dirkmeister.de

CDU party heads call for state-Coursera

2018-11-06T09:12:00.001-08:00

The policy proposal described here by the German IT site golem.de is at the same time surprising and at the same time really not: The heads of the CDU, the biggest party in Germany, calls for a state-Coursera.

The platform is to be government run and each course has to be government certified. Apparently, they want to use 10% of the nations education budget for it. 3 billion per year. The proposal states that the existing on-the-job education offerings, e.g. for learning a new software framework, were too convoluted and not all certified by a government agency. "Convoluted" is German for "organized by competition". The term is always used when there are more than three competitors in a market. Oh, it is so convoluted, they start to shout. So, this has to change because "Germany".

As always, 5-10 years too late? This clearly already exists and wasn't too successful after an initial hype. At least, I would call it bold to promise 10% of the education budget towards this.

Catchup 2012-2014

2014-07-13T08:19:00.000-07:00

Two years since the last blog post. The last entry was „Farewell Bay Area“ written when I left the Bay Area after the internship.

Let’s catchup:

When I arrived at the airport on August 1st 2012, the first call was to colleague to ask about the state of the dedupv1 project, just to hear that it was killed for all intents and purposes during the three months of the internship. Very sad, but not having to write code that "actually works" gave me time and freedom to experiment. The other insight was to use trace-driven simulations instead of the real system for early prototyping of research ideas. The result was a nice paper chain: November 2012 (Supercomputing, Salt Lake City, Utah), February 2013 (FAST, San Jose, CA, to my knowledge the first European PhD student ever presenting at FAST), July 2013 (SYSTOR, Haifa, Israel) and two more not so important/good papers. Having the final paper at SYSTOR in Haifa was awesome because I could end my academic publication career at the venue where I started it in 2009 and the BLC approach presented there has been IMHO my best work (yet ;-)). Graduation in May 2013.

I joined Greenplum where I did my internship. It had now joined forced with other parts of EMC and VMware in a company called Pivotal in June 2013. Let’s make a long story short: I love the product (GPDB). It has great potential. MPPs in general (Massive Parallel Databases) are increasingly the way to go for Big Data analytics. The potential of the 1990’s research is now finally materializing. Also, lots of new innovation happening in the field. However, Pivotal was not my place anymore. Greenplum will always be important to me because they were the first where that have me a chance. I left in October after finishing the project to join Pure Storage in November 2013. Back in (block) storage and Pure is awesome.

I have been working from the London sales office since November. I like England. On good days, it feels like a cultural mixture of the US and Europe that I like. It is mixing „individualism with universal healthcare„ as a friend on mine worded it. Politically/philosophically I have always been more influenced by British authors (Locke, Smith, Mill, Popper, Keynes,....) than continentals/Germans (Hegel, Marx, Adorno, Heidegger, ....).

As I evidently researched and published a lot data deduplication and this kind of technologies are important for Pure and (some more reasons and some persistence), we have been able to petition of a visa. In three weeks I am going to say „Hello again, Bay Area“. Let’s start a new chapter....

Farewell Bay Area

2012-07-29T18:44:00.001-07:00

The most important things this weekend are packing and having farewells with everybody.
The internship is over.

In the end, it was a great time. Maybe one of the most interesting summers I ever had, certainly the one with the best weather.

Working for a database company worked out surprisingly well, given that I have no formal database background. My theory for this is that all software-intensive storage systems, where I would include data deduplication systems, distributed storage systems, and database storage layers, are driven by the media (usually hard disks, Flash storage). Whatever the user interface is, the way you design algorithms, how you try to make your IO pattern optimal, the basic building blocks for concurrency and fault tolerance are all the same. The basic skills (coding, data structures, design) of an engineer are the same. Therefore it doesn't really matter if the upper levels are SCSI or SQL. We are driven by the media.

It was great that my work was really appreciated. I worked on the design and the prototype of a novel storage layer and on test infrastructure as a side project. Both are topics I really like.

The last week was really helpful because multiple people including professional recruiters looked over my resume and gave line-edits. While my resume followed the U.S. style, it contains many formulations let recruiters trip. For example, I wrote "With Honors" as English transaction of "Mit Auszeichnung" (the highest grade we have), but "with honers" is the U.S. equivalent to "good" or even less. The resume is now in a much better shape. Otherwise the last week mainly consists of finishing the last pieces, handing over everything and painting the project name on a wall. Those who know me well, know that finding the name for the project was probably the most difficult task here.

The Bay Area is an awesome place. So many smart tech people. Literately everybody I spoke with about this had this favorite story about meeting somebody awesome and/or famous at a random place like a small book store. At work, there have been so many people with from these schools or these top companies or just tons of experience. Similar minded people who have to same attitude to coding/design or read the same professional books. It was interesting, I learned a lot, and I would like to work with these people or similar minded people again.

Also, there are so many interesting companies: The big ones, the middle ones, and the small ones. The change is high that if you have heard from a company or if you like like an app, it comes from within 30 miles from here. In the U.S. there is also the Seattle area and the Boston/Cambridge area, but still, here is it.

Have I mentioned the weather? Probably yes. Have I mentioned the great landscape here? Have I mentioned that in certain months you can go surfing in the Ocean and snowboarding at the same day?

I am so grateful that I had the opportunity to do the internship. To do one was probably one of the best profession decisions I made. I can only recommend it. Well, I recommend it if you are similar to me. For a suit job like consulting or non-tech management, it is not worthwhile. Search a company you like, that does something interesting, something challenging and go for it.

The living situation has been strange, much stranger then what I could imagine. So strange that it is not an appropriate topic for a blog post. However, the room mates have been great. Totally diverse people from (in alphabetic order) a sociologist that programs C to do this simulations, over startup kids, a philosopher, a former CS guy who switched to law, a bio medical researcher whose love to ice cream is only surpassed by Camaros and Froyo, to a rowing, hyper-competitive law student. And more law students and even more people. But the group worked pretty well. We have done something interesting (like class-4 white water rafting last weekend) nearly ever weekend. I certainly would have left the house without these people. Some of them will eventually end up back in the Bay Area. Hopefully, we keep the contact.

Tomorrow I move to an airport hotel and on Tuesday at 6am my plane leaves to Frankfurt. Then: Back to normal.

I think I have a few nice photos left, but the camera is already stored away.

Books I have read during the internship:

The Design of Design, Fred Brooks
The Algorithm Design Manual, Skiena (I finally bought my own copy from my internship salary. It is necessary since I no longer have access to the decent University of Paderborn library)

The Ph.D. Grind, Philip Guo (pdf)
An Introduction to Mathematical Cryptography, Hoffstein
Quite, Susan Cain
John Adams, David Mccullough
Undaunted Courage, Ambrose

2 weeks to go

2012-07-16T22:43:00.002-07:00

3 month are pretty long. It is not so much work or the U.S., it is life in a dorm style environment is wearing me out a bit. Saturday, I took a day off. Nice solitude in the garden.

