Linux Shell Output Redirect

If you like to run a program in total silence and write every output to a file of your choice use:

YOURCOMMAND &> YOURFILE

This will redirect everything to the specified file.
Helps for cronjobs or huge output generators like Hadoop.

CouchDB Lucene: Connection refused

Yesterday a got the following exception from my couchdb:

Traceback (most recent call last):
  File "/opt/couchdb-lucene-0.7-SNAPSHOT/tools/couchdb-external-hook.py", line 40, in main
    resp = respond(res, req, opts.key)
  File "/opt/couchdb-lucene-0.7-SNAPSHOT/tools/couchdb-external-hook.py", line 81, in respond
    res.request(method, path, headers=req_headers)
  File "/usr/lib/python2.6/httplib.py", line 914, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib/python2.6/httplib.py", line 951, in _send_request
    self.endheaders()
  File "/usr/lib/python2.6/httplib.py", line 908, in endheaders
    self._send_output()
  File "/usr/lib/python2.6/httplib.py", line 780, in _send_output
    self.send(msg)
  File "/usr/lib/python2.6/httplib.py", line 739, in send
    self.connect()
  File "/usr/lib/python2.6/httplib.py", line 720, in connect
    self.timeout)
  File "/usr/lib/python2.6/socket.py", line 561, in create_connection
    raise error, msg
error: [Errno 111] Connection refused

Because it worked like a charme for six month until now, I got pretty depressed. To solve the issue a begun to randomly search the web for this stack trace of my lucene view. But I could not find anything useful until now. After reading the third tutorial about how to setup lucene with couchdb, I figured out that the couchdb-lucence is not running anymore. Therefore after restarting the couchdb-lucene daemon everything works fine again.

Just execute this to start your couchdb-lucene again

    nohup /opt/couchdb-lucene-0.7-SNAPSHOT/bin/run &

Real-Time measurement in C

For those of you, who could not find it somewhere else.
Here is the code snippet to get time measurements exact to  the microsecond on a Linux system with pure C.
Fun fact, the struct is already there, should be defined in time.h
rt_printk is real-time printf to read your output use command dmesg

#include 
#include 
#include 
#include 
 
int main(void)
{
 char buffer[30];
 struct timeval tv;
 time_t curtime;
 gettimeofday(&tv, NULL);
 curtime=tv.tv_sec;
 strftime(buffer,30,"%m-%d-%Y  %T.",localtime(&curtime));
 rt_printk("%s%ld\n",buffer,tv.tv_usec);
 return 0;
}

Social Networks and Academic Research

The world is getting faster and faster, but still the most reputation in research is in printed journals.
Now it seams that the times change. There is an upcoming development of social networks for researchers.
These are not like Facebook with sharing pics and useless stuff to procrastinate. Instead the research networks focus on publications and the answer of small research questions in collaborative manner. (see also German Article of Welt-Online)
So check it out, it might become an advantage soon.

researchgate - Social Researcher Network (German startup)
academia - Social Researcher Network (US version)
mendeley - Collaborative Paper Plattform

Start of an idea - Eclipse Badges

Do you ever coded day and night without having enough benefit from it. Here it comes the Eclipse Badges Extennsion. Okay, it is not yet developed, but the idea is cool and to cool to die.

So here some bullets for what you could earn badges while coding:

• X hours coding at once
• Master of Shortcuts
• Challenger of Refactorings
• Best Refactorings in a Row
• longest class name
• Deepest Hierarchy
• lines of code per minute
• longest method
• deepest call hierarchy
• Quick-fix Master
• Web of Eclipse (a lot of complex dependencies)
• longest build time ever
• Antitrust, Eclipse as notepad
• Archaeologist open the oldest projects
• Plugin Master - you can catch them all
• most active views
• nightly coding is appreciated
• Your Rank as developer in the Eclipse Badge Community

All this stuff is coming soon...

Please comment for more ideas!

