Tuning Hadoop & Cassandra : Beware of vNodes, Splits and Pages

When running Hadoop jobs against Cassandra, you will want to be careful about a few parameters. Specifically, pay special attention to vNodes, Splits and Page Sizes. vNodes were introduced in Cassandra 1.2. vNodes allow a host to have multiple portions of the token range.  This allows for more evenly distributed data, which means nodes can share the burden of a ...

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How JPA 2.1 has become the new EJB 2.0

java-interview-questions-answers

Beauty lies in the eye of the beholder. So does “ease”: Learn more about SQL Result Set Mappings and handle your native query results with ease: http://t.co/WH4BTlClIP #JPA #Java #JavaEE — Thorben Janssen (@thjanssen123) April 15, 2015 Thorben writes very good and useful articles about JPA, and he’s recently started an excellent series about JPA 2.1’s new features. Among which: ...

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Geb Gems: Running Geb Spock tests with Maven

Geb is framework which makes it easy to create functional tests for your application. Since you can use Groovy, Spock and the elegance of the JQuery selector, you can setup solid functional test very easy. In this blogpost we will make a simple test which will test a functional part of the JDriven website. We will start our test with configuring the ...

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Spark: Generating CSV files to import into Neo4j

About a year ago Ian pointed me at a Chicago Crime data set which seemed like a good fit for Neo4j and after much procrastination I’ve finally got around to importing it. The data set covers crimes committed from 2001 until now. It contains around 4 million crimes and meta data around those crimes such as the location, type of ...

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Design Patterns in the 21st Century: The Abstract Factory Pattern

This is part two of my talk, Design Patterns in the 21st Century. This pattern is used everywhere in Java code, especially in more “enterprisey” code bases. It involves an interface and an implementation. The interface looks something like this: public interface Bakery { Pastry bakePastry(Topping topping); Cake bakeCake(); } And the implementation: public class DanishBakery implements Bakery { @Override ...

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