Alternatives for Agile and Lean Roadmapping: Part 2, Rolling Wave Planning Inside One Quarter

In Part 1, I wrote about thinking in feature sets and how to quickly create a feature set of—with any luck—smaller features. That’s because features don’t arrive at the same rate and they change in value, during a quarter. Because features change in value and because some feature sets need to deliver value on a more regular basis, the real roadmap looks ...

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Lucene’s near-real-time segment index replication

[TL;DR: Apache Lucene 6.0 quietly introduced a powerful new feature called near-real-time (NRT) segment replication, for efficiently and reliably replicating indices from one server to another, and taking advantage of ever faster and cheaper local area networking technologies. Neither of the popular search servers (Elasticsearch, Solr) are using it yet, but it should bring a big increase in indexing and ...

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MQTT Security: Securing Mosquitto Server

This post describes how to implement MQTT security. In more details, we will describe how to securing Mosquitto MQTT server. As you may already know MQTT is one of the most important protocols widely used in Internet of things and in Industrial Internet of things. MQTT is a lightweight messaging oriented protocol where MQTT client exchanges messages through an MQTT server ...

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Streaming large JSON file with Jackson – RxJava FAQ

In the previous article, we learned how to parse excessively large XML files and turn them into RxJava streams. This time let’s look at a large JSON file. We will base our examples on tiny colors.json containing almost 150 records of such format: { "aliceblue": [240, 248, 255, 1], "antiquewhite": [250, 235, 215, 1], "aqua": [0, 255, 255, 1], "aquamarine": [127, 255, 212, 1], ...

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The Apache Ignite Native persistence, a brief overview

java-interview-questions-answers

In-memory approaches can achieve blazing speed by putting the working set of the data into the system memory. When all data is kept in memory, the need to deal with issues arising from the use of traditional spinning disks disappears. This means, for instance, there is no need to maintain additional cache copies of data and manage synchronization between them. ...

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Spring Webflux – Kotlin DSL – a walkthrough of the implementation

In a previous blog post I had described how Spring Webflux, the reactive programming support in Spring Web Framework, uses a Kotlin based DSL to enable users to describe routes in a very intuitive way. Here I wanted to explore a little of the underlying implementation. A sample DSL describing a set of endpoints looks like this: package sample.routes import org.springframework.context.annotation.Bean ...

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What is JavaServer Faces (JSF) – (Part 2)

Facelets Declaration Language In part 1 I introduced the basic idea behind JavaServer Pages (JSF). In this article, I would like to introduce the Facelets declaration language. HTML tags The first tags we meet are the HTML tags that represent HTML elements. These are really just syntactic sugar over HTML tags such as input, radio button etc. but provide some ...

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GC Explained: Heap

Generational Garbage Collectors JVM heap is divided into two different Generations. One is called Young and the second one is the Old (sometimes referred to as Tenured). The Young Generation is further separated into two main logical sections: Eden and Survivor spaces. There are also Virtual spaces for both Young and the Old Generations which are used by Garbage Collectors ...

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