Prasanna Kumar

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Java 8 lambdas

Scheduled for release in 2013 , Java 8 will include language support for lambda functions. Although the specification is still in flux, lam...

An example showing the new syntactic sugar for constructor reference and lambda expressions introduced in Java 8. Inspired by http://www.techempower.com/blog/2013/03/26/everything-about-java-8

import java.util.List;<p>import java.util.ArrayList;<p>import java.util.Arrays;<p>import java.util.function.Supplier;<p>import …

Java: adding state to interfaces in Java 8 (pre-release)

Java 8 introduces the concept of default methods to interfaces and this post looks at the cost of adding state to them.<p><i>This information pertains to</i> …

Code Smells: Deeply Nested Code

Or: I wants all your data, give it to me… my precious….Continuing the series of code smells and what do about them, in this post, I examine some …

IntelliJ IDEA

Spring Boot + RESTful + JUnit + Mockito + Hamcrest + EclEmma

In this tutorial I will show you how to setup from scratch a RESTful Spring Boot project and the unit test implementation using the following tech …

Episode 06: Intro to Architecture and Systems Design Interviews

YouTube

The System Design Primer

<i>English ∙ 日本語 ∙ 简体中文 | Brazilian Portuguese ∙ Italian ∙ Korean ∙ Persian ∙ Polish ∙ Russian ∙ Traditional Chinese ∙ Turkish | Add …

How Uber Manages a Million Writes Per Second Using Mesos and Cassandra Across Multiple Datacenters

If you are Uber and you need to store the location data that is sent out every 30 seconds by both driver and rider apps, what do you do? That’s a lot …

Scalability

YouTube Architecture

<b>Update 2:</b> YouTube Reaches One Billion Views Per Day. <i>That’s at least 11,574 views per second, 694,444 views per minute, and 41,666,667 views per</b> …

Databases

Distributed systems for fun and profit

Introduction<p>I wanted a text that would bring together the ideas behind many of the more recent distributed systems - systems such as Amazon's Dynamo, …

Software Development

Distributed Runtimes: at-least-once is here

Introducing at-least-once processing with Apache kafka!<p>If you are charging money for processing logs, you simply cannot afford to lose a single data …

E-mail

Stream computing is one of the hot topic at the moment. It’s not just hype but actually a more generic abstraction that unifies the classical …

INTRODUCTION TO MICROSERVICES

Traditional development methodologies encourage the ‘monolithic’ approach to application development. Building a single application that does …

JUnit Cheat Sheet

This post continues our series of the most useful and beautiful cheat sheets from which software engineers can learn the most frequently used …

Java & JVM Conquer the World | Page 9 of 12

Profiling Tools<p><b>Measure</b> before you jump<p>The worst thing you can do when trying to fix a performance problem is to make assumptions. You’re guaranteed …

Service Discovery: Zookeeper vs etcd vs Consul

The more services we have, the bigger the chance for a conflict to occur if we are using predefined ports. After all, there can be no two services …

Transactions in Microservices

A microservice does a business unit of work. Transaction boundaries in most cases will span a business unit of work; hence, the transactions are …

10 Tips to Push Your Git Skills to the Next Level — SitePoint

Recently we published a couple of tutorials to get you familiar with Git basics and using Git in a team environment. The commands that we discussed …

Reducing merge headaches: git meets diff3

git has an option to display merge conflicts in diff3 format (by default it only displays the two files to be merged). You can enable it like so:<p>$ …

Quick Tip: Leveraging the Power of Git Stash

Imagine that you're working on a feature in a Git-controlled software project. You're right in the middle of making some changes when you get a …

A Hacker's Guide to Git

<i>A Hacker’s Guide to Git</i> is now available as an e-book. You can purchase it on Leanpub.• Introduction<br>• Repositories<br>• Tree …

Software Development

Marketplace Trial

One of the most useful features of any version control system is the ability to "undo" your mistakes. In Git, "undo" can mean many slightly different …

DevOps

Jump Start Git

<i>The following is a short extract from our book, Jump Start Git, available for free to SitePoint Premium members. Print copies are sold in stores</i> …

The Hardest Part About Microservices: Your Data

Continuing on with my series about microservices implementations (see “Why Microservices Should Be Event Driven”, “Three things to make your …

Microservices

We're all distributed systems devs now: a crash course in distributed programming

Going forward, every developer who works in server-side development will be expected to understand the fundamental concepts that drive the design of distributed systems. It's a matter of when, not if.<p>​In this talk we'll dive into concepts such as the CAP theorem, eventual consistency, …

Data-Driven Web Service Testing with Assertive Validation

Introduction<p>Many organisations today, especially those in business domains where customers have mobile devices, develop their IT landscape around Web …

The Fault in Our JARs: Why We Stopped Building Fat JARs

HubSpot’s backend services are almost all written in Java. We have over 1,000 microservices constantly being built and deployed. When it comes time …

Microservices

Understanding Consensus and Paxos in Distributed Systems

Computers can sometimes be unexpectedly tricky. Having them accomplish seemingly rudimentary tasks can be a lot more complicated than we would …

Smart Unit Tests – Test to Code Binding, Test Case Management

<i>[Editor’s note: “Smart Unit Tests” has been renamed to “IntelliTest” with effect from Visual Studio 2015 Release Candidate (RC).]</i><p>In an earlier post …

8 Principles of Better Unit Testing -- Enterprise Systems

Writing good, robust unit tests is not hard -- it just takes a little practice. These pointers will help you write better unit tests.<p>By Dror …