On Sunday, I was finally in San Francisco. Doing touristy things like Ferry Building, Pier 39, Fisherman's Wharf, Dim Sum in Chinatown. In the following a few nice photos:

The focus of the last week was networking or at last a try to do networking. I was at a BASE meeting on Monday. BASE stands for Bay Area Scala Enthusiasts where Scala is a nice programming language. I used it for example for to write tool which helped me to acquire the data for my Supercomputing 2012 paper. It were two nice talks, but no good networking. Some people I talked to were strange guys "between jobs" (aka unemployed) that go to tons of meetups in the Bay Area to get free pizza and beer.
Tuesday: Beers with colleagues at a fish restaurant near work.
Wednesday: Wine tasting at Google's Mountain View office. That was really nice. Our Google law intern invited me. Thanks.
On Friday, I had a important presentation about the work I done during the last weeks. It went pretty nice. Afterwards I had good talks with different engineers. I meet a whole bunch of good, really skilled engineers. It is fun working with them. Free beer afterwards.

The weekend before that we were rafting a south fork of the American River. The river itself had much less rapids then the cache canyon a few weeks earlier, but better ones. A big advantage of this setting: The company, we rafted with, was so professional. The meeting place was clean and in good shape, the the guiding was per-boad, the self-prepared food for lunch: Good. What impressed most was the reaction when some fall into the water during a rapid. All the guides coordinated their boots within seconds so that was easy to pick the person up afterwards. We were pretty impressed so that we will do it again. This will be so much fun.

Why do we do so much? For two reasons: 1) there is so much fun stuff to do here in the area. 2) My internship salary is so much higher then my German university salary and I cannot buy e.g. fun gadgets without getting trouble with the German border robbery. So I spend a low percentage of the bi-weekly salary I buy fun experiences.

Another week in the Bay Area

2012-07-06T21:37:00.001-07:00

The more time I spend here to more likely it is that I will return after finishing my PhD. If you are in tech, this is the place to be. Where else do you meet e.g. a (former) hiring manager of a few nice storage companies in the line of a bookshop? Work is interesting and there are quite a lot of smart and engaged people to work with.

Doing the internship was a really good decision. Sure, I should have done this during the Masters time, but even at this late stage it is worth the time. I don't want to miss it.

But even how much I like the internship and the area, I miss a good couch, my car, the nice programming sundays while watching a TV series. Actually, it is easy to keep the contact with home, with friends and family. T-Mobile has a 10 USD for its prepaid mobile plan that allows calls to German phones with no extra costs. Skype and Mails help, too. The T-Mobile area coverage is hell (ok, this sentence is easy for sentiment analysis), but the add-on is really worth its money.

I will fly out on 7/31 and arrive in Frankfurt the next day. Thanks to the bureaucracy of JGU, I have two weeks of holiday.

Ok, after these random thoughts, a few pictures and stories.

Last weekend was strenuous. I and a friend from the house went to Yosemite. For those, who are not that familiar with the U.S. Yosemite is a famous national park. After Yellowstone and the Grand Canyon, I would say the third most known. And probably one of the most accessible. The park is around 4h east of the Bay Area. Five hours or more if you are stuck on 101 during the Friday evening rush hour.

We went up to the top of the Yosemite water fall, North Americas highest waterfall. The so called "Upper Yosemite Falls Trail". If a site declares it was very hard, believe it. The trail was not long (less then 4mi), but the elevation gain was nearly a full kilometer. You can see good on these pictures.

You start at the base level and you end up at the top of these falls.

You ping pong between the two rocks and crawl up the rocks on pretty rocky trails.

Actually, I found going down more difficult then up. Because you always look down and think about slipping and falling. "Height" is not really my thing.

It was the weekend before independence day and therefore there was quite a traffic on the trail. I would guess around 500 people on that day. At some point, you start asking the hiker going down how much is left until you reach the top and they help with friendly words. Later, when you go down you also help with encouraging words.

Afterwards, we went to the Hotel. Bad surprise: "We don't have a reservation on your name". Not the sentence you want to hear after such a hike. Nice surprise: It later turned out that the Hotel was overbooked and they upgraded us to the Ahwahnee, a really good Hotel in Yosemite Valley. It is hard to describe how good the hotel is. Find it out yourself. The problem: If you don't have luck as we had, you are at above 500 USD per night. It is probably the best hotel I stayed in up to now. Before the Hyatt Lake Tahoe (MSST 2010) and Bayerpost in Munich.

The independence day was also really nice. It started with "Dim Sum", a special chinese kind of food. The restaurant was in Cupertino. But it felt actually like China, a nicer China. In the complete "mall", the direction sings have not been translated to English. This was for lunch. In the evening, we had a BBQ. And then we went to the near Shoreline Amphitheater in Mountain View for a concert of the San Francisco Symphony Orchestra. Of course, with fireworks.

It was really nice. The only issue: Parking. It took us two hours to get of the parking space. Thanks Mark for forgetting your badge for free parking.

There is so much left to do. I was only two times in Santa Cruz and I was not yet surfing. I really want to go surfing. And I was only a few times in San Francisco. However, weekend are running out very fast. This weekend, another rafting trip is scheduled. This times with the house group. We thought about going to the river where I have a few weeks ago. But we decided to go to another river where there is a guided tour. That will be fun.

Internship Midterm Review

2012-06-24T15:34:00.000-07:00

I have reached the middle of the internship. 5 weeks to go.

I have noticed that the last blog post had much less reader then the posts before. As an advertisement, this new post contains a ton of new photos. Tons of new photos. However, Facebook users or Google+ users could already see the pictures of quite some time.

The major issue of the last weeks is the unfortunate situation in the house. Long story. Too long and not appropriate for a blog. At the moment it is ok. Lets hope it stays this way.

We have a lot of new people in the house. Actually, only a single house mate is the same as when I arrived. When I arrived, most people were German. Now all Germans are gone and have been "replaced" mostly by law associates. U.S. law students are not that different from lawyers in Germany (as I know them from politic times), but even more competitive. A bit like "Boston Legal" characters made reality. Two two-years are working for large law firms in the Bay Area, one first-year is with this company that also have a office in Munich, when you understand what I mean.

I still do much sports. At the moment, we as a group hike nearly every Saturday in national or state parks, monuments or shorelines. We have been in Sequoia National Monument (Warning: Link contains Comic Sans). The hiking path was great. Big Basis state park with really nice waterfalls and at the Point Reyes National Seashore. The hiking distance increased from 8mi in the two weeks ago to 13mi yesterday. Always with a significant hills. Really exhausting, but the sights make up for it. Last weekend I was rafting with a college from work, who also studied at UPB and friends of him. Except that the other car of the group was part of an accident, in which thankfully nobody seems to be hurt seriously, it was a great weekend.

Here is a link to my picasse albums:

Here is a best photos of the hikes:

One of the best properties of the Bay Area is that you have all this great landscape around here. Forests/Redwoods all over the place. One hour and you are in a beach. A few hours to mountains for skiing, a few hours to more desert-like places, one hour to "The City".

The Palo Alto Baylands are still my favorite running place. I try to run there two times a week around 1h to 1.5h.

On a Sunday a few weeks ago, I finally have seen a U.S. sports event. College baseball. The final game of the season with Stanford Cardinals against Cal Bears. Photos available, together with a photo tour over the Stanford Campus.

The first half of the internship is over. This was fast. I feel like a part of the team. I am not a lesser part because of my intern status. This is good.

This week, I got knowledge that one of my co-workers is only working for the company part time and is a full-time tenured professor at a smaller east-coast university. I actually have read some papers from her.

It is a really interesting experience so far. The company seems to see itself -- much more then EMC in general -- as a Silicon Valley based company and I found that really nice. I finally got my company gear (Laptop bag, T-shirt, ...). My observation is the most acknowledged proof of success in the Bay Area is not a Rolex clock or a Armani suit, but the company T-shirt.

