top command in AIX

I keep looking up this piece of information repeatedly; hopefully I can find it here easily:

AIX has a command called "topas" that's a good alternative to the Linux "top" command

topas --help

topas -P

I have a new phone - the Samsung Galaxy Note 2

I usually tend to like simplicity - things that are minimalistic, purposeful, and worthwhile.

That's why I stuck to using a good basic phone all these years - first a Nokia 1100 and then a Nokia 1150. A phone is all I needed, and if I could get to buy a John's Phone in India, I would have gladly done so.

With all the news and buzz around smart phones, I kept observing and didn't find anything that would make me buy them in lieu of my basic phone, but finally this Diwali, I got a great product for which I could justify my purchase -- a brand new Samsung Galaxy Note 2.

I have a lot to say about this new purchase of mine. I really, really liked using it over the past couple of weeks. A single blog post would hardly suffice to describe the marvel that it is. For now, I will keep to a simple, short list of reasons that made me buy it.

Firstly, if you were to ask me "which, in my opinion, is a better phone - a Nokia 1150 or a Samsung Galaxy Note 2? ", I would pick the Nokia 1150.
I didn't buy Samsung Galaxy Note 2 because it was a better phone than Nokia 1150, I bought it because it was the best multipurpose personal gadget that I found in the market, and incidentally, it obviated the need for me to keep using the Nokia 1150.

A truly "multipurpose personal gadget"

Samsung Galaxy Note 2 is a fantastic, and in my view, currently the best multipurpose personal gadget out in the market, and here are the reasons:

1. It has the largest screen that can fit comfortably in my pockets - both of my trousers and of my shirt. A smaller screen would have made reading e-books, browsing web pages, and in general, any interaction with the device an inferior experience, and a larger screen would have made it impracticable to carry it around. It is therefore better than any other phone and better than any other tablet on this count.
2. It is not just a content consumption device - it is a marvellous content creation device too. Let me explain this a bit: Most mobile phones and tablets are good for consuming content posted elsewhere -- i.e., they are good for viewing videos, or reading books, or enjoying music, or reading email. There is usually little emphasis on the creation part. Anyone creating anything serious will do so on a full desktop or a laptop, not with a mobile phone. This, however, does not apply to the Samsung Galaxy Note 2, because of its useful stylus, the S-Pen. The S-Pen lets me take notes, draw sketches, take screenshots, annotate pictures, and do a whole lot more. I know of no other phone in the market that has a stylus as good as this.
3. It has a good battery life. This is not something that can be taken for granted, especially after I read a lot of scary reviews of inexpensive mobiles and tablets with bizarre battery behaviour.
4. It has an easy-to-extend, and open operating system - the Android. I find it particularly easy because I am already very comfortable with Java. Had it been the iOS, Symbian or Windows, I would have had a steep learning curve before being able to customize and extend my gadget.
5. It has a lot of sensors on board - Dual cameras, GPS, (and Glonass), Accelerometer, Compass, Gyroscope, much more than many other smart phones I read about. Every physical sensor gives a massive boost to the potential uses of the gadget.

In short, I have a lot to praise this device for. Thank you, Samsung for bringing it to the market :)

Secure JAX-WS with Apache CXF (Some links)

Some useful links for my reference, related to securing JAX-WS services when using Apache CXF:


Some background:

If you want to create a JAX-WS web service as standalone Java program (i.e., one that starts with a main(String..) method), there are two approaches:


1. If you can deploy your application on the Sun JVM, you can probably easily use Sun's HTTP server that comes bundled with it.
Something on the lines of:
KeyStore keyStore = KeyStore.getInstance("JKS");

keyStore.load..

KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance..

keyManagerFactory.init..

SSLContext sslContext = SSLContext.getInstance("TLS");

sslContext.init..

HttpsServer httpsServer = HttpsServer.create..

httpsServer.setHttpsConfigurator.. (pass the sslContext here)

HttpContext httpContext = httpsServer.createContext..

httpContext.setAuthenticator.. (for example, a BasicAuthenticator)

httpsServer.start();

Endpoint e = Endpoint.create(impl)

and e.publish(httpContext)


2. Instead, if you want you application to be portable and be able to run on any JVM, one way is to use an alternate JAX-WS implementation, such as Apache CXF.
Doing this would mean the following:
- Download the CXF distribution and add a large number of JARs that it needs to the classpath.
- If SSL and authentication is not needed, a simple one-liner is all that's needed:
http://cxf.apache.org/docs/a-simple-jax-ws-service.html#AsimpleJAX-WSservice-Publishingyourservice

