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There are many blogs saying CKAD is a tough certification exam and it’s very hard to crack it. I agree that it’s hard, but it can be cracked effectively by a planned execution and strategy.

I cracked the Certified Kubernetes Application Developer(CKAD) Exam within 30 days from the day initially i started preparing for the exam.

Below are some of the strategies which i followed and executed it to achieve this prestigious CKAD certification:

Find best course to learn.

The best course for preparing for CKAD is Mumshad Mannambeth’s course on Udemy.com

The great part in this course is that it helps in learning by doing. It has interactive labs sessions on each topic, practice labs and mock exams (not exact). …


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Working on vim is always challenging and it become more important to have complete control on vim commands when working on remote machine.

Most Useful Features of vim

The following sections explain the following categories of vi commands.

  • Moving around in a file
  • Inserting text
  • Changing and substituting text
  • Undoing changes to text
  • Deleting text
  • Copy-Cut-Paste Text

Note : Most vi commands are case sensitive. The same command typed in lowercase and uppercase characters might have different effects.

1. Moving around in file

Move the cursor using combinations of the up, down, right, and left arrow keys.

a. Moving One Word

  • Press w (“word”) to move the cursor to the right one word at a time. …


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Spring-boot app is all about annotation based development and fast code deployments within embedded servers and all.

To take it further, containerising a spring-boot is an added technical skill, which is in high demand currently.

So lets learn to containerise a spring-boot application. Here are the steps covered in this article:

  1. Install Docker
  2. Install Virtual box
  3. Install Kubernetes on MacOS (Minikube)
  4. Install network gateways (Istio-ingress)
  5. Create docker image
  6. Create kubernetes yaml file
  7. Deploy on kubernetes cluster (minikube)
  8. Enable Port forwarding
  9. Monitor application deployment (Kiali and Lens)

Prerequisite :
a. I assume you should know Spring-boot app creation and project setup before moving further. If you are not familiar with this, go through complete setup process
in this article.


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Starting mongo as a standalone single instance is straight forward. But on production environments, mongo db is always running in clustered format.

So how to replicate the same clustered format mongo db on your local machine or on staging instances or for testing purposes becomes critical.

The steps include:

  1. Download the mongo binary (Mongo installation)
  2. Create data directories for different nodes of the cluster
  3. Start mongo nodes pointing to different ports (as we are running all node on one machine)
  4. Initiate replica set
  5. Ready to use

1. Download the mongo binary

Download any mongo repository from mongo official website.

Extract the binary in your local directory. Say we extracted the binary in /Users/myUser/Documents/mongodb. …


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We often require to run a cron job on our staging or production environment.

This is how we can achieve this in linux:

1. Create a bash script

2. Schedule execution of the above script with crontab

Create a bash script

This is what the actual piece of work to be done.

Simply open any of your favourite editor and create the script. For a simple example add the lines as follows:

#!/bin/sh

a=`ps -ef | awk ‘/my-java-program.jar/{print $2}’`
b=`echo $a | head -1`
echo “killing job “

kill -9 $b

echo “starting job “
l=`date +”%d-%m-%y-%T”`
nohup java -jar /home/user/my-java-program.jar > /usr/logs/$l.log 2>&1 &

and save the file as myscript.sh in /home/user/ directory. …


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Most of the times we may require to change the configurations of the application which are running as service in ubuntu or linux or mac os.

And finding out the straight forward solution took a lot of time for me and finally came to know that only two commands is that what is required.

This story will definitely save your precious couple of hours.

There are following steps to for this:

  1. Stop the service
  2. Finding out the service configuration file.
  3. Way to edit the configuration file.
  4. Start the service

Stop the service

The service for which configuration needs to be changed should be stopped first. Lets assume, we need to change the tomcat service, the service can be stopped…


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Creating a Spring-boot multi-module project in Intellij IDEA and maintaining such project can land lots of developers to great trouble.

This article is all about creating the spring multi-module project, maintain it, troubleshoot things and all configuration related matter.

So, here is what we are going to cover in this:

  1. What is sprint multi-module
  2. Why multi-module
  3. Create a spring-boot multi-module project
  4. Add one more module!!!

What is a multi-module project

A multi-module project is one in which there could be child-parent relationships between different components of your project. …


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The sole purpose of writing this article is to solve the issue of getting Read time out Exception while fetching all edges of a SuperNode using Janusgraph.

For finding the solution to this problem, there are many links available online on github, Google forum and Stackoverflow.

This article specifies the following things additionaly:

  1. What is a graph database (Janusgraph here) and how to use it.
  2. A simple Janusgraph Java client for OLAP queries.
  3. How to enable Janusgraph to support super-node i.e a node which have millions of incoming and/or outgoing edges.
  1. What is a graph database (Janusgraph) and how to use it.

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Up until recently, Bash was the default shell used in macOS. If you’re still using an account under Bash, here’s a quick how-to manipulate your .bash_profile file.

Create .bash_profile

To create the bash_profile, proceed with the following steps:

  1. Open the terminal.
  2. Move the home directory using the following command:
    cd ~/
  3. Use the touch command to create the bash_profile as follows:
    touch .bash_profile

Edit .bash_profile

  1. To edit the .bash_profile inside the terminal, either use vim or vi as follows:
    vi ~/.bash_profile
  2. If the bash_profile is large, then it becomes difficult to edit in the terminal itself. So we can use the TextEdit to edit bash_profile in such cases. …


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Spark | Scala | Functional Programming

I have been working with Java for 7 years now and lately started working with Apache Spark for some real world the big data and data science projects.

And when starting with Apache Spark, and based on the implementation and API support provided by Spark, there comes a very big question:

Which language should i choose?

Which is the most preferred language when working with Spark?

And believe me you are the right place to find the answer for all above questions. Stay tuned!!

Moving further, Apache Spark provides three options to choose from:

  1. Java
  2. Scala
  3. Python

So this article will be moving on with all above three options, with pros and cons of each and will suggest what best suites to a particular developer with a particular background. …

About

KARAN VERMA

Software Architect

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