements to make– let me know and I’ll correct them in the post.
Update: Ivan Porto Carrero of the Scalatra fame comments below on a much easier/concise way to achieve the same result (minor edits of my own in the code that follows but the point is the same). So it turns out you can call .complete directly on an Akka Promise, without a need to move the servlet’s asynchronous context around:
get("/async2") {
import dispatch._
import _root_.akka.dispatch.{Promise => AkkaPromise}
val prom = AkkaPromise[String]()
Http(host("slashdot.org") OK as.String) onComplete {
case Left(ex) => println(ex.getMessage)
case r => prom.complete(r)
}
prom.future
}
A new start February 14, 2012
Posted by CK in Personal.Tags: change, Exodus, greece, nephron+
10 comments
On early October 2010 I started working with Exodus S.A. in Athens, Greece, following my return from Germany. I was appointed as the coordinator of NEPHRON+, a multi-million, high-risk, ambitious EU research project aiming to help End-Stage Renal Disease (ESRD) patients with a wearable device for 24×7 haemodialysis. This period was challenging (moving in a completely new domain) and rewarding every time we achieved some next step towards this great vision. I feel grateful that I was given the chance to be part of this amazing consortium and I wish them the best of luck in the remaining two years of the project.
Tomorrow I’m stepping down from that position, ready to start chasing one more dream. I have an itch on my back that I need to scratch, it’s been there for a couple of years now and it just won’t go away. The time is far from ideal to start a company, but hey — no pain, no gain.
So wish me luck, and stay tuned for more information in the near future!
A short poll December 2, 2011
Posted by CK in IT.7 comments
I’m doing a 1-question poll. Let’s assume you can get the following web-based services, all under your own full control (domain name, private data –not “in the cloud”–, possible to export, etc):
- Intuitive wiki system supporting WYSIWYG editing and file attachments;
- TODO list management (specifically: GTD-based), possibly with Android/iPhone integration;
- Bookmarks management a la del.icio.us (without the social features);
- Standards-based calendar and address-books, that can be integrated with your desktop PIM (Thunderbird+Lightning for sure) or used over a web interface;
- Your own non-relaying private mail server (incoming + outgoing) with encryption/authentication, anti-spam controls, and Ajax-based webmail;
- Possibly a dropbox-like service;
- …and a popular, easy to use CMS for your personal web site.
All of that in a 1st-class data center with power and network redundancy.
The question is: Would you be interested in that as a commercial (managed) product, and how much would you be willing to pay per month, including email-based support?
Thanks in advance for your feedback!
Update: Just to clarify, this would be addressing privacy-concerned individuals; it is not meant to target large commercial entities, who require different levels of support and integration anyway.
Function references in Scala October 17, 2011
Posted by CK in Software.Tags: Languages, Programming, Scala
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I’m starting to learn Scala, and have some trouble coming to terms with its syntax. Maybe I’m spoiled by Python. In any case, here’s an example of things that I find annoying:
scala> def f(x:Int):Int = x
f: (x: Int)Int
scala> def g(f:Int=>Int, y:Int, b:Boolean):Int = if (b) g(f, y, false) else y
g: (f: (Int) => Int,y: Int,b: Boolean)Int
scala> def h=f
:6: error: missing arguments for method f in object $iw;
follow this method with `_' if you want to treat it as a partially applied function
def h=f
^
scala> def h=f _
h: (Int) => Int
So basically, although it is fine to use just f when defining function g, in the definition of function h it is necessary to postfix f with an underscore.
I haven’t read the language reference yet, and there may be good reasons to do it like this (although I can’t think of any right now), but the inconsistency is quite confusing.
Looking for VPS provider June 22, 2011
Posted by CK in IT.Tags: VPS
1 comment so far
The home server project is more or less over, following a power outage today. I’d be very willing to keep it always on, but if I’m to use this as a service to rely upon, I have to get such disruptions out of the way. So I’m looking for an unmanaged VPS provider, who should a) be relatively cheap, b) be relatively reliable (three 9s would be nice), c) have a/the data center in Europe, d) offer Xen with plans between 512 and 768 MB guaranteed RAM and e) allow me to install the system myself or accept ready-made images, so that I can have the disk data encrypted.
If you know of such a provider, please leave a comment here or reply on twitter at @ckotso — thanks.
My personal little “cloud” May 24, 2011
Posted by CK in Internet, Productivity, Software.Tags: Archiving, PIM data, Synchronization
2 comments
Here it is, and it works perfect:
- You will need a VPS or a home server. I’m using the wonderful, fan-less Shuttle XS35GT with a small SSD, as it is also my HTPC
- A Linux distribution. I very highly recommend Mint 10 if you’re using the XS35GT so that you get a working audio + wireless and a stable XBMC, otherwise you may wish to use an LTS release like Ubuntu 10.04 or Mint 9.