- If SSL is needed, refer to the wsdl_first_https sample in the CXF distrbution, and set up a Spring configuration file to enable SSL on the embedded Jetty that CXF internally uses:
http://svn.apache.org/repos/asf/cxf/trunk/distribution/src/main/release/samples/wsdl_first_https
http://svn.apache.org/repos/asf/cxf/trunk/distribution/src/main/release/samples/wsdl_first_https/src/main/resources/ServerConfig.xml
And make your Java program use that Spring configuration:
http://svn.apache.org/repos/asf/cxf/trunk/distribution/src/main/release/samples/wsdl_first_https/src/main/java/demo/hw_https/server/Server.java

-If basic authentication is desired, add a Jetty handler to that Spring configuration file,

 <httpj:handlers>
        <beans:bean class="org.example.MyLoginHandler">
 </beans:bean></httpj:handlers>

where the handler MyLoginHandler extends ConstraintSecurityHandler, and in its constructor, initializes itself.
Some links on initializing a SecurityHandler:
http://wiki.eclipse.org/RAP/FAQ#How_can_I_use_Jetty_basic_authentication_in_my_application.3F
http://stackoverflow.com/questions/8056851/basic-authentication-with-embedded-jetty-7-server-and-no-web-xml-file

Miscellaneous references:
http://cxf.apache.org/docs/jetty-configuration.html
http://stackoverflow.com/questions/12423862/using-j2se-endpoint-with-embedded-tomcat

Five months of Linux

Back in April earlier this year, I made a decision to switch over from Windows to Linux. And now it's September - probably a good time to write about it.

It was my work Laptop that I decided to migrate to Linux. I use it all day at office for my regular job, and in that sense, it was probably a pretty risky decision.

Nevertheless, IBM, where I work, has good IT support for employees wanting to switch over to Linux. I got a custom Linux distro DVD from them (based on Red Hat), with a good lot of IBM software pre-installed. The installation went pretty smoothly, and I was up and running in a few hours.  


Do I miss Windows? Sometimes yes.

But only occasionally.

1. Look and feel

The Windows look and feel is certainly addictive - for someone who has used Windows for years together, it's natural to feel a bit uncomfortable in Linux - and I had anticipated this. Five months down the road, I feel quite happy with the Linux (GNOME) look and feel now.

2. Power management

Windows does a few other things better too - and the one that I realized a little late is its good power management capability. There's a little feature that goes by the name of "switchable graphics" that I got into trouble with when I moved over to Linux.

Basically if your motherboard has an in-built graphics controller and you also have a more feature-rich, but power-hungry discrete graphics controller attached, Windows makes a choice for your as to which one of these graphics controllers to use. If you're watching a movie or playing a game, probably you'd need the discrete controller, and for normal use, the in-built one is good enough.

My Linux, however, just kept using the discrete one all the time - draining out power quickly and heating up like a stove within a few hours of use. The fan control wasn't good either and I was very worried about it in the first few days of my Linux use. Thankfully, there was a way out in the BIOS setting of the motherboard that I could use to turn off the discrete controller altogether, and I sailed out of the problem.

3. Support for hardware devices

More generally, Windows seems to have better support for hardware devices.
  - My home printer, a Canon PIXMA, wouldn't work in Linux (there's no driver)
  - My phone, a Nokia, can't be connected to Linux (there's no PC suite for Linux)

With Linux, I always need to be ready for trouble every time I attach any hardware - be it a modem, or an internet data card, a camera or whatever. But for me, hardware support is not a very big deal. This is my work PC - I don't "need" to attach any phone, camera or portable printer to it per-se, I just "want" to, at times, and I can adjust to not being able to do so.

And why won't I switch back to Windows?

Well, to be honest, inertia is certainly one of the factors - I don't want to do all the backup/install/restore/get-accustomed-to business all over again. But that's neither the only factor nor the strongest one.

The way I instinctively feel that Windows looks good, and the way I feel that it works with any hardware I might plug in, I "feel" certain things about Linux too. I feel that my Linux is rock solid - I feel that it won't crash. I feel that Linux gives me the power to make my computer work for me.

Windows makes me feel that my computer is a friend of mine. Linux makes me feel that I'm the boss commanding my computer to do what I want.


Now to the details:

•  I have SELinux enabled.I have full disk encryption LUKS, as well as an Antivirus suite.

• I really adore ssh, scp, sftp, gzip, split and other wonderful utilities now. They are far better, faster, and natively integrated here in Linux than PuTTY and other clones that I had to use back there in Windows.

• Software installation and upgrades are a breeze. I found almost anything I needed in the GNOME package manager - from Octave (for data analysis) to Calibre (e-book reader), KColorPaint (much better than the Windows Paint) and many more.

• When building from source, it's almost impossible in Windows - I'd need to struggle with Cygwin and stuff like that. It's a trivial affair now in Linux.

