My workspace

One of my friend ask me to develop a course for students in subject "Machine Learning". Course should be very simple to familiar students with machine learning. Main purpose of this course is to explorer the machine learning world to the students and playing over this topics with own their hands. Machine learning is very much matured and a lot of tools and frameworks is available to wet your hands in this topics, however most of the articles or tutorials you could found in the internet will start installing cluster or have to write a bunch of code (even, in site mahout, they are using maven) to start learning. Even more not all students are familiar with hadoop or do not have very powerful notebook to install and run all the components to get test of machine learning. For these reasons i have got the following approach: Standalone Hadoop Standalone Mahout  And a few CSV data files to learn how to works with Predictions Assume you already have java installed in your work s...

Recently we start getting a few complains from our client related to connection on DataBase from IBM WAS. First action we have taken to take a look on log which we got from the client and discovered these following errors on application logs: Error 404: Database connection problem: IO Error: Got minus one from a read call DSRA0010E: SQL State = 08006, Error Code = 17,002 java.sql.SQLException: The back-end resource is currently unavailable. Stuck connections have been detected. With a quick search on google i have found  PMR 34250 004 000 on IBM support sites, which is also effect IBM WAS 8.* version. As soon as we are using third party web portal engine ( BackBase ) it was travois to figure out the problem, so we decompiled some code to make sure that all the data source connection closing well. After some research i have asked data base statistics and data source configurations from support team of the production. And i was  surprised with the data base statistics th...

In your entire software development, sooner or later you will got a few project with very low budget, where you can't use commercial software because the budget is low and in the long run company also want some profit completing the project. From the begging of the year i have done a few pre-sale for such projects and decided to write down a list of all open source alternatives against commercial product. One thing i have to clear that, i have no religious view over open sources software or vica verse. There a plenty of reasons to use most of the commercial product but most of all time we have to cut our coat according to our cloths. 1) BPM : Most of all vendor like Oracle and IBM have their finest product in BPM, such as Oracle BPM Server, IBM Business process manager. Also you can find a few very good open source product such as JBPM from Jboss and Bonitasoft. But their are another very good open source BPM engine you can try, it's Activity . Spring based (state machine) li...

A few years ago (2011) in Java One Conference in Moscow, i participated with presentation about CI. During this time a lot of changes has been made with this fields. By the years many tools, plugins and frameworks has been released to help devOps to solve problems with CI. Now CI is one of the vital part of the development life cycle. With the aggressive use of cloud infrastructure and horizontal scaling of every application, now most of all application deployed in a lot of server (virtuals and dedicated). Moreover, most of the systems are heterogeneous and always need extra care (scripts) to successfully deploy the entire system. Most of the time development environment is very different from the production environment. Here is the common workflow from the development stage to production DEV environment -> Test Environment -> UAT environment -> Production environment. Every environments has their own characteristics, configurations. For example, most of the developers use ...

Last few months we are developing a portal for 3rd largest bank in Europe. Unique visitor of the bank grows more than 1 million visitor in a day. The main non functional requirements of the project is the high availability of the portal and giving high through output. One of the main feature of the portal is to giving user to customize their pages with widgets and provide different services for targeted auditory. After a long discussion and analysis, bank decided to use java based engine to build up the portal and we have got the following stack: 1) Java 1.7_47 2) IBM WEBSphere 8.5 as Application server 3) Nginx as web server 4) Alteon as load balancer 5) Oracle 11gR2 as DataBase 6) SOLR for content search Main challenge for us to supported legacy browser such as IE8, opera 12 e.t.c and one portal for all device (desktop, smart phone and tablet pc). Java based portal engine generated a lot of java script which didn't give us very good performance. For these above reasons we...

Offtopic: My first book "High performance in-memory computing with Apache Ignite" has been released and available at http://leanpub.com/ignite . This post is my review of the Packt Publishing book Cassandra High Availability by Robbie Strickland. As the main title suggest. The book has almost 186 pages covering 9 chapters and must read for Cassandra users. Chapter 1: Cassandra's approach to High Availability The initial chapter of Cassandra High Availability cover some architectural design such as Monolithic Architecture, Master slave Architecture and the Cassandra's approach to achieve high availability. Most of all modern software system requires a non functional requirements such as High availability. In this chapter author briefly describe why RDBMS is the single point of failure and is not suitable for horizontal scaling, also the drawback of the Master Slave architecture. In the next few section Author describe the Cassandra's architecture and it's...

This post is my review of the Packt Publishing book Cassandra Design patterns by Sanjay Sharma. As the main title suggest, it's all about pattern and anti pattern of using Cassandra. The book has almost 74 pages covering 6 chapters. Preface: What this book covers and Who this book is for The preface of the book starts with the ideas behind this book. The main idea behind this book is for Cassandra audience to understand where and how to use Cassandra correctly and effectively.The Preface also provides brief summaries of each of the six chapters in the book and convention that follows in this books. Under the section "What you need for this book", author specified that, readers don't need any special version of Cassandra, however Cassandra 2.0 or above version will be proffered. The "Who this book is for" section of the Preface specify the audience of the book, it may be architect, or developer starting with Cassandra. Chapter 1: An Overview of Architect...