Introduction to Zookeeper

What is Zookeeper ? Apache ZooKeeper is an opensource project which can be used to develop a highly scalable, robust and reliable centralized service to implement coordination in a distributed environment. It enables application developers to concentrate on the core business logic of their applications and let the ZooKeeper service to get the coordination part … Read more

Zookeeper tutorial

In this ZooKeeper tutorial we will learn how to download, install and move our first steps with Zookeeper distributed coordination system. ZooKeeper is implemented in Java and requires Java 6 or later versions to run. While Oracle’s version of Java is recommended, OpenJDK should also work fine for the correct functioning of ZooKeeper Oracle’s version … Read more

Clustering Zookeeper

In this tutorial we have learnt how to set up a ZooKeeper server instance in standalone mode: Zookeeper quickstart. A standalone instance is a potential single point of failure. If the ZooKeeper server fails, the whole application that was using the instance for its distributed coordination will fail and stop functioning. Hence, running ZooKeeper in … Read more

Quick introduction to Vagrant

Vagrant is a program that enables you to create portable and reproducible development environments easily supporting many hosts and guests operating systems and various features such as synced folders, forwarded ports and support for famous provisioners such as Chef, Puppet or Ansible. If you have been using tools like Virtual Box you may think of … Read more

Vagrant tip #4 Configuring a multimachine static environment

In this tip we will see how to configure a Multimachine Fedora ennvironment with two Fedora machines bound on a static IP address. Vagrant and Multi-VM environments allow developers to model complex multi-server setups on a single development machine The IP addresses we will reserve to the Fedora Machines are the following ones: … Read more

Ansible HelloWorld

Ansible is an automation engine that automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT needs. Ansible works by connecting to your nodes and pushing out small programs, called “Ansible Modules” to them. These programs are written to be resource models of the desired state of the system. Ansible then executes … Read more

Hot replacement of your JBoss – WildFly classes using Fakereplace

In this tutorial we will learn how to replace your application’s Java classes running in WildFly / JBoss EAP without re-deployment using a tool named Fakereplace. Replacing your applications while developing them is a need for every developer. Some commerical solutions like JRebel have enhanced this process by making possible it possible for Java developers … Read more