• And I've really got used to the little widgets on my desktop panels - GNote, the GNOME Calc, the system monitor and so on.

• IBM software too work well and feel pretty robust in Linux (I have many of them installed to do my job - Rational Software Architect, WebSphere App Server, DB2, Lotus Symphony, Notes, Sametime, and others).

• I never need to worry about stuff like disk de-fragmentation, long file names, or accidentally deleting something in C:\Windows - (only on a handful of times have I had to switch over to root). Backups are easy too. I just tell Deja Dup to backup up my home folder and I can be sure there's nothing else scattered around all over the place.

And to conclude, at least for now..

Do I like Linux? Well, not the way I'd adore a beautiful sky with a bright sun and a rainbow on the other side. But I do like Linux the way I'd like the cockpit of a supersonic aircraft at thousand miles above the ground, with me inside.

Compiling Meep

Meep is a fantastic electromagnetic field simulator from MIT. [Link:ab-initio.mit.edu]

It runs fine on my Windows XP laptop, but my laptop isn't all that powerful to perform any meaningful simulations reliably. Fortunately I got access to a bigger 64-bit Linux machine that's got 128GB of RAM :) Installing Meep on it was a bit of a pain, though.. as I didn't have administrative access to that system, and finding the right versions of dependencies and compiling them with the right options was tricky.

Here's what finally worked for me:




mkdir --parents /home/kpachar1/meep/local

wget ftp://ftp.gnu.org/gnu/libtool/libtool-1.5.6.tar.gz
gunzip libtool-1.5.6.tar.gz
tar -xf libtool-1.5.6.tar
cd libtool-1.5.6
./configure --prefix=/home/kpachar1/meep/local
make clean
make
make install
cd ..

wget ftp://ftp.gmplib.org/pub/gmp-5.0.3/gmp-5.0.3.tar.bz2
bunzip2 gmp-5.0.3.tar.bz2
tar -xf gmp-5.0.3.tar
cd gmp-5.0.3
export LDFLAGS=-L/home/kpachar1/meep/local/lib
export CPPFLAGS=-I/home/kpachar1/meep/local/include
./configure --prefix=/home/kpachar1/meep/local
make clean
make
make install
cd ..

export LD_LIBRARY_PATH=/home/kpachar1/meep/local/lib

wget ftp://ftp.gnu.org/gnu/guile/guile-1.8.8.tar.gz
gunzip guile-1.8.8.tar.gz
tar -xf guile-1.8.8.tar
cd guile*
export LDFLAGS=-L/home/kpachar1/meep/local/lib
export CPPFLAGS=-I/home/kpachar1/meep/local/include
./configure --prefix=/home/kpachar1/meep/local --with-local-prefix=/home/kpachar1/meep/local
make clean
make
make install
cd ..

export PATH=$PATH:/home/kpachar1/meep/local/bin

wget http://ab-initio.mit.edu/libctl/libctl-3.1.tar.gz
gunzip libctl-3.1.tar.gz
tar -xf libctl-3.1.tar
cd libctl-3.1
export CPPFLAGS=-I/home/kpachar1/meep/local/include
export LDFLAGS=-L/home/kpachar1/meep/local/lib
./configure --prefix=/home/kpachar1/meep/local
make clean
make
make install
cd ..


wget http://www.open-mpi.org/software/ompi/v1.4/downloads/openmpi-1.4.4.tar.bz2
bunzip2 openmpi-1.4.4.tar.bz2
tar -xf openmpi-1.4.4.tar
cd openm*
./configure --prefix=/home/kpachar1/meep/local
make
make install
cd ..


wget http://www.hdfgroup.org/ftp/HDF5/releases/hdf5-1.6/hdf5-1.6.10/src/hdf5-1.6.10.tar.gz
cd hdf5-1.6.10
./configure --prefix=/home/kpachar1/meep/local
make clean
make
make install
cd ..



wget http://ab-initio.mit.edu/h5utils/h5utils-1.12.1.tar.gz
gunzip h5utils-1.12.1.tar.gz
tar -xf h5utils-1.12.1.tar
cd h5utils-1.12.1
export LDFLAGS=-L/home/kpachar1/meep/local/lib
export CPPFLAGS=-I/home/kpachar1/meep/local/include
./configure --prefix=/home/kpachar1/meep/local
make clean
make
make install
cd ..


wget http://ab-initio.mit.edu/meep/meep-1.1.1.tar.gz
gunzip meep-1.1.1.tar.gz
tar -xf meep-1.1.1.tar
cd meep-1.1.1
./configure --prefix=/home/kpachar1/meep/local --with-libctl=/home/kpachar1/meep/local/share/libctl --with-mpi
make clean
make
make install
meep-mpi
cd ..