German Museum of Technology in Berlin

I am currently taking part at the Wissen und Macht symposium in Berlin. While presenting some fact about my university and about the Blog-Intelligence project, I can listen to diverse talks about the power and oppurtunities of the web.
Hereby the main interest is in improving the quality and distribution of knowledge. The message is that universities and online communities shall interact more to build a trustful knowledge base.
One contra point mentioned is that this will make the web more inklusive, so normal people like you and me without an reputation will get problems.

The important point discussed now is the influence through social media and especially through the blogosphere. For example a journalist presents the Egyptian Blogger phenomen.

Check out the homepage and the Tele-Task for more information and streams.

Setting up a new notebook

Hey Guys,
I am just setting up my new notebook. Business as usual, installing the same stuff and configuring it in the same way as before.

I found a nice tutorial for transfering your putty configuration from one pc to another Link to Tutorial.
So you just have to know the right registry key, export it and all your ssh config is back.

Citations of The Day

For the Beginning of this semester my citations of the Day

"Misquotation is, in fact, the pride and privilege of the learned. A widely read man never quotes accurately, for the rather obvious reason that he has read too widely." - Hesketh Pearson

"Men who seek happiness are like drunkards who can never find their house but are sure that they have one." - Voltaire

"A weak man has doubts before a decision; a strong man has them afterwards." - Karl Krauss

"No one on his deathbed ever said, "I wish I had spent more time on my business."" - Arnold Zack

Trip to Florida

Guys, I just went to Miami for vacations. It was an awesome trip. Let's begin! 

First, we arrived in Miami. So warm, unbelievable compared to the ultra cold AC of the plan.
Directly to the Miami International Hostel, just 500 meters from the beach. And the beach was nice. White, long and lots of ladies around there. We've been a bit unlucky with the weather, so cloudy and some strong rains.
Nevertheless, chilln around the beach promenade can be expensive, but it is worth it. Lots of bars and a quiet busy place.Next, we went north. Titusville, nice motel Daysinn nearby. And there it went to Space, Cap canerval, Kennedy Space Center. Pretty awesome to see the rockets in real life, I can recommend the rocjet garden and the cap tour with the launching pad. A pretty nice simulation of the moon landing and of a apollo launch are definetly a must see. All in all: a filled day.
Next station Orlando with all his Theme Parks. First Sea World, incredible cool animal shows with dolphins and orca whales. Including some awesome roller coaster trips. Next day, next park, Aquatica, an chilled water park with swimming, sun bathing and scary slides. And finally on the last day in Orlando, we visited Universal Studios park. It felt like being in a movie, really nice rides with fire and other stunning effects. Including the Mummy ride and the white shark boat trip. Pretty cool.

Next up to the best beach ever Siesta Key. Rip currents all over, really scary but we managed it. After a swim and a long beach walk we continued to the Everglades national park. Simply impressing nature, all over the place. We made a nice boat trip and the guide explained us everything about all the plant and crocodiles. Next day we made a cool cycle trip through the park and chilled in the evening in the Hard Rock Cafe Miami beach.
And finally we went for a trip to Key West. All in all a nice sleepy pirate village with a quiet good bar mile and an awesome sunset.
So far the sum up of 12 days Florida.
See you in the sun!

Creating a Data centric website

Hey Folks,
I am just starting to create a data-centric webapp. The main goal is to allow the user to discover an huge dataset.
Therefore I am currently searching for diverse libraries. Here some early results:
Post on Highcharts JS
Post on JS Charts
Article on Accessible Data Visualization
Post on Google Chart API

To sum up, Google Charts seems to be the fastest solution, but only enough for a prototype. For an highly interactive and discoverable chart I will dive into Highcharts and js chart.

Stay tuned!

Apache Nutch and I

Hey Folks,
I just started to working with Apache Nutch during my studies. Seems to be a quiet sophisticated spider/search engine. So it might apply perfectly to the blogIntelligence-project I currently working on. Let's see. Nevertheless, it's an official part of the Search Engine lecture at HPI so I will have to get along with it.
So I decided to make an extra blog on nutch check it out.

http://nutchinprogress.blogspot.com/

How to negotiate with Auto drivers a.k.a. rickshaws a.k.a. tuc tucs?

