2024

Dockerizing my blog

I have never worked with Docker. I have never created a Dockerfile, containerized an app, run it as a service, or interacted with it. I did take some courses on O’Reilly, but without active practice, I forgot what I had learned in those courses. Finally, I decided to build something with Docker, and I did that by dockerizing my blog.

5 min read
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2023

Spark - Needle in a haystack story

In this short blog post, I will share an example of how executor logs helped us in narrowing down a malformed record that was causing our code to throw java.lang.ArithmeticException long overflow exception

3 min read
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2021

Localstack & Terraform

In this blog post, we are going to see an example of how we can use the localstack framework for testing terraform deployments.

6 min read
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2019

Spark Patterns - FlatMapGroups

In this blog post, I am going to explain you with an example on how we can use the FlatMapGroups api for implementing complex logic against grouped datasets.

5 min read
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2018

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2017

Working with schema in SparkSQL

In this blog post, we will see how to apply schema to SparkSQL DataFrames. We will also see, how to use Scala’s implicits for converting DataFrame into strongly typed entities.

5 min read

SparkSQL Getting Started

In this blog post, I am going to explain you the steps required for configuring Spark in your machine. I will also present simple SparkSQL program which runs SQL query against sample csv file.

9 min read

Spark Recipes

If we ignore the complexities of running spark applications then getting up-to speed with spark programming api is relatively straight forward. However like any other programming api, spark too contains some elements that aren’t that obvious to figure out. In this post, I will share some not so obvious things about spark programming api.

4 min read

Using Symbolic Links to Manage Libraries

This post is quick tutorial on how you can easily manage & switch between different versions of programming libraries that you have configured in your machine with the help of symbolic links.

1 min read

Mixin in Scala

In this blog post, we will look into how Scala provides support for mixins via traits. Mixin allow classes to provide functionalities to other classes without making the other classes inherit from them.

3 min read

Unhandled & Dead Messages in Akka

In this blog post, we are going to look into two special cases of message delivery & its handling by the akka framework. First case involves sending invalid message & second case involves sending messages to dead actors.

4 min read

Scala Topics - Actor Based Programming

In this blog post, I am going to use Akka’s Actor framework for implementing code for scoring Bowling game. Before getting into the code, I will provide quick introduction to Actors & components involved in actor based programming.

10 min read

Scala Topics - Covariance & Contravariance

In this blog post, I am going to explain you the difference between covariance & contra-variance. If you are not familiar with these terms then let me tell you that its related to the way type parameters are handled(more on this) when defining generic types or methods.

4 min read
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2016

Advent Of Code 2016

I recently came across this site called Advent Of Code which lists set of problems in increasing order of complexity. If you are like me, trying to learn new programming language(in my case it’s Scala), then solving handful of such problems will greatly expedite your learning process.

9 min read

Scala Topics - Case Classes

In this blog post, I am going to cover Scala’s Case class functionality. Scala being functional programming language, introduces new programming constructs like Case classes, traits & other features to support & enhance functional programming experience.

7 min read

Postgres and Json - Part2

In this blog post, we are going to explore some of the json related operators & functions specific to filtering & processing of json based data.

6 min read

Postgres and Json - Part1

In this blog post, we are going to look into the various json related functions available in postgres database specific to json creation.

8 min read

Postgres - BackUp & Restore

In this blog post, I am going to share with you all the commands required for taking database back-up & restoring database from those back-up files.

2 min read

Why Blog?

I have recently joined the local Toastmasters club in my office. The idea behind the Toastmasters club is to promote & improve public speaking by encouraging participants to give speeches either prepared lengthy speech lasting about 5 to 7 minutes or do an impromptu speech for about 2 minutes on any random topic. I can say with confidence that I have experienced drastic change in myself. I no longer shiver with fear of giving speech by facing large group of audience. Now this blog post is not going to be about the merits of Toastmasters instead I am going to use this post as placeholder for my next speech which is going to be on public writing aka Blogging.