The internship is a large test to see if I would like to work in the Bay Area after finishing school. While my overall opinion fluctuates a bit, my mood is good. It is not unlikely that I will return. However, I will not do a final decision before returning to Germany.

What are the plans for the next weekends? Next weekend, I will probably do a small trip to Yosemite National Park. It is a must-see and will be a great hike. In the week afterwards, I have a day off. It is the 4th of July. I will go to the Amphitheater in Mountain View, actually not more then 15 Minutes away by bike, to see the San Francisco Symphony orchestra playing to fireworks.

Third week

2012-05-20T21:09:00.000-07:00

Ok, this post was started as the post for the second week. But then the time ran out and it was again the next weekend. So it is the week three post.

3 people from the shared apartment left this week. While that is definitely bad, it has its pros: The house is not over-full anymore. New people will arrive eventually, but still no CS people. Strange, I expected to meet some more here. On the other hand the mixture in the house is nice: Sociology, Eduction Science, Physics, Philosophy, and Biology. Update: The new people actually arrived. Two law students.

Here is a picture of the (old) group:

(Used with permission of L.B.).

The last week was filled with work, and BBQ. One BBQ as a farewell party, once because good friends from Germany visited me.

At work: After the relative boredom of the first week, I am now doing something: Designing and prototyping. Deep in my conform zone. It is pretty much like grad school. I think I have a nice system design for the problem. But in the next weeks, let's hope that we can get me out of my comfort zone a bit. I am not in the US to stay in my comfort zone.

On the second weekend, we were in a club in Palo Alto (nice, but it closed as early as two) on Friday. On Saturday, we were in the Mission in "The City". I still don't feel that this part of SF will ever be something were I well comfortable. Too dark, too dirty. The StreetView link is actually the nicest and cleanest place because it is directly at the BART station. On Sunday, I needed a day off, a day of solitude. To took my car and drove a large round. To Half Moon Bay, over Highway 1 (also called Pacific Costal Highway) to Santa Cruz, and then back to Palo Alto. It was really a nice trip.

Here is a picture of a nice place between Half Moon Bay and Santa Cruz:

This weekend was also really nice. Did I mention the always nice, but not to warm weather with 20-25 degrees?

I have seen the Champions League finals at an fraternity house on the Campus. Free beer and free pizza. :-)

Today started with a challenge: Biking from Palo Alto to the Computer History Museum in Mountain View without seeing a Google office building. Please, see this map to visualize how big that challenge was. I failed that challenge. Probably it is not even possible, but furthermore I got lost and drove to the next white building because the museum is also in a white building, but that was no the museum…. In the end it is a 5-mile bicycle ride, directly following the bay shore line.

The museum, which I reached eventually, was really, really nice. It pays off that nearly every company within 30 miles contributed a lot in money and exhibition stuff from their basements. For example, the storage system room, which e.g. presents a IBM RAMDAC, was partly sponsored by XIVs Moshue Yanai. The fully functionally Baddage machine was also nice. It doesn't seem to be larger then the Nixdorf Museum in Paderborn, but certainly has the more interesting artifacts.

After being back, we drove (and then hiked) to "The Dish" to see the partial solar eclipse that should happen today. The dish is a 150 feet radio telescope, located in the hills behind the campus. However, we haven't seen the solar eclipse. But the area is really, really nice. It is actually a very popular running site.

Here are more pictures of today:

Palo Alto

There are other nice, mixed (non published) pictures:

PaloAltoMixedPictures

Next weekend is fully planned. We go hiking on Saturday and see the baseball game Stanford Cardinals vs. UC Berkeley on Sunday. I don't unterstand baseball. Well, that is not totally right. I understand that is mainly about beer and hotdogs.

First weekend after starting the internship

2012-05-06T13:48:00.001-07:00

I am now three weeks in the US, two weeks in the shared house, and one week in the internship.

To destroy all preconceptions of the U.S.: It is extremely easy to get tons of good food here: Great salads, fruits, meat, everything. I like Trader Joe's much more than Safeway. The Aldi brothers should bring Trader Joe's to Germany. Food in general is expensive, but e.g. salads aren't really much more expensive as in Germany.

I do a lot of sports. Biking to and from work, running in the Baylands, swimming. Today we wanted to go biking/hiking in the hills beyond the campus, but -- to be honest -- I am currently not fit enough for that. I will try again in a month. And: Everyone also seem to do sports too. I have seen dozens of cyclists today. You see people running all the time.

Third preconception to destroy: Crime. Crime doesn't seem to be a problem in Palo Alto. You see that e.g. on the fact that a lot of parked bikes have bike helmets hanging on them, but the helmets are not locked or so. In the swimming pool in the Rinconada Park is no way to lock your belongings. Also at night, e.g. on the way back from a pub, Palo Alto doesn't feel unsafe. It may be different in South Palo Alto, but I have never been there and I also don't really know where it is. It is probably somewhere in the South, but I am a bit south, too. Mountain View is not that far away by bike. I checked because I will go to the Computer History Museum eventually. I have to see which is bigger and better. The Computer History Museum in Mountain View or the Nixdorf Computer History Museum in Paderborn.

Back to crime: San Francisco feels totally different. I was there on Tuesday and on the bus back to the train station, there was an issue in an Fast Food restaurant near Market Street with four police cars and medical emergency vans.

A lot of people say that Palo Alto is boring and San Francisco, normally only called "The City" here is the place to life. But I think I prefer Palo Alto. On the other hand, the crime map doesn't really look empty.

The shared house has no TV. I feel to miss out on an important part of American Culture. I look more U.S. movies and TV shows at home than here.

To the internship: A few thoughts.

The internship is a large, practical "experiment/test" on multiple issues: Do I want to get a job in Silicon Valley? Can I imagine living here for years? Do I want to work for that concrete company afterwards? Do I want to be go into "real" engineering (currently the most probable answer, but we will see. Nothing is decided yet), a company research department which a lot of storage companies have, or stay in Academia?

I failed to do an internship earlier. I should have done that 5-6 years ago. The time at arvato systems was good and very helpful, the paycheck was nice, but in retrospect I left a year too late. The stuff I worked there on is to different that it is not helping me now from a resume point of view. So maybe some companies fail to see a proof that I actually can develop stuff. I think I can develop interesting stuff. I think I proofed that before, but not in a visible, normal way. But the internship should help proofing that. I mean some companies where I applied for the internship didn't even bothered to answer, not even a negative response. This should not happen when I search a job after the PhD. Well, probably I will not apply at these companies anyway.

I found it always stupid in Germany that you have to send (sometimes, e.g. at the Uni Mainz also officially signed) copies of all certificates directly at the beginning of a job application. IMHO, it shows a huge mistrust on the applicant. This is not the case at all U.S. based companies where I applied up to now. Which are basically one company twice and half a dozen or so for the internship. The big BUT here: the company hired a kind of private detective company to check my education background. This seems to be the normal procedure. This feels like a higher mistrust than the German way. If the alternative is external background scanning, I prefer the German way. Is this usual in U.S. tech companies? Why are these things done for an internship position, but not for CEOs? How to these screening companies find out anything? I think that the University of Paderborn would not be allowed to answer any information requests by such a company under German privacy laws.

The first days I read tons of design documents on the database. It took a few days to get the laptop and a few more days to get access to the Wiki, source code repository, and all the other good stuff that belong to a good development process. Now it can start.