First of all it's everytime useful to be prepared. So, check with some friend for the usual fares or check on google maps for the correct distance to your location to estimate the meter price (currently 8 INR per km, min 19INR). In addition if you have plenty of time in advance it's quiet useful to learn the local language like Kanada for Bengalore, if you able to speak than you mostly get the correct price (even at night time you will be able to make the best deals).
Nevertheless, don't worry if you have no idea of the destination or language, you still able to make a good deal.
So let's begin, go to the street and wait for a rickshaw, if you now the direction wait on the appropriate site.
Clearly avoid to go to non-police driven rickshaw stands,the rickshaw drivers  there do not act like independent competitors like the drivers you will find on the street. They will act as an overpriced collectiv with nearly no negotiation. Instead you should prefer to stop a rick or go to some police-driven prepaid rickshaw stands like the one at Bricade / MG Road.
Check the frequency of rickshaws to decide whether you can effort to wait for another one. It's always better to plan a bit more time because it's always possible that especially at nighttime it takes time to find a rickshaw or that a rickshaw driver don't understand the correct destination or a driver takes you for a roundtrip.
When the rickshaw driver arrives the best tactic is to say only the location and when the driver confirms directly enter. Usually the driver will automatically start the meter if it's daytime and begin to drive. Otherwise you have to ask for meter, at daytime you should not agree on anything else.
In the case a driver ask you for a certain amount you have to bargain. To know the target of your negotiation it's usefull to know the distance/normal price, otherwise you only possibility is to achieve like 40% of the requested price. So if a driver ask you for 50INR the normal price is hardly around 20INR. But be aware of drivers asking for immense amounts like 400INR this prices are not even applicable for the longest ride you can take in BLR, so go for 100INR. The drivers are using lots of legends around the law and police to get extra charge from you.
Only 3 guys per rick -- There is the legend that rickshaws are only allowed to take 3 people otherwise the police will charge them a fee, this never happens for my time here in India and none of my friends ever experienced this, so do not take it as any argument.
Double meter at nighttime -- The nighttime fare starts at 10pm and is about 50% more, so one and a half meter. Do not believe any other stories they wanna to tell you like double meter or nobody will be there on driving back.
So the golden rule is to stay near your targeted price, stay friendly and keep on arguing. Should the driver not come near to your desired, you should try to find another rickshaw (even the attempt will shrink the price). And don't worry, the next driver will even be easier to negotiate, because he already realized that you do not take any random price.
Although, a rickshaw is going by meter, one has to be aware of faked and very fast meters. So it's quiet useful to know the distance or at least own a feeling about how much is one km that you can check if everything ticks the right way. In addition please watch out for roundtrips, tuc-tucs tend to take longer ways as usual to get more money out of you. So even if you not knowing the way and get some deja vues, just tell the driver to go straight to your destination. (it's worse to risk a bad feeling if he didn't cheat on you).
Any price you aggreed with your driver is fix and no circumstance can change it. Even if the driver did not clearly understand the location and therefore take a roundtrip, you have to clearly refuse to pay more. Same for adds to the meter price such as entered nighttime or 4 people and so on.
In general, you should always stay patient and calm to rickshaw drivers, avoid harsh and loud language and do not make yourself any stress it is not worth it.

