Kotlin

In this series of simulating and troubleshooting performance problems in Kotlin, let’s discuss how to make threads go into BLOCKED state. A thread will enter into a BLOCKED state when it couldn’t acquire a lock on an object because another thread already holds the lock on the same object and doesn’t release it. Kotlin blocked thread Program Here is a ...

In this series of simulating and troubleshooting performance problems in Kotlin articles, let’s discuss how to simulate CPU consumption to spike up to 100% on a host (or container). CPU consumption will spike up whenever a thread goes on an infinite loop. Kotlin CPU Spike Program Here is a sample kotlin program, which generates the cpu spike. package com.buggyapp class ...

 This is second in a series of posts exploring service to service call patterns in some of the application runtimes on Google Cloud. The first in the series explored service to service call patterns in GKE.  This post will expand on it by adding in a Service Mesh, specifically Anthos Service Mesh, and explore how the service to service patterns ...

This is a series of posts that will explore service to service call patterns in some of the application runtimes in Google Cloud. This specific post will explore GKE without using a service mesh and the next post will explore GKE with Anthos Service Mesh. Set Up The set-up is simple, two applications – caller and producer are hosted on ...

In a previous post I had gone over how a “Try” type can be created in Kotlin from scratch to handle exceptions in a functional way. There is no need however to create such a type in Kotlin, a type called “Result” already handles the behavior of “Try” and this post will go over how it works. I will be ...

In this post we will learn how we can use Kotlin extension functions to provide a simple and elegant type conversion mechanism. Maybe you have used Apache Sling before. In this case, you are probably familiar with Slings usage of adapters. We will implement a very similar approach in Kotlin. Creating an extension function With Kotlins extension functions we can ...

Functional programming languages like Scala often have a type called “Try” to hold the result of a computation if successful or to capture an exception on failure.  This is an incredibly useful type, allowing a caller to pointedly control how to handle an exceptional scenario. In this post I will try and create such a type from scratch. As an example, ...

Dependency injection is a common technique in today’s software design. With dependency injection we pass dependencies to a component instead of creating it inside the component. This way we can separate construction and use of dependencies. In this post we will look at Koin, a lightweight Kotlin dependency injection library. Koin describes itself as a DSL, a light container and ...

Jackson Kotlin module library is a pleasure to use. It greatly simplifies gnarly code, specifically one’s involvingTypeReference.  Consider a sample json which looks like this: 1 2 3 4 5 {     "a" : ["b", "c"],     "b" : ["a", "c"],     "c" : ["a", "b"] } This content can be represented as a “Map<List<String>>” type in Java.  So now, if I were ...