I meet another Uni Paderborn alumni at the company. He is working on machine learning on top of the database. I think, it is really nice to see people from the same university a few thousands miles westwards, working in the same "small" company.

The internship was a big bet on the fact that developing on the database access/storage layer is not really that different from other software-intensive storage or file systems. That seems to the true.

I have read on the Internet that at the company, there is something free to eat "three times". I thought that it is nice that you can also have breakfast there. What was meant was, three times a week, not three times a day. There is no staff restaurant. But there is a sandwich store in the office building. I was a bit surprised at first, but the company has grown so much in the last year and a staff restaurant, with real lunch, is really not on the priority list right now. On the other hand, a software development company in Munich that I "visited" last year has a free staff restaurant for only 50 staff members at that office. But you cannot really compare that.

My boss worked on deduplication before: In a discussion about a specific data structure, she said that they used it a lot at the other department for their deduplication. Yes, I know. I have read the paper dozen of times.

Dutch Queens Day

2012-04-28T22:16:00.000-07:00

The Dutch Queens Day event in San Francisco's Golden Gate Park was fun. I was surprised how large the Dutch community is here.

We (mostly from the shared house) have gone there by Caltrain to the AT&T stadium and then by bike, through the complete city, to the park.

The Golden Gate Park is so huge. 1km x 5km or so. so many runners, cyclists, groups, and families. After around 25km including SF hills, I will call this a day.

Frist week in Palto Alto

2012-04-27T13:44:00.001-07:00

The first week in Palo Alto is nearly over.

It is difficult. I haven't up my mind about this city up to now.

So here are a few random thoughts about it:

The streets, all streets, are very wide. This was expected, but a nice surprise are all the bike lanes (StreetView). It is ok to get around by bike in the city. I use the bike directions service of Google Maps to come around. The service is in beta, but I think it is probably well-vetted in the area around Palo Alto.
The houses are nearly always, single or at max two-story houses and a lot of bungalow buildings. Mainly wood buildings. My room is in such a single-story bungalow. I haven't seen any multi-family houses like they are so common in Germany.
Palo Alto is rich and broken. It is strange. The houses and cars are here so huge and big, and S-class Mercedes looks like a small car. On the other hand, there are regular power blackouts. For days. It is in general more dirty than at home. There are so many small things were I think "Ohh, I know this from the 80's" like bank checks and trains only with manual sign about the train number and train direction. I also now really get what they meant with buffer bloat. I never noticed it in Germany, here, the ping times often, too often, go up into the seconds range.
Food is ridiculous expensive. I understand now why the people in the TV series always order food. I feel that everything at Safeway doubles the REWE/Real prices. I like the Trader Joe market near the Campus. I don't know if it is cheaper than Safeway, but much nicer interior. Fun fact: Trader Joes is partially owned by the Aldi brothers.
With regards to "as seen on TV": I know this country mainly through TV/Movie coverage. So I so many situations are I think like "X is like it is shown in movie Y". E.g. the caltrain uses the strange two-story trains like in "Source Code".
I was not out of dinner, but there are so many, nice looking restaurants in the City, e.g. at University Avenue: Burger, steak, far-east, middle-east. And of course -- we are talking about California -- a lot of vegan and organic stuff.
The temperature differences within a few miles are huge. On sunday we went to Santa Cruz because it were 24 degrees (Celsius), but Santa Cruz only a few miles away over the coastal mountains it were 14 degrees, cloudy, and windy. After a short stop, we drove back. The weather was not good, but the beach 1/4 filled anyway and the highways to/from Santa Cruz were jammed. I simply don't want to know how full it is there on sunny summer days. One of my goals for the time here is still surfing. So I will have to find it out when it is a bit warmer like end of May or so.
On Tuesday I was there a second time. The weather was much better. I really like the beach area and downtown. Santa Cruz is a nice mixture of a beach town, old mexican/spanish influence, and a collage town. I was back in the Santa Cruz bookstore. Got a biography about John Adams and a book about the Lewis/Clark journey. Besides, this one little bookshop in London, it is my favorite book shop. Lots of old books, small notes with comments about the books by customers and staff of the store. Nerdy stuff, history stuff, reading sessions, ….
Everything in the city is about the University. Sooo many people with Stanford shirts, bags, and pants. It is not possible that all these people study or work there or have studied there. There are so many. I am -- of course -- wear my UPB shirt with pride. Well, and also my Slug shirt, even if that is cheating.
My English (pronunciation) is probably not getting better. The shared house is shared with mainly people from Germany and the Netherlands (all Stanford visiting scholars).

My current impression is: I think it is ok to live here, but it is not so impressive that I have to convince my whole family and friends that there can nothing better then living here. Actually, from the living situation and quality of living situation I like Germany more. It is all about the jobs that are here and not there.

On the other hand, I know that I really need time to adjust to a new city.

The news of the week for me is that the University of Mainz allows me only to start when I sign the employment documents in person in Mainz. This is so great. They knew before that I am not there, that I am in the internship. So great. In the worst case, I start late, and loss time for the PhD and a ton of money. I love Mainz.

On Tuesday, will be the first day in the internship. I was there for a first visit on Wednesday. The offices look really nice, but everything is a bit smaller then expected. The office room of the team is a large cubicle room -- as expected -- but extremely quite. There is a shuttle service from and to the Caltrain station, but I am not yet sure how good it works out. On Wednesday, the shuttle bus arrived 1/2h before the next train left into my direction.

Shared Appartment

2012-04-23T09:07:00.000-07:00

Two days ago, I arrived in the shared apartment. My home for the next three months.

Here it is:

Größere Kartenansicht
The first thing I bought was a T-Mobile sim card for my phone. Running around in a large city without GPS is no longer an option.

Palo Alto is a big (50.000 residents), flat city with enormous houses, enormous cars, and (surprise) bike lanes. Sometimes it feels like that the complete city is circled around its university, the Stanford university. Most of the people I share the apartment with are visiting students there. So many, many people wears Cardinals shirts and even the Trader Joes is full with paintings with large Stanford-S symbols.
I, of course, wear my University of Paderborn shirts, but I only have one of it.

However, I would like to view a Cardinals game. It seems to be the baseball season. Maybe a could get cards for a game there.

Now I search the nearest Starbucks. I have to finish a paper and there is no coffee maker in the apartment.

MSST 2012 is over

2012-04-21T14:03:00.000-07:00

The MSST 2012 is over. Next, I have a week free. Free meaning I have a paper to finish before the internship starts.

I just arrived in the shared house in Palo Alto where I have my room for the next 3 month. Perfect, 24 degrees (Celsius).

Here are first photos from the conference groups.

Finally! Arrived in Pacific Grove after 13 delay

2012-04-16T15:27:00.001-07:00

Finally, I arrived in Pacific Grove.

My flight from Frankfurt to Chicago was 90 minutes later. No chance to get the connecting flight to San Francisco. However, I really wanted to attend the MSST tutorials today. But the last flight that night was totally overbooked and I didn't got on that. Night at an Hilton Airport Hotel and first flight today to SFO.

In the end, I arrived 13h late. Bad start.
However, the conference ground is great. Small wood-like houses between trees. It swells totally after resin ("Harz").

Reactivation of dirkmeister.de

2012-03-24T03:53:00.000-07:00

Next month, an interesting time begins.

After presenting some recent work at MSST 2012, I will do a three month internship at Greenplum, the data analysis part of EMC, in San Mateo: Three months California, three month Silicon Valley, three month sun, three month coding.