Wayanad in the north-east of Kerala, India

I went for a trekking trip with my buddy Chadha and some of his friends to the green hills of Wayanad.
I was pretty excited before because I never went to trekking before. So, I went out and bought some stable shoes to be prepared for every possible terrain, which was a bit too much, but I like the shoes.
I was pretty keen one being on time, so I slept by a friend in whitefield. Actually, the trip should start at 7am in the morning. But as I called my Indian friend around 7 he sounds quiet sleepy. Nevertheless, they handle to pick me up after some time. We rent a private cab for our trip, we were around 12 people so quiet good for a cab. Just after entering the cab a felt asleep as everybody else. After 2-3 hours we reached our first stop at an highway restaurant, where we had typical Indian breakfast with dosa, igly and chai. Then we continued driving and reached a hill near the border of Kerala. One could see an amazing green landscape with one small temple on the top. At that time there was something like a public lunce where everybody get's some food at the temple. My friends and I didn't attend instead we made lot's of nice pictures and explored the surrounding by small tracks. One guy brought a cowboy head which made quiet descent pictures possible.
Short before we left there came a very dense fog, which restricted the view to less than 50m. Due to this, the ride back down the hill became a quiet big adventure for me, although the driver felt appearently pretty comfortable.
The next stop was at the border of Kerala where we have to pay some route tax and stopped for a nice chai. There was a nice rice field in an amazing clear green and more over a huge rickshaw transporter carrying a bunch of brand new tuc tucs.
After we stopped for some lunch, we arrived at Wayanad after sunset and searched for a stay. We found a stay by talking to some locals which are looking after the house of rich families and rent it during their absence. We got a quiet descent house with two stages, shower out of the bucket and a TV, so more than needed for a two day stay. After fixing the location we searched a bit for boose and watched a cricket game at the house.
The next day we stand up quiet early to get around Wayanad. We visited a small lake with some even smaller boats and a nice waterfall, which was quiet a challenge to reach. So a pretty hard track at least for an untrained German guy, but one get some pretty nice pictures of the mass of falling water.
After this exhausting trip, we get back into on the street cruising around. Than we saw some tea fields, and stopped for making some nice green pictures. Afterwards, we went to Asia's second biggest dam with the biggest human created lake. The funny thing about it, was that we went for a boat trip around the lake, with an speedy boat and I recognized that most of the Indian guys are not used to so much of water. As difference in Berlin you go for a swim or a boat ride whenever you like.
 The next day we went back to Bengalore on the way we stopped in Mysore checking out the zoo. Man, this was so crowded unbelievable, only comparable with the so in Berlin while this small polar bear baby was around. Despite from the funny warning on every cage and fence (like "These who throw objects at the crocodiles will be asked to retrieve them!!"), it was a bit sad, because most of the animal looked not ill or unhappy.
Nevertheless, after a short look at the closed palace we finally left to BLR.
To sum up, a wonderful trip around green nature. Thanks a lot guys

India: daily life

The last post is longtime ago, so one short sum up from my life since the move to Koramangala.

My roommates are awesome. Currently, one french guy, one South-African guy, two Spanish ladies, one polish lady and my Swiss land lord. A very good mix. 2 weeks Sandra, a German student, left to France. Totally crazy girl, bargained with the rickshaw driver over each single rupee.
Via Sandra, I met Jo, one really cool Bavarian guy, who lives in Whitefield and works near by SAP.

As one can imagine, already well before Sandra left, we began to make countless farewell parties. Went to different places in the centre of Bangalore and has some line breaking house parties.
Where I met so many cool Indian guys, not only from Bangalore's IT industry, but also from different colleges and universities. Really crazy people.

Nevertheless my daily life in Bangalore is quite the same during the last few weeks. In principle, I stand up at 6.30, take a shower, and run for the SAP shuttle, which is always a really tight time plan for the morning, because the shuttle leaves at 7.20 and I like the snooze function of my alarm.

40min later, I arrive at SAP Labs India, and goes to my working place. Here I normally check mails and read some news till 9 o'clock. Afterwards is breakfast time combined with a short walk. Than the real working time starts for 4 hours, afterwards lunch break with throughout good, but sometime boring, Indian food. It depends on the daily workload and mainly one the daily effectiveness of mine, when I will leave. My leaving times in the office vary from 17 o'clock to 9.30. Another influence factor is, whether there are any leisure time activities scheduled, like hanging out in the city centre, make some TV watching season at Jo's apartment or cool dinners at my place.
On Tuesday, I helped the French guy to prepare crepes for the whole house. Delicious!!!
And Coni (Swiss land lord) was not so excited about the bunch of dishes lying around in the kitchen.
So, all in all, I'm totally into chillin' after a hard working day and finally, I go to sleep approximately 1 o'clock. But one can never predict what happens next in Bangalore so stay tuned.