5 min read
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2015

MEANT Stack Part2 - Node & Mongoose SetUp

Table of Contents

In the previous post, we went through the steps of installing necessary software’s & modules required for building our application. In this post, we are going to concentrate on our application backend i.e. setting up node as as web server & mongoose related codebase for performing CRUD activities in the underlying mongo database.

7 min read

MEANT Stack - Part1

Table of Contents

In this multi-part blog series, I will walk you through on how to build a small web application using  Nodejs, MongoDb, TypeScript & AngularJs. We will be building a small web application for creating and registering teams. A team will have team members and a unique team name. The application will have two screens. First one used for creating a new team and the other one used for listing all the registered teams. In this post, we will concentrate on installing & setting up of required software’s. Let’s get started.

5 min read

Going Functional - Symbol Graph in F#

In the previous post, we have seen the implementation of undirected graph data structure in F#. In this post, we will make use of the Graph data structure to implement the Symbol Graph data structure. You can read more about Symbol Graph data structure here. Given below is the java based implementation of Symbol Graph data structure. The implementation if taken from Algorithms 4th Edition by Robert Sedgewick and Kevin Wayne.

6 min read

Going Functional - Merge & Quick Sort in F#

Continuing our functional journey, in this post I will first present the Java based implementation of merge sort followed by F# based implementation. Finally we will repeat the same steps for QuickSort algorithm. Java based implementation of the sorting algorithms is taken from Algorithms 4th Edition by Robert Sedgewick and Kevin Wayne.

5 min read

Going Functional - Stack Implementation in F#

In this blog post, I will port linked list based Stack ADT code in C# to F#. Given below is the C# implementation. It’s inspired from the Java based implementation provided in the Algorithms 4th Edition book by Robert Sedgewick and Kevin Wayne. The Stack ADT class is called LLStack because .Net framework itself contains Stack data structure.

5 min read

Is Screen Saver running or not?

Although its rare but at times while building desktop based applications, we might come across situation wherein we are asked to handle “Screen Saver” operation i.e. perform some logic based on whether the “Screen Saver” is on of off. I found the following code snippet on internet almost two years back. I would like to thank the original author of the code. It’s been long time and its not possible for me to search for the original author of the code.

1 min read

Async Web Api Performance

In one of my recent WPF project, we made extensive use of async-await pattern. Async-await pattern greatly simplified the call-back and continuation based code required for keeping the UI responsive. In WPF, the pattern for implementing async-await is to invoke the IO/CPU intensive code in a background thread and attach the continuation logic on the main UI thread. In WPF, since we have a dedicated UI thread that controls all of the UI elements, using async-await is really helpful in keeping the UI responsive without having to write complicated call-back based code.

4 min read

Podcast for developers

Podcasts are a great way of utilizing your time while you are on the move i.e. driving car or riding in a bus/train. If you are unlucky like me, who has to spend couple of hours each day travelling between office & home and vice versa, then listening to podcasts while you are stuck in traffic can be of great help. Not only are you learning something new but it also helps you in keeping calm and makes the journey appear comparatively shorter.

2 min read

Dependency Injection in PowerShell

In this blog post, I will explain how we can invoke dependency injection based managed code from PowerShell. Invoking regular managed code from PowerShell is quiet straight forward. Say for example, you are asked to create an instance of HttpClient class and call the GetStringAsync method on it, then it can be done with just following few lines of code.

2 min read
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2012

Laptop Inauguration

Today I received my new laptop which is an Intel Core i5-2450M @ 2.50GHz 4 GB RAM machine . The other laptop(office provided) which I have used for past two years for programming is an Intel Core2 Duo T6570 @ 2.10GHz machine. Reason why I am talking about the laptops that I own is because of my interest in writing multi-threaded/parallel code using the new TPL API provided in the .Net 4.0 framework. I have spent significant amount of time in past one year writing code using the Parallel API of .Net framework. But given the fact that the hardware that I was using for running those applications wasn’t that great, I was never much satisfied with the overall improvement in performance.

4 min read
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