Some of my friends requested photos, updates, and proof of life. I could also use Facebook, Google+, or even twitter, but believe it or not, not all my friends use Facebook or Google+. Blogging feels very much like 2004, but it is ok for such a trip. For this reason, I will reactive this blog.

I don't know the blogging policy of Greenplum/EMC, so I will stick with being on the safe site by doing two things:

Stressing that all views don't represent my current, previous or future employers or project partners, including EMC, the University of Paderborn, and the University of Mainz.
Not even acknowledging that there could be something like a Greenplum Database.

Therefore, no technical content here. All the internship posts will be about photos, life in Silicon Valley (from my point of view), and weekend trips.

This will be fun.

Storage Systems Course: My proposal

2010-01-09T05:43:00.000-08:00

In my last post, I summarized some of the storage systems courses from international top universities with storage system labs.

In this post, I will distill my own ideas and my own views into a structure for a storage system course. Here, I assume here a 15-weeks course with a single 1 1/2 hour lecture per week (as we have in Germany):

Introduction, Overview, Disk Drive Architecture
Material: Ruemmler, Wilkes An introduction to disk drive modeling
Disk Scheduling / SSD
Material: Iyer, Druschel. Anticipatory scheduling: A disk scheduling framework to overcome deceptive idleness in synchronous I/O, Agrawal et al. Design Tradeoffs for SSD Performance
RAID
Material: Patterson et al. Introduction to Redundant Arrays of Inexpensive Disk (RAID), Corbett. Row-Diagonal Parity for Double Disk Failure Correction
Local File Systems
Local File System Case Studies: ext3, btrfs
Material: Valerie Aurora. A short history of btrfs, Card et al. Design and Implementation of the Second Extended Filesystem
Local File Structures (Sequential, Hashing, B-Tree)
Material: Comer. The Ubiquitous B-Tree
SAN / NAS / Object-based Storage
Material: Sacks. Demystifying DAS, SAN, NAS, NAS Gateways, Fibre Channel, and iSCSI
Examples: NFS, Ceph, GoogleFS/Hadoop DFS
Material: Weil. Ceph, A scalable, high-performance distributed file system, Ghemawat et al. The Google File System
Snapshots and Log-based Storage Designs
Material: Brinkmann, Effert. Snapshots and Continuous Data Replication in Cluster Storage Environments, Hitz et al. File System Design for an NFS File Server Appliance, Rosenblum, Ousterhout. The Design and Implementation of a Log-Structured File System
Fault Tolerance, Journaling, and Soft Updates
Material: Prabhakaran et al. Analysis and Evolution of Journaling File Systems, Seltzer et al. Journaling Versus Soft Updates: Asynchronous Meta-data Protection in File Systems
Advanced Hashing: Consistent Hashing, Share, and Crush
Material: Karger et al. Consistent hashing and random trees: distributed caching protocols for relieving hot spots on the World Wide Web, Weil et al. CRUSH: controlled, scalable, decentralized placement of replicated data
Caching, Replication
Material: Nelson et al. Caching in the Sprite network file system, Kistler et al. Disconnected operation in the Coda File System
Consistency, Availability, and Partition Tolerance
Material: DeCandia et al. Dynamo: Amazon’s Highly Available Key-value Store, Helland, Life beyond Distributed Transaction: An Apostate's Opinion
Data Deduplication
Material: Muthitacharoen et al., A Low-bandwidth Network File System, Douglis, Iyengar. Application-specific Delta-encoding via Resemblance Detection
Performance Analysis
Material: Traeger, A nine year study of file system and storage benchmarking (at least parts of it)

As books I would recommend:

Callaghan. NFS Illustrated
Pate. UNIX Filesystems: Evolution, Design, and Implementation
Folk, Zoellick. File structures

For me, a few key points are important:

To clearly separate between classes of file systems and a concrete example. The best example is the class of network file systems vs. NFS. At the end there should be no much question if something is a inherent property of a class of file systems or of the concrete implementation
To have enough time to handle the basic concepts independently from concrete usages. For example explaining B-Trees as an important file structures independent from the usage in e.g. BTRFS.
The concepts are more important than the current technology or standards.

Storage System and File System Courses

2009-12-01T00:06:00.000-08:00

I researched a lot about storage system classes given at good universities this year. This had two reasons: The first was this post of a researcher at NetApp, about the missing of a good storage or file system class book and secondly our own storage systems class where I was the TA.

In this post I want to give a short overview about the various different courses, their focus, and other things. Please note, the following text might contain errors or misconceptions on my part. I also might have missed other storage courses at these universities.

University of California, Santa Cruz:

Storage Systems, Winter 2008:
http://www.soe.ucsc.edu/classes/cmps229/Winter08/

Let's begin with the course of the University of California in Santa Cruz. Storage is a huge at UCSC with the Storage Systems Research Center that partners with nearly very everyone. The ceph file system and the crush hash function are two outcomes of their research.

The course consists of a series of lectures (two per week), lots of reading material, and a project. The lectures are about file systems beginning with uniprocessor filesystems, performance analysis and (very fast) to distributed filesystems. They also cover fault tolerance and other advanced topics. Their reading material consists of 37 papers from classics like "File System Design for an NFS File System Appliance" to state of the art research papers like "An Analysis of Data Corruption in the Storage Stack" (FAST 2008) that come about two weeks before.

I miss some important basics that IMHO are important for understanding storage system design, like properties of modern hard disks and I am not that into archival storage (my boss is), but it is a really good designed course. Unfortunately, the lecture slides are not available online.

Columbia University, New York

Advanced Topics in Network Storage Systems, Spring 2004:
http://www1.cs.columbia.edu/~magoutis/cs699810-spring04/index.html

I may have missed one, but the last storage related course at Columbia University had been in 2004 by Kostas Magoutis. The course is focused on network storage and probably relies on basics from an Operating Systems class or a basis storage class. The lectures had been one per week with one to three papers are reading material per week.

Really nice is that the lecturer has posted notes how the read the papers with questions and annotations to some of the material. Interestingly, data deduplication is covered with the LBFS, the Venti paper, and Henson's Compare-By-Hash papers.

There are three books recommended for the course "UNIX Internals (1996)", "The Design and the Implementation of the 4.4 BSD Operating System (1996)" and "NFS Illustrated (1999)".

Cornell University, New York

Advanced Distributed Storage Systems, Spring 2009:

http://www.cs.cornell.edu/courses/cs6464/2009sp/

At the Cornel University, I found the course and advanced distributed storage systems by Hakim Westherspoon (has taken part in the OceanStore project). The lectures, given two per week, handle "Cloud Computing, "Network File Systems", the important topics of Consistency, Availability, Replication, and Scalability.

I think the major strength of this course is that it seems to focus much more than the other courses and the important concepts needed for storage system design, implementation and research than the focus on standards, products, and storage management issues. The major weakness is that the individual lectures are very focused on the research papers, whose content is presented. Even to the point that there is no single presentation scheme. I think the overall consistency of the lecture is weakened this way.

One interesting aspect of the course is that the students have to write and hand-in short summaries of the reading material papers consisting a summary (3-4 sentences), two or three major strength points, two or three weaknesses and one question of future work that should be followed in the option of the student.

The have to projects as part of the course: In the first the students have to develop a distributed file system based on Amazon Web Service infrastructure. the second is a research project, the students have to come up with by themselves.

