As you all know, restarting HTTPD service is not idempotence in nature and also consumes more resources. So, here is away to rectify this challenge in Ansible playbook using handlers.

What are handlers in Ansible?

Handlers are just like normal tasks in an Ansible playbook but they run only when if the task contains a “notify” directive. It also indicates that it changed something.

By default, handlers run after all the tasks in a particular play have been completed. This approach is efficient, because the handler only runs once, regardless of how many tasks notify it. …


Pre-requisite:-

You should have pre-configured controller and managed node of ansible.

So, let’s get started…

Step 1:- First, we have to configure yum for installing the docker. The code for the same is as follows:-

- hosts: all
tasks:
- yum_repository:
description: "Docker yum repo"
name: "Docker Repo"
baseurl: "
https://download.docker.com/linux/centos/7/x86_64/stsble/"
gpgcheck: no

Step 2:- Now, download the docker software using the following code:-

- package: 
name: "docker-ce-18.06.3.ce-3.el7.x86_64"
state: present

Step 3:- Before starting the docker service, we need to install a python package named docker-py in the target node as ansible is dependent on python. By installing docker-py, the system will…


What is Hadoop?

Hadoop is an open-source framework that allows to store and process of big data in a distributed storage environment across the cluster of computers. It provides massive storage for any kind of data, enormous processing power, and the ability to handle virtually limitless concurrent tasks or jobs.


Do you know? The New York Stock Exchange generates about one terabyte of new trade data per day. 500+terabytes of new data get ingested into the databases of social media site Facebook, every day. A single Jet engine can generate 10+terabytes of data in 30 minutes of flight time. So, are you thinking that how these data are stored and managed by these companies?

So, before finding the solution let us discuss about the problem i.e., Big Data.

What is Big Data?

Big Data is also data but with a huge size. Big Data is a term used to describe a collection of data…


What is LVM?

LVM is a tool for logical volume management which includes allocating disks, striping, mirroring and resizing logical volumes. With LVM, a hard drive or set of hard drives is allocated to one or more physical volumes. LVM physical volumes can be placed on other block devices which might span two or more disks.

The physical volumes are combined into logical volumes, with the exception of the /boot partition. The /boot partition cannot be on a logical volume group because the boot loader cannot read it. If the root (/) partition is on a logical volume, create a separate /boot partition…


A hard disk can be divided into several partitions. There may be several reasons for creating the partitions. Some of them are as follows:-

  • Multiple operating systems on the same disk.
  • Different file systems on different partitions.
  • More efficient disk space management.
  • Different security settings on different partitions.
  • Easier backup procedure.

So let’s get started…

Step 1:- First, we need to attach a external storage device to our VM or Bare-metal.


Step 1:- First, we have to install the docker software. For that we have to configure the yum repolist.

For configuring the yum repo, use the following commands:-

cd /etc/yum.repo.d/
gedit docker.repo


The Docker adoption is still growing exponentially as more and more companies have started using it in production. It is important to use an orchestration platform to scale and manage your containers.

Imagine a situation where you have been using Docker for a little while, and have deployed on a few different servers. Your application starts getting massive traffic, and you need to scale up fast; how will you go from 2 servers to 50 servers that you may require? How would you monitor all these containers and make sure they are restarted if they die? …


Before creating the setup, we should understand some of the important terms.

Routing Table:- A routing table is a set of rules, stored in a router or a network host that lists the routes to particular network destinations, and in some cases, metrics (distances) associated with those routes. The routing table contains information about the topology of the network.

  • Network ID:- The network ID or destination corresponding to the route.
  • Subnet Mask:- The mask that is used to match a destination IP address to the network ID.
  • Next Hop:- The IP address to which the packet is forwarded.
  • Outgoing Interface…

Have you ever looked up at night and wondered about the mysteries of space? Or marveled at the expansiveness of our galaxy? You can easily explore all this and more at the NASA Image and Video Library. For NASA, providing the public with such easy access to the wonders of space has been a journey all its own.

NASA began providing online access to photos, video, and audio in the early 2000’s, when media capture began to shift from analog and film to digital. …

Ananya Sharma

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