By the way, I am still trying to buy a bike or a bicycle..., but on searching half-assed one will not find any cool offer. So I have to hurry up.

India: Bangalore Koramangala

Größere Kartenansicht

 Here, I am living for the time being. First Block Koramangala, very nice and silent place. There are lots of small restaurants, a very good connection to the BMTC bus system, many small shops, good supermarkets, ...., I like it.
It is now my second week in Koramangala. I can highly recommend this place.
Sony World, AlienWare Shop, a very nice small Punjabi restaurant, Sunis Laundrary (40rupees per kg) and there is more to come.
Koramangala is also a kind of a student area, many young people living here. So, bars and cafe are always well patronized.

In detail, I live in one room, which is part of a four-room guest house. Sharing kitching, living room and shower with my room mates. They originate from all over the world, Spain, France(maybe), Germany, and Russia. In addition our land lord is a swiss photograph. For Indian standards, this is a very cool place, but for an European there severall things, one has to arrange with.
Including the Indian manner of using the toilet, ..., there is no toilet paper at all, just a min shower.... But I am willing to learn. One also has to mention, that we have a very cool garden where one can take severall sun bathes. As contrast, there is one of these special Indian rivers nearby, so keep an eye to the wind direction.

One of Bangalores rivers

India: Bangalore Whitefield

After three weeks in Bangalore, I love this city. All in all it is totally amazing. This city has all sights of India concentrated to one big melting pot of cultures and social ranks.
I lived for the first two weeks in a service appartement at Varthur Road, Whitefield(the place to be for IT guys). Nearly every global player has settled down in Whitefield or Electronic city. As contrast all cool places like the MG road, the student area Koramangala are at least 40min apart. Although, there is everything what you need for your daily life. So if you only use Bangalore as your base to make journeys all over India and you go for an internship to an IT company, that's the place to stay.
Check out Hyper City, Forum Value Mall, Sportsbar, and a good bar between Dominos Pizza and Cosmos Mall. I hope, I will find it in the next few days and figure out the name. To sum up everything is around, just have to know where.
As mentioned above, one need 40min to reach the city centre by public bus. But attention, the rickshaw driver in Whitefield know that every guy here is working for an IT company, and so they will try to cheat you. So, I think it is cheaper to take a taxi or the bus. Another amazing fact, buses are the faster vehicle in Bangalore, I assume that is because they are the strongest vehicle and get the priortiy in this crazy traffic.

India: first impressions

After the completion of my bachelor degree at the Hasso Plattner Institute (Potsdam, Germany), I went to India for an internship at SAP Labs Bangalore. So, I am here for nearly one month now and I like to sum up my learned lesson and my first impressions of Bangalore. Here part one.

First, do not trust any body who comes to you and want to guide you to a taxi, a shop or anything else. These guys will definitely cheat you and charge you more than ten times of the normal price. For this reason, before coming to India alway talk with some Indian friends, contact some Indian colleagues or read some Indian tourist guides.

A fact, which would save me a lot of money is, that per km the price for a taxi never exceeds 20 rupees and the normal price per km for a rickshaw is 7 rupees. Sounds not a lot, but a rickshaw is your daily transport vehicle in Bangalore unless you get a 2-wheeler. This I would recommend to you, so do not forget your international driving licence. I currently try to bypass the Indian bureaucracy to get an Indian licence, but it will be much easier to possess an international licence.

In addition, if you go to an internship it is clearly recommended to get an employement visa. I actually know it before apllying for the visa, but the embassy guys told me to get a business visa. As far as I know, it makes no difference (till now).