For the course 6 books are recommended: Two books by Richard Stevens (UNIX Network Programming, Advanced Programming in the UNIX Enviromment), two books by Tanenbaum (Modern Operating Systems, Distributed Systems), "The Design and Implementation of the 4.4 BSD Operating Systems", and "The C++ Programming Language" book by Stroustrup.

John Hopkins University

Storage Systems, Fall 2007:

http://hssl.cs.jhu.edu/~randal/419/sched.html

At the John Hopkins University -- where our professors of Christian Scheideler and my advisor Andre Brinkmann (as visiting PhD student) had formerly been -- I found the Storage Systems course by Randal Burns.

As usual the course consists of a lecture series (2 lectures as 50min per week), home works, and a project. I like that the course some basics like disk drive architecture that a essential to understand the design of storage systems. On the other side it is a bit short on distributed file systems.

University of Notre Dame:

Distributed Storage, Fall 2005:
http://www.nd.edu/~surendar/teach/fall05/cse70481/index.shtml

The University of Notre Dame offered in 2005 the course "Distributed Storage" by Surendar Chandra.

As usual the course consists of a series of lectures (2 per week) and a project. The lectures topics are "Naming and location", "Consistency and Replication", "Distributed Storage Management", "Security", "Peer-to-Peer Storage and Sensors", and "Energy Management". The reading material consists of not less than 40 papers. My impression is that the collection of reading material differs much from the material of the other courses covered here, e.g. the well-known "classical" papers are not linked.

Technion:

Filesystems, Spring 2009:
http://webcourse.cs.technion.ac.il/234322/Spring2009/

Technion is the "Israel Institute of Technology" in Haifa and I said before: I am pretty envy to the students there. However, not especially because of the "Filesystems" course.

The lecture series consists of an short introduction on disk drive architecture, RAID, sequential data processing on tapes (hey, I infer here from the pictures in the slides only), disk-based sorting, B-Trees, Hashing, concurrency and transactions as well as recovery.

The course recommends five books: "File Structures and Analytic Approach", "Transactional Information Systems", "Principles of Database and Knowledge-Base Systems", "Database Management Systems", and "Database System Implementation". None of these books are directly filesystem related. The books match exactly to the lectures, mostly related to the basics shared between databases and storage systems, but nothing directly related to file systems.

The assignments seem to be pretty similar to ours. It seems to consist of multiple assignments about an easy filesystem implementation. However, the assignments are given also in Hebrew, so I don't understand them. I expected more from a Technion course.

University of Wisconsin in Madison:

Advanced Storage Systems, Spring 2006:
http://pages.cs.wisc.edu/~remzi/Classes/738/Spring2006/

The advanced storage systems class given at the University of Wisconsin seems to be a nicely structures class with interesting topics: It begins with local storage systems, but moves very quickly (3. topic) to distributed and mobile systems. Then important concepts like reliability and fault tolerance, performance and scalability as well as caching, replication and consistency are discussed. The reading material is a nice list of now classics like the WAFL paper, the AutoRAID paper, the GoogleFS and MapReduce, but also Row Diagonal Parity and the "soft update" paper.

What universities are missing:
The University of California, Berkeley is missing: The home of BSD (and therefore the Fast File System), RAID, and a lot of early work in P2P storage seems to have no course focussed on storage or file systems. I could not find classes in Stanford, Harvard, MIT, and Carnegie Mellon.

Summary

To sum these courses up a bit: Most courses have large amounts of reading material. This is unusual in Germany (or at least at UPB). I had enough courses (especially in the SE part) without any reading material: We followed this "US style" in our course, but only with 12 papers. Most courses have a project assignment for the students where the students have to come up with an own topic. I really like this, too.

Our own courses

Storage Systems (German), University of Paderborn, Spring 2009:
http://pc2.uni-paderborn.de/teaching/lectures/speichersysteme/

"Our" own storage systems course consists a lecture series with 15 lectures a 90 min and 6 assignments.

The lecture starts very slow, with "Magnetic Storage Systems" (week 1), Disk Scheduling (week 2), an introduction in MEMS and Flash storage (week 3), and RAID (week 4, 5). Next came filesystems (6,7) and storage connection technologies like SCSI (week 8) to SANS (week 9). Network and parallel file systems are treated in week 10 - 12.

The assignments consisted of programming small FUSE filesystem in C (step-by-step).

In the last third of the lecture, the courses treated advanced storage topics that are interesting for our current research project like Long Term Archiving, HPC IO (MPI IO), Contentious Data Protection (CDP), Data Deduplication and P2P Storage.

In addition to the reading material, we referred to the book "Linux Device Drivers".

Our professor, Andre Brinkmann also gave a short course (6 lectures) called "Theoretical Aspects of Storage Systems Research" at the Politechnika Wroclwska in Poland, which is a very condensed version of our course focussed on the theoretical aspects.

Last words:

I really liked studying and comparing the storage system lectures. These lecture provide a pretty good overview about the classical (I should call them "essential") research papers of our field and an overview about related books as long as a real storage system course book is missing.

I am impressed that so many universities have "project" assignments where the students have to come up with a topic by themselves. These lectures show want is possible on good (mainly US-) universities, with motivated students, and with the right foundations.

Travel report: Israel - Haifa, Jerusalem, and Tel Aviv

2009-07-20T15:04:00.000-07:00

In the first weeks of May I visited Israel to take part at the SYSTOR 2009 systems conference. The conference, which was hosted by the IBM Research Labs in Haifs, concerned about different systems aspects, but had also a deduplication track consisting of three talks. It was a nice trip and this post covers the "business" -- meaning the conference -- as well as thoughts about my private travel trough the country after the conference.

Israel Travel auf einer größeren Karte anzeigen

Day 1 - 4: Haifa

The first day was hard. I arrived at 3 o'clock in the morning at Ben Gurion Airport in Tel Aviv. I had read that bus transportation is the major inter-city way to travel. So I expected a larger bus station (as I later saw in Jerusalem and especially Tel Aviv), I found that station. I waited there for around 4 hours. Then a journey through the country. I sometimes had no idea were I was, but I am pretty sure that it was not the direct way to Haifa. It was the first time in a country that is not using latin letters. The hebrew letters seemed like random noise to me. I was never good in learning languages. The start in Israel was therefore a bit rough.

The SYSTOR conference on the other hand started in the nice and friendly location of IBM Haifa Labs, near the University of Haifa. The conference is pretty small. 24 accepted papers, around 50 visitors. But some talks were really interesting, others were disappointing. I liked e.g. Ethan Millers talk about deduplication of virtual disk images. He presented no really unexpected results, but to have the information what is important and what is not is nice to have written down. I was disappointed by some of the industry talks. Some were much too marketing driven and not deep enough in the technology I was really interested in. An example for this was the talk of Mellanox.

At the second day I presented the results of the first half of my master thesis. Presenting at a conference, was totally new to me. I think that my presentation was pretty good. I think -- at that is important -- the audience understood my major points. The paper version of the talk I gave is online in the ACM Digital Library.

But presenting a topic you know and were you had the opportunity to train, is one thing. Smalltalk and networking is also important and at such a small conference it is much easier. I e.g. meet a researcher whose blog I read even before SYSTOR. Surprisingly many people ask me about the blog and twitter. I really liked the "social event" that took place in the old city of Caesarea, the city from that the romans governed the ancient Palestine and a crusader fortress. Extremely cool view at sunset. Unfortunately I have no photo of it.

