King of Pop - MJ

Michael Jackson died yesterday. He was considered the King of Pop and a megastar of music industry. Despite all accusations, he is one of those people who really made a difference. RIP MJ.

Building Axis2

This is a bug (I think) which I came across a couple of times, while building Axis2. To overcome this you have to follow 2 simple instructions ;). For the completeness of this blog post, I will direct you through he complete build process.

1. First checkout the source.

svn co http://svn.apache.org/repos/asf/webservices/axis2/trunk/java

2. Build the project from the source. Do not skip the tests, when you do a fresh build.

mvn clean install

NOTE:

Now is the tricky part. If you are not getting build errors, then no problems at all :). If you start getting build errors related to plugins, then do the following to overcome it.

1. First build the axis2-aar-maven-plugin.

2. Then build the axis2-mar-maven-plugin.

3. Afterwards, build axis2. This should pretty much overcome the build error :).

Jython extension for Apache Axis2

In a earlier post I mentioned that my proposal for GSoC 2009 was accepted. There I didn't give much details on what my project is about. Here is a description of my project.

If you have tried out WSO2 WSF/Jython, you will know that it is based on code-first approach. Web services, is a technology to deliver the architectural style defined in SOA. Although there seems to be a general confusion about the relationship between SOA and Web services, it is important to know that Web services are an implementation methodology that adopts standard protocols to execute SOA. There are two widely used techniques in Web service development, ie.

1. Code First
2. Contract First

With the contract-first approach, the contract for the Web service is determined first and then the supporting tools are used to generate the implementation code. In contrast, in the code-first approach, first the implementation code is created and then the Web service development framework is used to produce the contract for the Web service.

In simpler terms; in WSF/Jython what I am doing is asking you to write the web service and the client. Then based on the service, a WSDL is generated and exposed as a Web service. Afterwards jython client can be used to invoke the service (ie. code-first).

When it comes to contract-first it is vice versa of the above scenario. First we will have to take the provided WSDL in to consideration. Then based on this WSDL, the code should be generated. Following are the advantages of using contract first approach.

• Loose coupling between applications
• Interoperability between multiple services
• Abstraction hides underlying implementation details
• Collaboration and agreement between all parties

Prof: V. K. Samaranayake Commemoration

The Students' Union of UCSC commemorated late Prof. V.K. Samaranayake by donating equipment to Army Hospital at Narahenpita on 18.06.2009. Prof. Samaranayake was considered the "Father of Information Technology" in Sri Lanka.

Writing a Web Server in C

Though the above heading may give you a headache when thinking "how to do it?", in practical sense it is pretty simple. I'm not talking about a fully functioning Web Server with wide array of functionalities, but a simple Web Server that will cater basic requirements of a Web Server. Through web surfing I found out some interesting web links which helped me to write my simple Web Server.

The way in which I did it was,

1. First, got hold of a chat server (I used a one which I have written already).
2. Then implemented the logic for handling http.

Following links helped me a lot in understanding the domain knowledge. If you'd like to have a look at the code feel free to drop a comment, I will be more than happy to share it with you :) .

• Beej's Guide to Network Programming Using Internet Sockets
• Client-Server Background
• nweb: a tiny, safe Web server
  

MPI vs Pthread

I did a performance comparison between my MPI & pthread codes for Matrix multiplication. Matrices used were 1000*1000 and MPI code was run on UCSC's swelanka cluster (using 4 CPUs). While the MPI code took only 2.6 seconds to multiply two 1000*1000 matrices, the pthread code took more that 45 seconds(on avg).

Checking Hardware configuration of your Linux Distribution

Following are some useful commands to check your h/w configuration in linux.

1.Linux Flavor

$ cat /etc/issue

2.CPU

$ cat /proc/cpuinfo

3.RAM

$ cat /proc/meminfo

4.Hard Disk

$ df -h