Saturday, December 20, 2014

Packt Ebook Bonanza Campaign

I came across this promotional offer from packt publications for this festive season:

Following the success of last year’s festive offer, Packt Publishing will be celebrating the Holiday season with an even bigger $5 offer.
From Thursday 18th December, every eBook and video will be available on the publisher’s website for just $5. Customers are invited to purchase as many as they like before the offer ends on Tuesday January 6th, making it the perfect opportunity to try something new or to take your skills to the next
level as 2015 begins.
With all $5 products available in a range of formats and DRM-free, customers will find great value content delivered exactly how they want it across Packt’s website this Xmas and New Year.

 To avail this offer, visit:
Or see twitter hashtag #packt5dollar

Sunday, December 7, 2014

D3.js Tips and Tricks: Using Plunker for development and hosting

D3.js Tips and Tricks: Using Plunker for development and hosting your D3.js visualizations 

I've just been finishing up with a D3 visualization pet project and found this free and amazing hosting service to showcase your product to the world. Hope this helps others too.

Friday, November 21, 2014

Custom Java Metrics in Eclipse

Recently, a relative inquired if I could provide a tool to calculate custom metrics for java code, so I began search and found an old, but open source plugin for eclipse that does just exactly that- calculate metrics without doing any fluffy stuff.
I took its source code and provided it on github.

I had to do minor changes to make it working quickly, which was to use only the metrics table prospective and hide the views not in use.

Here, the metrics need to be provided with 2 essential things:
  1. The name of metric in the plugin.xml file (which is read by the plugin in the list of metrics to calculate)
  2. Name of the calculator file, which contains the logic used in calculating a specific metric value

The required custom metrics were outlined in a paper that discussed about quality of object oriented design and was academic in nature, so the nature of metrics created is quite simple.

For instance, the metric 'Inheritance Ratio' took the form of following tag in plugin.xml

    name="Inheritance Ratio"

and also mapped its logic via the calculator tag:
    name="Inheritance Ratio"

Next, there is need of simply creating this calculator file and overriding the calculate method. Another thing is to create constants like INHR (in this example) by which the metric and its calculator may communicate during runtime.

So, by piggybacking on this application, I was easily able to provide the metrics tool without worrying anything about the UI and source code management. I plan to finish this quickly and then improve it as per suggestions, which are always welcome!

Tuesday, November 11, 2014

Book Review: High Performance Python

High Performance Python by Micha Gorelick and Ian Ozsvald

To a causal user of python, this book might not seem interesting or handful, but if one is working on an application that desires the maximum effeciency out of computer, no matter how the code is structured, there is a need to go deeper and find out how the code actually works and this starts from knowing how to best write the code that ensures minimum of cpu cycles and ram.
The book starts with an overview of the various data structures and libraries that python offers as well as detailing the internal structure of various computer architecture. It then moves on to profiling and detecting bottlenecks both via memory and cpu cycles. In sucessive chapters, this is further explained as different forms of data structures are discussed. Similarly the performance gains provided by third party libraries like NumPy are discussed in detail, which is a learning experience. The chapter on compilers is also informative - the benefits of compilation depending upon which compiler is chosen. Important concepts like concurrency and multiprocessing are discussed in detail for the I/O and CPU bound problems.
Overall this is a book that you would like to keep in handy as a reference while designing a performant architecture or improving a python based application's response time. For me, this was an eye opener and a reckoner for improving the designg and effeciency of a python application and many concepts were beyond me at times, but I hope to learn more about python internals and this is a book that I will visit in future - to confirm my findings and keep on learning deeper concepts.
Disclaimer: I have been provided a free copy of this book by OReilly under their Blogger review program.

Wednesday, October 29, 2014

Using Hybris for e-commerce

Recently, I had a chance to work on Hybris, which is a private company (now acquired by SAP) offering an application framework with the same name, which is a customizable platform for handling e-commerce B2B and B2C needs. While I was initially skeptical of the framework in the sense that it is not apparently clear how to create an online store like Magento or Spree, but is much more than a CMS that creates a shopping front-end for the user.
Technically, hybris is a framework built on top of spring that runs on a customized tomcat or SpringSource DM Server and uses maven for build automation. While this architecture is carefully thought out, the problem lies with its openness- the community is quite limited and as learners, we are restricted to the hybris wiki and forums. Given the evolving nature of the application (different versions come frequent and fast), opening it up would make a lot of sense. As SAP recently acquired Hybris, it may provide integration with its tools and databases in future as well as provide forums and community support like other mainstream software.

Coming back to uniqueness in this framework, here are a few notable observations:
Open-Close model: While the software is not open source, the way of creating application on top of framework comes with least surprises and there is a lot of flexibility.
User oriented: Cockpits are specialized interfaces that power users/admins of the software can use to quickly access the information present in their application.
Thought out: Like a matured product, entire gamut of e-commerce application is present and one can not only provide the http based web solution but also plugin with an existing application.
Scalable: As jvm based approach is followed, it is quite scalable - though it requires an upfront resource allocation during development, it sure pays back to ensure the scalability of the website.
Performance: The customization comes at a cost of computing resources, as well as slow/complex process workflows. The overall performance of the application if compared against other ecommerce solutions is worse.
XML based: The configuration is mainly in xml and parts like the UI is built on custom framework, which is pretty restrictive. While these might not be the issues, but they stuck out like a sore thumb to me, which brings us to another conclusion discussed in the next point.
Old standard Architecture: Application development seems archaic on this framework as the choice of the technologies used as well as provided seems to be a decade old - and regardless of the things mentioned on the website, integration with popular technologies is quite hard.

As I continue my exploration into this framework while working on real world projects, the things gained so far would help me to compare this against both open-source and corporate alternatives and enable me to contrast the differences more accurately against each of them.