One funny story: The title of the conference was "SYSTOR - The Israeli experimental systems conference". The Israel Defense Forces (IDF) obviously misunderstood the focus on computer systems research and send an IDF soldier who is also a biology researcher to visit the conference. She probably understood pretty nothing as I would understand nothing on a biology conference.

IBM is not the only cool company in Haifa. Nearly every top company has a engineering facility there: NetApp, Google, Yahoo, LSI, and many others. SAP has an office in another town near Haifa. So I am pretty envy to the students of the Haifa university or the technical university of Israel, Technion. They have more CS-related top companies in their city than we have in complete Germany.

Day 5 - 7: Jerusalem and Dead Sea

After the conference, I stayed another week in Israel. From Haifa, I went to Jerusalem - A pretty extreme city. Everything is about religion there. As a mainly secular liberal (in an european sense), it was pretty strange and I want never ever live in that city.

On Saturday (Sabbat) my impression was that the city is practically shutdown. Every restaurant is closed, the streets are pretty empty (only Sherut taxis are driving). As tourist you better buy water on Friday, or you have a problem. This is totally different from Tel Aviv, were the life is much more relaxed and the people go to the beach on Sabbath. To read articles about problems between the "Jersusalem Life Style" and the "Tel Aviv Life Style" in the newspaper is no surprise after seeing both cities, e.g. here at spiegel.de.

I know the amount of history located in the old city, but I didn't liked visiting it. Too much persistent souvenir traders and shady tourist guides. I really don't like that. Especially in the Christian and the muslim charters. I haven't seen them in the jewish charter. May be only because it was Sabbath and than even dubious souvenir trades have their free day. Please: If you consider something your "Holy Place" show some dignity.

After noticing that every direction sign towards the Western Wall (what we call "Klagemauer" in German) is intentionally misleading, I oriented myself only by my "Lonely Planet". Eventually, I found the western wall plaza -- the only place in the old city that has been left its dignity. Mainly because the rules stated on large signs allow the prayers not to be distributed too much be people like me (no photographs on Sabbath for example). I was impressed how near all these locations are in reality. The Western Wall, the Temple Mount, the Al-Aksa-Mosque. Wow.

On my second day to Jerusalem, I had a day trip to the Dead Sea. The "Lonely Planet" says that the "Ein Gedi Beach" is an "undeserved popular beach". The book is right. Dear reader, I you visit the Dead Sea, please, drive one Egged-Station further. The "Ein Gedi Spa" is probably what you want visit. However, swimming in the Dead Sea was awesome. Totally strange feeling to be pined on the surface. I knew photos of people reading newspaper in the Dead Sea, but I never really took it for real. I always thought that it maybe is a bit easier to by on the surface, but can really can read while swimming. We should try playing Water Polo in the Dead Sea.

Days 8 - 11: Tel Aviv

After a dose of "culture" in Jerusalem, I went to Tel Aviv. And Tel Aviv is really a nice city. While I had problems in Haifa and Jerusalem to find restaurants to trust and to find a super market, both was easy in Tel Aviv. The shopping streets were fun - at least after you accept that it is normal that crowds of cute girls in uniform, jump up and down, shiekingly, before Bikini shops.

The beach was great. The 6-km promenade to the old city of Jaffa (the oldest documented habour of the world) was great. I visited the university of Tel Aviv. Palms on the university ground. Much of green. Have I said that I was sometimes pretty envy to the students there?

At the time I visited Tel Aviv, you can stay at the beach and swim, but the beaches were pretty empty. So I visited two museums in Tel Aviv. The Diaspora Museum at the university (Diaspora is the time called when the Jewish people had been in exile) and the Hagana Museum at the Rothschild Boulevard near the Independence Hall. Even considering that the Hagana Museam is pretty biased, it help to filled some holes I had in the understanding of the history of the country. The history of Jewism/Palastine/Israel is not a topic in German schools between the time between the year 70 and 1933 and also not after 1945. I suppose most people in Germany think that 1933ff was the first time that Jewish people returned to their country. However, I don't want to blame the schools for that. Class time is limited. Even the history of Germany after 1945 is not a topic in German schools.

I stayed at the Prima hotel. Nice, perfect location directly at the beach, but in contrast to what is said in the "Lonely Planet" there is no free internet. Only terribly expensive WLAN.

I really liked Tel Aviv and would it be so expensive I would revisit it, for sure. Some kind of local travel guide would be nice next time.

More random notes

My return to Germany from Ben Gurion Airport has been more eventful than expected. Some presents I bought at Tel Aviv, attracted the suspect of the security staff and I got into a extensive security check using some high-tech explosive detection devices. I had to show that my MBP and my photo camera really works. I had to remove the battery, etc. They even checked by "dirty clothes bag" for explosives. Fortunately the atmosphere was pretty nice e.g. the security staff found my "english-hebrew" book interesting and apparently found some of the translations pretty funny. Totally cute was that one of the security girls carefully re-packed the gifts, which they checked in detail, back into a box. The wrapping was nicer afterwards than before.

One thing I found very strange at the beginning: There are soldiers with armed weapons everywhere. Not because of checkpoints (I have only seen one checkpoint near the Dead Sea), but because it is normal to wear uniform in the spare time and often to wear the personal weapon. I have done mandatory military service as mechanized infantryman in 2000/2001. In the Germany army, soldiers are very strict when it comes to weapons. Wearing an assault rifle in the sparse time is completely unthinkable in Germany. For example, recent newspaper reports state that soldiers that have forgotten to leave the personal pocket knife(!) at the barracks and get controlled by the police have to pay up to 10.000 Euro (14.000 USD) due to very strict German weapon laws. From a military point of view, it also clear why the IDF soldiers carry their weapons to their home. Similar to Switzerland, the country is simply to small to have time of a lengthy mobilization in case on an attack. But, it wired. Even wearing the uniform in the sparse time is only allowed under very strict rules. A soldier is only allowed to wear the uniform on the direct way from home to the barrack. I have seen a couple walking through the city park of Jerusalem, holding hands on Sabbath, and the man had a rifle on this back. Nothing unusual there.

Other thing about the IDF soldiers I found strange, is -- I would call it -- lack of discipline. They hang around at bus stations, making themselves up with a lipstick, chewing gums, wearing non-uniform clothers like Flip-Flop shoes or (as described above) do shopping in groups. Some female soldiers had opened their shirt by the top three or four pates. All nothing that would be considered appropriate here. While I was pretty fast used to see uniforms everywhere, the lack of discipline kept surprising me.

Eating: I love english breakfast, so an Israeli breakfast is probably some kind of counterpart. Due to religious rules, they do not eat meat, eggs, ... for breakfast. The fresh salads, fruits, and cakes were really nice (at least in good hotels), but I still missed my favorite topping (ham). I am not really a fan of marmalade. The rest of the eating I would consider "arabic" (Probably Israeli people will scream when reading this): Hummus (delicious!), Kuskus, and these extremely sweat cakes. Falafels seem to be some kind of national disk.

I have not fully get what "Kosher" really means, but nearly every restaurant I found had "Kosher" certificate. It is still really important there. But at least in Tel Aviv, there are also non-kosher restaurant, e.g. -- if I understand if correctly an italian restaurant is by definition non-kosher. In practice, e.g. at the cantina of IBM, I haven't found the Kosher thing anything limiting except for the breakfast.

