Friday Apr 20, 2007

Get Feisty Fawn, Get Java!

So Ubuntu Feisty Fawn (7.04) has been released. I've developed JDK on older version of Ubuntu for a while, this is a chance to give latest Ubuntu a try.

And guess what, you can apt-get JDK the whole Java stack from Sun! Isn't it fantastic? At the same time downloading Feisty Fawn, you may also want to check out more informations about Java on Ubuntu here, or here.

Wednesday Feb 28, 2007

Linux/IPv6 can't talk to itself?

If I remember correctly, USAGI stack should have been intergrated into main-stream Linux kernel since 2.4 era. So IPv6 things should work out-of-box on my 2.6 box, at least basic stuff like TCP or UDP communication over IPv6... But wait, there's big surprise I just found. That is, seems it can't talk to itself through its own IPv6 link-local address, for both TCP and UDP! Using any textbook code snippets - one to send data, and the other to try to receive it. You can see that data just vanish into the void. What's more interesting is that if sending data from another machine to that same address, all data will be received.

My guess is that there's some route issue inside kernel. Linux or USAGI guru out there, any hints?

Saturday Oct 22, 2005

Where is my five rings?

Quoted from Asterisk: The Future of Telephony:
...The most successful key telephone system in the world has a design limitation... when you determine the number of times your phone will ring before it forwards to voicemail, you can choose from 2, 3, 4, 6, or 10 ring cycles. Have you any idea how many times people ask for five rings? Yet the manufacturers absolutely cannot get their heads around the idea that this is a problem. That's the way it works, they say, and users need to get over it.
And another story:
...the name you program on your set can only be seven characters in length. Back in the late 1980s, when this particular system was built, RAM was pretty dear, and storing those seven characters for dozens of sets represented a huge hardware expense. So what's the excuse today? None. Are there any plans to change it? Hardly—the issue is not even officially acknowledged as a problem.
Funny. Comparing to that situation, customers today are a little spoiled \^_\^

Friday Oct 14, 2005

NIS auth and Ubuntu group

Trying to build the whole java workspace on Ubuntu 5.10 now. The first step is to get Ubuntu work smoothly inside SWAN of course. So far everything works fine, e.g. autofs, except one small issue. It seems that a NIS user has limited privileges locally. He can't access audio device, for example. It's quite annoying.

It turns out to be a known issue, though. Check this tip out. It's cool, Guillaume.

Monday Oct 10, 2005

Andy Bechtolsheim on podcast

Check it out:

Monday Apr 18, 2005

Root patterns of asynchronous messaging system

Gregor Hohpe from ThoughtWorks talked about asynchronous messaging in TSS. It's informative. For example, Gregor identified 6 so-called root patterns:
  • channel
  • message
  • routing. Loose coupling means making less assumptions so we also make no assumptions about where the message ends up.
  • transformation. Wants to integrate with existing system? Try translator pattern; it's all about how to transform existing data.
  • end point. End point is really the intersection between the messaging world and the object-oriented world - about how a Java application puts a message on the channel and how that connection point works.
  • system management, to address common challenges of system management, debugging and monitoring.
A very good guideline for anyone who wants to make a mind shift before being used to asynchronous stuff.

Monday Feb 28, 2005

Roy Fielding on Apache's 10 year anniversary

Roy Fielding gives his celebration to Apache's 10 year anniversary on apache mailing list.

And, this year is also the 10 anniversaries of Yahoo, Ebay, and Amazon. Netscape had its IPO 10 years ago. All these BIG names of Internet born at the same year. A little surprising, isn't it?

Plus, this year's (well, actually, it's last year) Turing Award is for Vinton G. Cerf and Robert E. Kahn. Can I say this year is the year of Internet, or the year of TCPIP? :-)

Saturday Jan 01, 2005

Infinite-precision real number in Java

It is a library from Hans Boehm of SGI. He calls it "constructive reals." Go taste it here. Not check it thoroughly yet, but definitely will do that later.

P.S. is that the same Boehm who developed a GC for C++?

P.P.S. There're several applet showcases of the library. I love the new Java applet splash when a applet lodaing.

Monday Dec 27, 2004

Tiger Poem by Joshua Bloch

I bet many of you have read Joshua Bloch's poem about Tiger. So how about a audio version of it? ;-)

For your convenience, I also post the poem here:

Tiger, Tiger Burning Bright
Like a geek who works all night
What new-fangled bit or byte
Could ease the hacker's weary plight?