TortoiseSVN of Hell

Just researched about 2 days to find out why a cannot connect to my repository via ssh and private key file.
Only the following few steps were necessary to solve me issue:

• Reviewed nearly everything
• 3 times generate new private/public key pairs
• 2 times reinstalled Tortoise
• remove all stuff from registry which contains anything about Tortoise
• demotivated bang your head against a wall
• bored reading of the tortoise help

suprise: the rescue paragraph:
If you use this last method, be sure you do not have a default username set in PuTTY. We have had reports of a bug in PuTTY causing connections to close in this case. To remove the default user, simply clear HKEY_CURRENT_USER\Software\SimonTatham\Putty\Sessions\Default%20Settings\HostName


Good damned, yeah guys this was exactly my problem. Thanks for the good documentation. But please, ensure to get better error messages as "Connection closed unexpectly"



LG phone just arrived

Yeah, my LG new chocolate just gets delivered. Awesome, only two times I had to send it back. First, the phone randomly powered off without any reason. I wore it in my trousers and right after a short walk it was off. Weird, next time I got it the glass of the camera was obvious broken. At the end I wait more than two month for my new telephone. But now it is here, and it is really cool. It has on its touchscreen a complete keyboard. It is perfect for writing blog post.
Additionally, there is a nice picture flow for your favourites, I just need for every contact a picture. The next cool function is the video playback, it is like a mobile cinema 800"325.

Matching HTML Tags with regular expression or why blogroll identification is not so easy

Yeah I just got it!
So trivial the problem even sounds, for me it was a hard lesson to learn.
Szenario:
Just walkng on the crawler and try to identify blogrolls, so far sounds easy. Yeah, if one will ever be so nice to put this information in a well-formed RSS2.0 feed.
But as far as I see each blog can easily insert a blogroll in his html content with nearly no standard. I have to admit that there several WordPress Plugins and other concept, which serve the user as creation helper.
Thus this generator just can be identified by tag-ids or css-classes like 'xoxo-blogroll' which can be easily changed, it is a hard way to extract this stuff in a general way.
So I end up on implementing an algorithm which extracts the inner html of an tag which contains 'blogroll' (so css class, ids and even title get recognized).
My first idea, yeah, just another nice example how unreadable regular expressions can speed up your code and copyright it simultanously.
Here my drafts:
]*?blogroll[^>]*?>(.*?) Here we go first draft for a div tag <(.+?)[^>]*?blogroll[^>]*?>(.*?) next step matching a random tag wich contains  blogroll anywhere
Note: I reuse a group directly in a regular expression, nice feature, especially for this use case.

But as you may notice, we have to consider multiple open and end tags of the same kind. So I just think about this problem some time and I just remembered to my theoretical informatic studies, where my prof taught about push-down automats and the type-3 grammatics... So at the end, it is prooved that one cannot check my use case with a regular expression, so I have to insert 2 count variable to check the right number of open and closing tags to get the whole content.

<([A-Za-z][A-Za-z0-9]*+)[^>]*blogroll[^>]*>

recognize the beginning tag and than just match to the beginning tag and count open and closed tags till there are more or equal closed than open.

Amazing Toolchain DXF

The scenario: Given we have a simple Logo, just a circle, as a dxf-File so called Drawing Interchange Format. So what is actually nessesary to fill the circle with dark blue and get is as png, svg, pdf.
Normally, one think the solution is simple just give me Visio and I import this stuff as CAD-Drawing use the fill-button and click export to the severall format. BUT it is definetly not so easy.
Although Visio supports fill out, it did actual not work at all. So I tried first to export it to a high resolution jpeg and tried to fill it out in Paint but he we got the problem of antialiasing stuff. So the edges blur out, this does look dirty and uncool. Next I exported out of visio a svg file, open it in firefox, manually set the fill style for the svg path and try to reimport it to powerpoint (tool of my choice for presentation). But as we all know Microsoft does not like SVG at all (although they are active member in the community, I still hope for svg support in IE), Powerpoint was not able to import the svg. A friend of mine imported the svg in KeyNode and export it as ppt. Now I was successful on opening the ppt with powerpoint and now I could export all my wished format from Powerpoint.
Additional I have to mention that a tried to search some free tools to edit dxf files directly, the only stuff I found is an pure french Java editor, which is in no way useable at all.

What a amatzing toolchain just to handle an dxf-file. If you got advise for me please comment.