Kleine Erinnerung daran über Israel zu schreiben

2009-06-25T12:24:00.000-07:00

Heute kam per lawblog.de eine kleine Erinnerung einen Reisebericht über Israel zu schreiben:

Bei Polizeikontrollen, vor allem in Schleswig-Holstein, sind nämlich Soldaten außerhalb des Dienstes mit einem juristischen Vorwurf konfrontiert worden: Verstoß gegen das Waffengesetz. Ihr Vergehen? Die Soldaten, meist in Uniform auf dem Heimweg ins Wochenende, hatten das “Standardmesser” der Bundeswehr dabei.

Es handelt sich um ein Taschenmesser (Hersteller: Victorinox), allerdings in Form eines Einhandmessers. Die Besonderheit an Einhandmessern ist, dass sie mit einer Hand geöffnet werden können. Problem: Einhandmesser fallen seit neuestem unter das Waffengesetz. Wer so ein Messer bei sich hat, riskiert ein Bußgeld bis zu 10.000 Euro.

Auf so etwas kann man nur in Deutschland kommen, oder?

In Israel -- und zum Glück ist Deutschland im Gegensatz zu Israel von Freunden umgeben -- sieht man überall Soldaten mit ihren Waffen auf dem Heimweg und auf dem Weg zur Kaserne. Oder auch am Sonntag beim Spaziergang mit der Liebsten im Park.
Es war sehr gewöhnungsbedürftig und ich bin froh, dass dies hier weder notwendig noch üblich ist, aber wegen dem "Standardmesser" einen Aufstand zu machen, darauf kann man nur in D kommen.

dirkmeister.de down?

2009-06-20T00:09:00.000-07:00

Der Webserver, auf dem auch dirkmeister.de gehostet wird, hat zum dritten Mal innerhalb von einem Jahr einen Hardwaredefekt. Nachdem daher sicher sinnvollen Hosting-Providerwechsel läuft aber nichts wirklich richtig: Kriege die Domain nicht umgezogen, keinen vernünftigen Zugang zum neuen Server, etc.

Auf Grund dieser Probleme ziehe ich jetzt erstmal nach Blogger um. Ich habe ein Jahr gebraucht um nach dem letzten Crash wieder die Leserzahlen zu erreichen wie vorher. The Show must go on. Wenn hier irgendeine Festplatte crashed, ist es mir total egal. Wenn es mir "hier" gefällt, dann bleibe ich möglicherweise auch ganz bei Blogger.

Auch andere Webseiten sind aus dem gleichen Grund down. Zum Beispiel der Blogaggregator juli-blogs.de. juli-blogs.de ist nicht down, weil ich bei den "Jungen Liberalen" ausgetreten bin. Das war nur eine unglückliche zeitliche Überschneidung. Ich habe keinen Plan juli-blogs.de einzustellen.

Twitter Updates 2009-04-27

2009-04-26T04:32:00.000-07:00

Wow. Oracle buys Sun! Changes: More wired version numbers for Sun products? Future of mySQL? Oracle is more anti-agile than IBM. #
Listening to "Storage Systems". #
My Prof. has read the Scala book during holiday and finds the language nice. Maybe we will use it more at the PC^2. That would be nice. #
Nice overview about Cloud Computing (including OSS) in current "Linux Magazin" (German). I would like to eval "Eukalyptus". #
Removed a very hard to track bug in my master thesis's dedup system (ok, I introduced the bug after the thesis). I like this part of my job #
Another talk about deduplication from Santa Cruz that seems interesting: "Data Sequentiality Potential for Data De-Duplication Schemes". #
Searching the current mailing address of Peter Levart, project owner of FUSE-J. Sad that the project seems to be abandoned. #

Twitter Updates 2009-04-19

2009-04-19T04:32:00.000-07:00

Oh. For weeks no response from my hotel in Haifa. Today both hotels responded within 30 minutes. #
Playing with FUSE-J. Problems with C generator. It finds method with same name, same parameters but different return type: ByteBuffer.array #
Visited a PhD defence of a fried today. :-) #
" Who want to write a paper for next year, "grep vs reverse index"?" on Hadoop mailing list: http://tinyurl.com/delgj2 Lol #
Just installed my Intel X25-E SSD. #
The grading of my master thesis is now finished. Finally i'm really done. Nice. #
Today I played soccer organized by the PACE international graduate school. Finished as 8th of 9 teams. Oh. #
SSRC Seminar talk by Deepavali Bhagwat "Extreme Binning: Scalable, Parallel Deduplication". I would like listening to this talk. #

Twitter Updates 2009-04-12

2009-04-12T04:32:00.000-07:00

Now I have open my first open source project. My first OS activity since the bad experience with the Shox network simulator last year. #
Just watched Monster vs Aliens in 3D. Not the best Pixar movie, but the 3D experience was "Wow". I bet most films will be 3D in a few years #
Listening to Google Collect episode of the Javaposse. Used the library in Shox project two years ago. Nice engineering! #
The hotel in Haifa I picked first doesn't respond to my mails. One mail two weeks ago. One two days ago. Strange. Now I try an other one. #
Quillen: Nice deduplication project using AWS S3 on Google Code: http://code.google.com/p/quillen/ #
Statebook: http://www.statebook.co.uk/ #

Just Released: Filesystem Chunking

2009-04-06T04:38:00.000-07:00

I just released some tools developed to evaluate chunking-based data deduplication techniques on various systems and to evaluate new chunking methods into the new open source project "fs-c" (for filesystem chunking).

The fs-c tools allow to analyze the internal and temporal redundancy of file system directories that are found by content-defined chunking using Rabin's fingerprinting method and static chunking with different chunk sizes.

The goal is to allow users to provide a rough estimate of the redundancy found by de-duplication systems for their concrete workload and to provide a basis for further enhancement to the tools and for e.g. application-specific chunking methods.

Currently the analysis is only done using an in-memory hashtable which limits the size of the system to a few hundred GB of data (or you need a large shared memory systems). I have also developed Hadoop MapReduce tasks to calculate the redundancies, but that code is not ready to publication.

Twitter Updates 2009-04-05

2009-04-05T04:32:00.000-07:00

in Willingen for the PC^2 Seminar. Listening a talk about "Scientific English" #
I'm aware of lots of storage research paper from NetApp, IBM and HP. I know some from Sun. Are there are any from EMC I should be aware of? #
Something sucks here. Scalax and/or Scala Eclipse Plugin. OutOfMemoryException (on my 4 GB MBP) while simply compiling this project. #

Comparison of One-Hop Distributed Hash Tables (DHT)

2009-04-02T08:44:00.000-07:00

I just uploaded an old semester work, which I haven't published here yet, about a comparision of One-Hop DHT:

Distributed Hash Tables (DHT) are an important substrate of several peer-to-peer (P2P) applications. Most existing approaches favor a small memory and network overhead over lookup latency. New approaches question this tradeoff and allow a lookup with using only one hop, but they store the routing information for all nodes on each node in the system and so require higher background traffic to maintain the routing tables up-to-date. In this paper the design of three one-hop DHT approaches is described and compared in detail. This comparison shows that different assumptions are used to analyze the approaches. Therefore, several parameters are inspected and an uni- ﬁed parameter setting is extract. Using the uniﬁed parameter setting, a fair and meaningful comparison of the approaches is possible. In particular, the bandwidth consumption, fault tolerance properties, the usage of heterogeneity in the P2P network, and the scalability are compared. The comparison shows that the unified parameter setting lead to different relative results as originally stated by the approach designers.

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