To the most despised cast
We'll bid a fond farewell at last
With generics' burning spear
The need for cast will disappear

While Iterators have their uses
They sometimes strangle us like nooses
With enhanced-for's deadly ray
Iterator's kept at bay

When from collections ints are drawn
Wrapper classes make us mourn
When Tiger comes, we'll shed no tears
We'll autobox them in the ears

The int-enum will soon be gone
like a foe we've known too long
With typesafe-enum's mighty power
Our foe will bother us no more

And from the constant interface
we shall inherit no disgrace
With static import at our side,
our joy will be unqualified

O joyless nights, o joyless days
Our programs cluttered with arrays
With varargs here, we needn't whine;
We'll simply put the args inline

And as for noble metadata
I'll have to sing its praises later
Its uses are so numerous
To give their due, I'd miss the bus

Tiger, Tiger burning bright
Like a geek who works all night
What new-fangled bit or byte
Could ease the hacker's weary plight?

Sunday Dec 26, 2004

There's always something interesting

Just read something entertaining, copy it here:
A physicist, an engineer, and a computer scientist were discussing the nature of God. "Surely a physicist," said the physicist, "because early in the Creation, God made light; and you know, Maxwell's equations, the dual nature of electromagnetic waves, the relativistic consequences..." "An Engineer!," said the engineer, "because before making Light, God split the Chaos into Land and Water; it takes a hell of an engineer to handle that big amount of mud, and orderly separation of solids from liquids..." The computer scientist shouted:" And the Chaos, where do you think it was coming from, hmm?"


ps. discovered Sun Net Talk Program. It's a must to visit.

Tuesday Nov 09, 2004


Today read RFC 2396 about URI syntax. I found RFC is subtle, for example:
In general, a character is reserved if the semantics of the URI changes if the character is replaced with its escaped US-ASCII encoding. -- section 2.2
Implementers should be careful not to escape or unescape the same string more than once, since unescaping an already unescaped string might lead to misinterpreting a percent data character as another escaped character, or vice versa in the case of escaping an already escaped string. -- section 2.4.2
These can be real bugs in specific implementation! RFC is RFC. If one get to read it, read it very carefully :-)

Monday Nov 08, 2004


If you cannot read this entry, try making your browser to switch to "UTF-8" encoding.

Anyway, settled down at last. "Life is short. Be assertive". It's time to Tiger, Mustang, and Dolphin.

Monday Nov 01, 2004

The Blacksmith and the Bookkeeper at is full of wonderful articles. This 3 installment article is such one.

It's a article with serious thoughts, I think. It's interesting, too. Read this (I just copy and paste it):
The on-board Apollo Guidance Computer (AGC) was about 1 cubic foot with 2K of 16-bit RAM and 36K of hard-wired core-rope memory with copper wires threaded or not threaded through tiny magnetic cores. The 16-bit words were generally 14 bits of data (or two op-codes), 1 sign bit, and 1 parity bit. The cycle time was 11.7 micro-seconds. Programming was done in assembly language and in an interpretive language, in reverse Polish. Scaling was fixed point fractional. An assembly language ADD took about 23.4 micro-seconds. The operating system featured a multi-programmed, priority/event driven asynchronous executive packed into 2K of memory." -- Apollo 11: 25 Years Later by Fred H. Martin, Intermetrics, Inc., July 1994
For short it's about an OS within 2K memory! Totally crazy from today's point of view :-)

Sunday Oct 31, 2004

My SunRay story

SunRay is my first machine when I was on board at Sun, you know. I use it and I like it. But until that time I became love it.

Here's the story: I sit in 11th floor of office building. As a new hire, I still have many things to take care of. On day, I think it was some day of last week, I came to Carnegie Hall of 10th floor to do something. I must waited there first. There's nothing to do. So I logged into one SunRay there. Wow! My whole desktop came back and the whole seesion remained the same. It's really amazing! SunRay's vision about mobile desktop is cool.

Hello, blogging world!

This week is my third week at Sun China ERI. I work as a member of Java Security and Networking team. There still have many things to know. But eventually, my work environment here is getting ready.

Actually this is my first try of blogs. Communication is always fun.

So far for the first blog post.



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