Author Archives: Ajitesh Kumar
Java – How to Migrate from JRockit to HotSpot JVM
This article represents information on migration from JRockit to HotSpot JVM. Recently, the migration guide from JRockit JVM to HotSpot JVM has been published. The information about the same can be found on this page. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. The detailed information could be found on this page. Following are top 5 areas where changes need to be made for migrating from JRockit JVM to HotSpot JVM. Tuning garbage collection. One could also access HotSpot GC tuning guide on following page. Java runtime options Java compilation optimization Logging: There are parameters related to verbose …
Top 5 Pages listing Big Data Conferences in 2016
This article represents top 5 pages listing global big data conferences coming up in 2016. Please feel free to comment/suggest if I missed to mention any other important pages. Also, sorry for the typos. Following are the top 5 pages: Global Big Data Conference KDNuggets List of Meetings/Conferences on Analytics, Big Data, Data Mining, Data Science Important Big Data events coming up in 2016 Big Data conference directory listing big data conferences happening around the world. O’Reilly List of conferences of on various topics including Big Data
Top 7 Reasons to use Dockers for Testing Your Application
This article represents some of the key reasons on why one should consider using dockers for testing their applications. Some of the points in this blog is taken from the video, Stop being Lazy and Test your Software presented by Laura Frank, currently working in CodeShip. Do check out videos for gathering greater details. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: What are key testing bottlenecks? How could Dockers alleviate Testing Bottlenecks Key Testing Bottlenecks Slower performing tests or slower running tests due to bad coding or not sufficient infrastructure Traditional testing …
Dockers – How to Get Started with Cloudera
This article represents information and code/scripts which could be used to get started with Cloudera using Dockers. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: Docker machine configuration Cloudera & Dockers Test the Cloudera installation Scripts to install & run Cloudera Docker Machine Configuration To run the cloudera in docker container, one would require to do following configuration to the Docker machine. Open Oracle VM Virtualbox Manager. Stop the default machine. Then, change the settings as shown below. Change the processor (core) setting to 2 Change the memory …
Docker – Create Javascript Development Environment
This article represents Dockerfile code sample which could be used to create Javascript Development environment. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: Javascript Development environment Dockerfile representing JS Development Environment One script used for Images/Containers Javascript Development Environment Following tools are installed to make Javascript development environment. NodeJS runtime Typescript compiler Grunt-cli Bower JSHint for code quality check Jasmine for unit tests Dockerfile representing JS Development Environment Following dockerfile (nodejs_base.df) could be used to create NodeJS base image and represents NodeJS runtime. # Use centos6 base image …
TypeScript Hello World Program – Code Sample
This article represents code samples on writing Hello World program with TypeScript. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: Setting up Typescript Development environment TypeScript Hello World Program Setting up Typescript Development environment Use the instructions on following page to setup the TypeScript development environment. Docker – How to setup Typescript Development Environment TypeScript Hello World Program interface Person { firstname: string; lastname: string; } function hello(person: Person) { return “Hello, ” + person.firstname + ” ” + person.lastname; } var calvin = {firstname: “Calvin”, lastname: “Hobbes”}; …
Docker – How to Create Javascript Runtime using NodeJS
This article represents information on how to install Javascript runtime in order to compile/interpret JS file for the purpose of testing. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: Install NodeJS Runtime with Docker Container Script to Create NodeJS Container Test JS script execution Many a times, we come across the need to write the Javascript file and run it using a Runtime without the need to test the Javascript code using an HTML page. We could achieve this objective using NodeJS runtime. We shall use Docker to …
Docker – How to Setup Typescript Development Environment
This article represents code samples on how to get setup with Typescript development environment with Dockers. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: Build NodeJS & NPM image Build Typescript image Create Typescript container One script to create images & Typescript container Build NodeJS & NPM Image Following code can be used to create NodeJS/NPM image. # Use base image of centos6 FROM centos:centos6 # Enable Extra Packages for Enterprise Linux (EPEL) for CentOS RUN yum install -y epel-release # Install Node.js and npm RUN yum install …
One Datastore per MicroService?
