≡ Menu

Howto Setup Apache Zookeeper Cluster on Multiple Nodes in Linux

Apache ZookeeperIf you are running Apache zookeeper in your infrastructure, you should set it up to run in a cluster mode. Zookeeper cluster is called as ensemble.

For a cluster to be always up and running, majority of the nodes in the cluster should be up. So, it is always recommended to run zookeeper cluster in odd number of servers. For example, cluster with 3 nodes, or cluster with 5 nodes, etc.

In this tutorial, we’ll setup zookeeper cluster with 3 node setup on the following servers: node1, node2, and node3.

How to Setup Git Repository and Credentials for Jenkins Jobs

Jenkins is an open source automation server, which will help you to automate the application deployment in your infrastructure.

From Jenkins, for deployment, you can connect to any kind of source code control system, and pull the source, build it, and deploy it automatically to one or more servers.

In this tutorial, we’ll explain how you can create a new Jenkins Job, and connect it to a Git repository to pull the source code for building.

C Program Example to Generate Cluster of Dots

In this tutorial, we would write an example C program that will create a file which will serve as producer of testing data.

In another words, we will create an application in C, and your task is to input the number of clusters, number of dots for each of those clusters, and then to generate random numbers that are in those clusters.

The output file generated by this program can then be used by other programs as sample data.

A while back, I tried to write a simple weather prediction program, but I had no real life data to apply my algorithm and try out my application. Sometimes, it is very hard to generate the data that are required to test your application. That was the motivation for me to write some simple program like this, which will give you some idea on writing your own program to generate test data.

What is virtualization?

In simple terms, virtualization is a simulated platform or environment on top of a host node, which is quite abstract for an user.

These simulated virtual environment can be an operating systems, or some development environment, etc.

This gives us the ability to efficiently use the hardware resources of the host node.

How to Fix Curl TLS SSL Protocol Issue from CLI and PHP Code

Q: On one of our server, the webserver is not setup to support SSLv2 or SSLv3. Both are disabled on the server side. It supports only TLSv1. How can I get curl to work from both command line, and from inside my PHP code?

A: In most case, curl will automatically pick the correct protocol and connect to it. But, you can also specify a specific protocol to use for curl command. In this example, you have to instruct CURL to use TLSv1, as explained in this tutorial.

7 Steps to Migrate Google Apps Gmail to Microsoft Office 365 Email

If your organization is using Google Apps gmail, and if you are considering to migrate it to Microsoft Office 365, this tutorial will explain everything that you need to know to complete the migration.

The following are the high-level steps that are covered in this tutorial:

  1. Sign-up for Office 365 and create admin account
  2. Verify Your Domain in Office 365
  3. Create User Mailboxes and assign Office 365 License
  4. Create Migration Endpoints with Gmail IMAP
  5. Create List of Users for Migration Batch
  6. Create Migration Batch to Migrate Mailboxes
  7. Update DNS – Repoint MX Records to Microsoft


How to Deploy Node.js Script on Linux Using Upstart and Monit

Node.js LogoNode.js is a server-side scripting and Javascript framework.

This runs on top of Chrome V8 Engine.

What makes it different is that the application developed using node can be seen as a server responding to your request. When scripting using node.js, we are creating a http server which keeps on responding to your request.

In other words, when you are running a nodejs application you are running an instance of a http server.

Its quite different from the scenario where you install a separate web server like Apache or Nginx with appropriate language compiler packages and then deploying your code under the DocumentRoot of that webserver.

How to Install and Configure Oracle SQL Developer Client

If you are working on Oracle database either as developer or DBA, you need a good front-end to manage your database.

In the old days, one of the popular option was Toad.

But, now, there is even a better and robust option; SQL Developer.

SQL Developer is an oracle product. It is free.

It is a very good IDE for developers who write lot of PL/SQL code.

It is also an excellent DBA tool to manage your database. You can also uset it to run reports, create data model, and also to migrate database.