Extreme BP Work Today

Just end up on working with Eclipse EMF and Eclipse JFace wizards. What a pain!!

Especially the construction of an Eclipse wizards is more difficult than I estimated. It just catches exceptions without any feedback, just from time to time a “Event Loopback” occurs which is easy to track. Additionally all the magic SWT style number are weird. So, you can just instantiate a new Composite with

new Composite(parent, SWT.V_Scroll);

and get a Composite with a vertival scrollbar. Sounds cool, isn’t it. But if you try to add several other composites as children of the scrollable, there is no scrolling at all. I just try to get it working.
In addition, there is no possibility to remove pages from a wizard, I temporally just monkey patch it, but I asked myself, if one should really only use constant pages, and just modify the contained composites. Another issue was the complete unchangeable order of pages, so I just added a public arraylist and redirect all accesses to the private pages of the supertype.
According EMF, it really do not fit in my mind, why one cannot inherit from data types. Especially EMF specific interfaces, which I think should be supported or at least been modeled in the Ecore model itself , are not available to inherit from.
Some nice idea for EMF would be an code synchronization plugin, which will kust update the models, if one change the parameter type of a method or just add a new attribute. Because the development process suffers from the frequent switch between code and model, just for keeping the model up to date.

Today, I just get an insight into the upcoming UML stencilset for the Oryx Editor (Oryx Project). It look great, nearly all concepts of UML get supported, but it was an hard manual matching against the UML meta model. Let’s think about a way to parse xmi meta models to stencilsets and vice versa, would be a powerful concept. I will just go on research on this topic.

Call a JavaScript Function with all given arguments

Sounds easy, but it is a bit tricky. Once one have to now that this:
  function test(){
   do();
   test();
}
ends in a recursion, because the function pointer  test, only will be resolved to the value at runtime.
I ends with this:

var tmp = fn;
fn = function(){
if(!!pageTracker){
pageTracker._trackEvent("category","value")
}
return tmp.apply(this, arguments);

}
With this snippet you can add a Google Tracking Event, just by wrap it in another js-function.

Nice Idea for an wave gadget

Currently after creating a wave and inviting somebody one cannot kick users out of a wave.
So the idea was to build a gadget/robot which handle a body list of wave users. The wave will get encrypted with every change the key will change.
After kicking an user out of the wave, the key of the user will not be updated, so he will not longer be able to participate at the wave.
Practically it may be possible to insert new unencrypted content to the wave, but the encryption mechanism will automatically hide unauthorized messages.

SWT Project Sprint Planning Session 3

Amazing, what people implement for a lecture at the Hasso Plattner Institute. Some guys really work 200% more than anybody ask for, but as contrast some feature are really just functional. Nobody seem to test the UI. So it looks like an incoherent clutch of input fields in combination with some weird checkboxes.
Guys, please use your stuff before presenting it, user will be grateful.

Working on Web Crawler

Since a couple of weeks a friend of mine and I working on a blog crawler to saving the blogosphere. Since now we saved about 50000 blogs and worked around 3 Mio web pages. Sounds much, but it is not. We challenging a lot of other crawlers around including google. Overall crawlers usually get about 300 site per second. As contrast our crawler just get 2500 site per day. That really weird.
Concerning the fact that we distributed our crawler to gain more cumputation power, but here is the problem. To guaranty that all blogs stay linked in the database and to avoid duplicates in the db we need to define a central databank , which seem to be the bottleneg.
Every crawler client just waiting severall minute for the database just to answer a very simpel select statement.
So well my database knowledge is very limited to some base stuff teached at the university. Currently I try to speed up the query using  CREATE INDEX.
After all last time I heard about asychronous distributed message queues. This seems to be a good option to get the whole job handling out the database. But I think that only the INSERTs consume so much time.

So to sum up, buying new hardware is a good option.

Start Blogging

Hello World,
that my first blog, let's test it. My intention for creating this blog is primary to practise web2.0 and share my knowledge. So I hope to offer some useful informations for everyone here