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Showing posts from April, 2015

An impatient start with Mahout - Machine learning

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

Configuring stuck connection in IBM WAS 8.5.5 Connection pool

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 that all connect

Open sources alternatives for low budget projects

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

Continuous Integration (CI), A review

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