- An installation of eGroupware, to use its addressbook and calendar modules with its GroupDAV and SyncML synchronization facilities. You can easily install eGroupware using the deb repository provided on the project’s site.
- Thunderbird, Lightning and the SOGo connector to support GroupDAV. Make sure you don’t use the “SOGo Lightning” extension; at least for me it didn’t work. Then subscribe Lightning to the eGroupware calendar and addressbook. Don’t bother with TODO items, unless a flat list is your thing.
- A SyncML application to synchronize your phones. My Nokia E71 comes installed with one, while on an Android you can use the wonderful Synthesis client. Synthesis offers clients for additional platforms, but I only tried the one for Android.
- The amazing Tracks application for GTD. It takes some effort to install, but it is totally worth it. You can also subscribe Lightning to various views of Tracks exported calendars. I’ve subscribed only to the one for due items, so that they appear with deadlines in my calendar. There are also two mobile applications to sync with Tracks, one for the iOS and one for the Android. Unfortunately the latter doesn’t work yet with Tracks 2.0, but it looks like it’s only a matter of time before it does.
- …and, finally, Mindtouch Core (DekiWiki) as my data sink. There’s also a for-pay version, but I’m using the free/open-source one, which is fine. It’s also installed via a deb repository. I guess others may prefer some other platform, but for me Deki is perfect.
Then, your router set to post its address to DynDNS/No-IP or a similar service, and some CNAMEs in your domain to point to the hostname you have chosen (or simply the address of your VPS). All three services (Mindtouch, Tracks, eGroupware) are powered by Apache2, on virtual servers over HTTPS.
The data is yours!
PS: Special thanks to Yannis for suggesting to use eGroupware instead of SOGo+Funambol. A great improvement, indeed.
PPS: I only accept IaaS to fall under the term “cloud computing”, hence the quotes in the title.
Suspending a Dell 6410 w/ Mint 11RC May 20, 2011
Posted by CK in Software.Tags: Dell Latitude 6410, Linux, Mint, suspend, wpa_supplicant
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If you just installed Linux Mind 11 RC on a Dell Latitude 6410 and, while on wireless, your system crashes when trying to suspend it, try this:
sudo mkdir /var/run/wpa_supplicant
This should fix it.
Nokia going Windows. Share price going south. February 11, 2011
Posted by CK in IT, Mobility.Tags: Meego, Microsoft, Nokia, Qt, Symbian, Windows
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Not much to say about this. One only needs to read the comments of developers following the announcement that Nokia completely "changes strategy", hand-to-hand with Microsoft. I guess most people expected that, ok, Nokia will test the waters and develop some Windows devices. Or at least that was my assumption. Unfortunately, such close partnership is quite reasonably expected to kill Symbian (which would be ok IMHO), Qt and Meego altogether. Microsoft is not known for its affection towards competitors. The PR talk by Nokia is not convincing.
I guess, it’s not only developers who are not convinced. During the day, Nokia’s share price in the DAX fell by some 14%:
At NYSE, as we speak, the share price falls by some 16%:
Clever move to go Microsoft, guys. Everyone has lots of faith in this, as you see.
The upcoming WebOS ecosystem February 10, 2011
Posted by CK in IT, Mobility.Tags: Android, HP, Meego, Nokia, Palm, WebOS
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I was particularly impressed by the HP announcements yesterday, that in addition to a couple of new phones and a tablet based on WebOS, it is also planning desktops/notebooks with the same OS. The main reason being, HP seems to be the second behemoth in a few days that realizes the obvious: Offering a complete ecosystem attracts developers; and a large range of applications attracts users — given, of course, a decent OS in the first place. Apple did this and has been winning the race so far. Microsoft does offer an ecosystem as such, but it doesn’t seem capable to capitalize on it, presumably because the platform/OS itself is not good enough. Android is apparently managing very well on the mobile world, but Google’s proposal on the desktop, ChromeOS, does not integrate on a development level (even though Google’s services make up for that to a large extent). Although this does not hurt Android-phones sales, I believe it is only due to the fact that Android is an open system, so phone manufacturers feel safe to base their businesses upon it.
I really think that WebOS can remain (become?) one of the big players in the future, given this new strategy of HP, its deep pockets, and the system’s quality. If I was a developer, I would be more than happy to create applications for this platform — especially if they have "write once, run everywhere" properties with as little customization as possible.
Hopefully, Nokia will also build on a similar strategy with Meego — even if it must divert towards Windows/Android for a while, to keep the stock holders happy. It would then have the additional advantage of offering an open platform (like Android is) to attract other manufacturers, but compete on device quality where it shines. Revenue from desktop H/W sales would be a bonus.
