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Jakob Jenkov
Works at Jenkov Aps (jenkov.com)
Attended IT University of Copenhagen
Lives in Barcelona
4,587 followers|943,748 views
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Jakob Jenkov

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Fail by Ninja
If you ever played any ninja computer games, and like fail videos, this 5 minute video is actually pretty funny :-D
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Lock Free Queues
This talk talks about some of the challenges of implementing lock free queues in Java. Quite interesting!
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Java Performance Tips
I will start collecting performance tips for Java on my tutorial website soon. First the basic stuff, then later more advanced stuff. I will collect from the masters who have actually implemented high performance systems like Martin Thompson, +Rick Hightower and others, and mix my own experiences from our http://vstack.co project.

If you have Java performance tips you want to share, feel free to send them to me! Or links etc.
Why VStack.co ? Some hosted application stacks are merely collections of existing products made available as a bundle. For instance, an existing SQL / NoSQL database, file storage service, message queue, XMPP server etc. While this is an easy way to quickly provide a wide collection of services, ...
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Designing for Performance
Another interesting presentation by Martin Thompson about designing software for high performance.
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Vert.x Command Line Tutorial
This new text in my Vert.x tutorial explains how to deploy verticles from the command line with Vert.x . Using the command line you can deploy verticles written in different programming languages into the same Vert.x instance.

#vertx
It is possible to run Vert.x from the command line and deploy your verticles from the command line too. This tutorial explains how to run Vert.x and deploy verticles from the command line.
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+Zx Su I have made my own which fits my website exactly.
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Java volatile Keyword Tutorial - Updated
I have updated my Java volatile keyword tutorial. Now it also explains the happens-before guarantee of the volatile keyword, as well as better explain what volatile guarantees and does not guarantee (when synchronized is needed).

#java
The Java volatile keywords guarantees variable visibility across threads, meaning reads and writes are visible across threads.
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ouais bon je vais continuer à utiliser des EJB :p
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Have him in circles
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Jakob Jenkov

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3D Crosspoint Memory
The speed of DRAM, the capacity and price of a disk, and non-volatile (not erased when powered off). In-memory technology is about to kick some real ass. Up to 1000 x the speed of a normal hard drive!
See 3D XPoint™ technology unveiled—a breakthrough in non-volatile storage technology that is cheaper than DRAM and faster than NAND.
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Great talk :-)
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In-memory CMS - v. 1.0.0
Following my new "obsession" with keeping everything in-memory, I have developed a small in-memory CMS system which I will be using on  new web projects pretty soon.

Having all data in-memory of course makes the files be served faster to the clients (though you can argue whether that speedup makes a big difference in an anyways over-dimensioned server).

An in-memory CMS it also makes it easier to work with data. Data can now just be stored in JSON files and kept in a shared Git repository which everyone involved can edit (with full versioning and history etc.).

Finally, an in-memory CMS also makes it easier to implement a super fast search function for the data.

Granted, an in-memory CMS is not the right type of CMS for every kind of website, but for many websites which are primarily article / page based, or which display many data items of the same kind, such a CMS is just fine.
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+Kevin Sheppard Keep in mind that the websites I intend to use this with, do not have millions of pages (not yet). Even if they did, with text for millions of pages is no problem today. The images on the other hand, might represent a challenge (for millions of pages - not for my websites).
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Mythbusting Modern Hardware...
A 2 year old presentation about modern hardware from a software developers perspective. Still pretty interesting. Our hardware hasn't changed that much in those last 2 years.
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+Hua Zhang Yes, for sure. I will try to write some tutorials about all this in a near future. It's all pretty interesting, and there are lots of news for me.
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The Database Server is Disappearing
One of the trends I see in software development these days is, that apps no longer use a database server - e.g. an SQL database server. Memory is now so cheap that all data is kept in memory instead. That means you can create exactly the data structures that makes sense for your particular app - and not always use tables.

Changes to the database are flushed to a write log (redo log) which is read in from scratch when the app starts up. Log files are sometimes compressed into snapshot files which represents the state of the database at a certain point in time (all individual changes before that time are thus forgotten - but the snapshot contains the correct aggregate result of all those changes).

I will write more about this type of database trend in a near future. It's very exciting - it makes your app much faster, and much easier to code. Backups are incredibly easy as you just copy the write log files as they are produced.
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+Philippe Lhoste Thanks! I know about 3D XPoint RAM. It is very, very interesting!
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Ubuntu Linux as Web Server
I have updated my tutorial about using Ubuntu Linux as a web server. I have added a small section about how to install ufw if it is not already installed with your Ubuntu Linux distribution.

#linux  #ubuntu
This tutorial explains what you need to do use an Ubuntu Linux server as web server.
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Yeah.. Got it
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People
Have him in circles
4,587 people
王辉's profile photo
Vipin Kumar Tiwari's profile photo
Andrea Giassi's profile photo
Akshay Kamble's profile photo
Ricardo Pallás's profile photo
Imtiaz Ali's profile photo
Rupali Kanase's profile photo
Yoyo Chen's profile photo
Salman Ibadurrahman's profile photo
Work
Occupation
Entrepreneur, author, software developer
Skills
I have a master in IT (computer science) and 15+ years of programming experience. I have strong analytical skills, and I am strong at conveying ideas in an easy-to-understand fashion. I am not very good at being a boss, but I am working on that :-)
Employment
  • Jenkov Aps (jenkov.com)
    CEO, 2000 - present
Places
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Currently
Barcelona
Previously
Marbella - Copenhagen - Zurich - Svendborg
Links
Contributor to
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Tagline
Entrepreneur, author, software developer ( Jenkov.com )
Introduction
I am an internet entrepreneur, author and software developer, living in Copenhagen, Denmark (and partly in Barcelona, Spain). I share tips and tools about software development on Jenkov.com, as well as build various apps and open source projects.
Bragging rights
My tutorial website http://tutorials.jenkov.com has 300.000+ unique visitors per month and growing.
Education
  • IT University of Copenhagen
    IT (Computer science and related fields), 2003 - 2008
  • Roskilde University
    Computer Science, 1995 - 1999
Basic Information
Gender
Male
Looking for
Networking