This article represents details on whether to use single datastore per microservice. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. From what I researched, the preferred architecture for microservices is polyglot persistence pattern. (http://martinfowler.com/bliki/PolyglotPersistence.html ). You could further read about this on following pages: http://martinfowler.com/articles/microservices.html#DecentralizedDataManagement http://microservices.io/patterns/data/database-per-service.html As per the best practices, each micro-service should have one database private to it. There are different ways to achieve the above objective. Some of them are listed below: Same database system for different services. In this following could be done: Different set of tables specific to microservice in the same database …
Hadoop Map-Reduce Explained with an Example
This article represents key steps of Hadoop Map-Reduce Jobs using a word count example. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key steps of how Hadoop MapReduce works in a word count problem: Input is fed to a program, say a RecordReader, that reads data line-by-line or record-by-record. Mapping process starts which includes following steps: Combining: Combines the data (word) with its count such as 1 Partitioning: Creates one partition for each word occurence Shuffling: Move words to right partition Sorting: Sort the partition by word Last step is Reducing which comes up with …
Big Data – How Data is Retrieved and Written from/to HDFS?
This blog represents my notes on how data is read and written from/to HDFS. Please feel free to suggest if it is done otherwise. Following are steps using which clients retrieve data from HDFS: Clients ask Namenode for a file/data block Name-node returns data node information (ID) where the file/data blocks are located Client retrieves data directly from the data node. Following are steps in which data is written to HDFS: Clients ask Name-node that they want to write one or more data blocks pertaining to a file. Name-node returns data nodes information to which these data blocks needs to be written Clients write each data block to the data nodes suggested. The …
Hadoop Map-Reduce Described With Example
I came across a great page describing Hadoop map-reduce and HDFS architecture. The page presents some of the following details: HDFS responsibilities and execution flows Key characteristics of Map-Reduce lifecycle A sample example related with web crawler and Hadoop Map-reduce setup
5 Reasons Why Every Developer Must Adopt Dockers
This blog represents some of the key reasons why every developer must consider adopting for development. 1. Setup clean Dev environment within no time. Many a time, while developing, we end up changing configuration. Installing new libraries etc. With this act, the Dev environment deviates to a new state which may be different from expected QA and Production environment. With Dockers, one could rather update the image and create new containers in case new libraries need to be installed. 2. Setup Dev environment within minutes. As a matter of fact, developers could actually recreate the Dev environment every morning before starting his work. This ensures that he maintains the state …
Dockers – Top 5 Use Cases for Dockers Adoption
This blog represents top 5 use cases why IT enterprises (product & software-service vendors) should consider adopting Dockers in their SDLC. 1. Quicker Developer Onboarding into Projects: We all are aware of development environment setup related issues when taking about developers on boarding. In my recent experience, I almost spent a week to get manually setup for a recently started project comprising of just 3-4 members. I had to refer to couple of documents which was last updated few weeks back and thus was not up to date. This led to productivity loss. In my earlier experience, I saw the usage of VMs images for developer onboarding. This worked very …
ReactJS – Step-by-Step Tutorial on Quiz Development
I just finished up writing a simplistic/trivial framework using ReactJS using which one could quickly create online quizzes. The code for this could be found on github on following page named as ReactJS-Quiz. I would like to take this opportunity to share AngularJS-Quiz that I wrote sometime back. I must say that I found writing quiz framework using ReactJS more fulfilling as it got aligned to my OOP oriented thinking and I was not required to envisage templates etc as in case of AngularJS. That said, both frameworks are cool and have their own pluses and minuses. Please feel free to suggest if I missed on mentioning one or more …
ReactJS – What is this.props.items.map Property?
This article represents concepts around usage of “map” method to traverse and display list of similar objects representing a component in ReactJS. The title represents “this.props.items.map”, although it could be anything such as “this.props.profiles.map” like in examples below where profiles or items represent an array. It could be used to create a list, table etc. Please feel free to comment/suggest if I missed to mention one or more important points. Also, sorry for the typos. Following are the key points described later in this article: Map is NOT a feature of ReactJS Code Sample – Usage of “map” as in this.props.profiles.map Map is NOT a feature of ReactJS After looking …
I found it very helpful. However the differences are not too understandable for me