Home » Author Archives: Biju Kunjummen (page 2)

Author Archives: Biju Kunjummen

Scatter-Gather using Spring Reactor Core

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I have a good working experience in using the Netflix Rx-Java libraries and have previously blogged about using Rx-Java and Java 8 CompletableFuture for a scatter-gather kind of problems. Here I want to explore applying the same pattern using the Spring Reactor Core library. tldr – If you are familiar with Netflix Rx-Java, you already know Spring Reactor Core, the API’s map beautifully ...

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First steps to Spring Boot Cassandra

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If you want to start using Cassandra NoSQL database with Spring Boot, the best resource is likely the Cassandra samples available here and the Spring data Cassandra documentation. Here I will take a little more roundabout way, by actually installing Cassandra locally and running a basic test against it and I aim to develop this sample into a more comprehensive example with the next ...

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Spring Boot with Scala

spring-interview-questions-answers

A while back I had tried out a small Spring Boot  based sample with Scala as the language and found that the combination works out quite nicely – no big surprises there actually as Scala programs ultimately run in the JVM. I have now updated the sample with the latest version of Spring Boot and some of the supporting libraries. ...

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Spring Cloud Ribbon – Making a secured call

spring-interview-questions-answers

Something simple, but I struggled with this recently – I had to make a Netflix Ribbon based client call to a secured remote service. It turns out there are two ways to do this using Netflix Ribbon, I will demonstrate this through Spring Cloud’s excellent support for Ribbon library. In two previous blog posts I have touched on Spring Cloud ...

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JWT – Generating and validating a token – Samples

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JWT provides a very interesting way to represent claims between applications that can be verified and trusted. My objective here is to show a small sample to generate and validate a token using the excellent Nimbus JOSE + JWT library. Overview One of the best places to get an intro is here. In brief, to borrow from the material from ...

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Spring Cloud Rest Client with Netflix Ribbon – Basics

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In an earlier blog post I had covered the different options for a REST client in the Spring Cloud world. All the options wrap around a Netflix OSS based component called Ribbon which handles the aspects related to loadbalancing the calls across different instances hosting a service, handling failovers, timeouts etc. Here I will cover a few ways to customize ...

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Spring Cloud support for Hystrix

spring-interview-questions-answers

Spring Cloud project provides comprehensive support for Netflix OSS Hystrix library. I have previously written about how to use the raw Hystrix library to wrap remote calls. Here I will be going over how Hystrix can be used with Spring Cloud Basics There is actually nothing much to it, the concepts just carry over with certain Spring boot specific enhancements. ...

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Gentle Introduction to Hystrix – Wrapup

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This is a follow up to two other posts – Motivation for why something like Hystrix is needed in a distributed systems and a basic intro to Hystrix. This will be a wrap of my Hystrix journey with details of various properties that can be tweaked to change the behavior of Hystrix and will touch on a few advanced concepts ...

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Gentle Introduction to Hystrix – Hello World

java-interview-questions-answers

In a previous blog post I had covered the motivation for needing a library like Netflix Hystrix. Here I will jump into some of the very basic ways to start using Hystrix and follow it up with more complex use cases. Hello World A simple Hello World example of a “Hystrix Command” is the following: import com.netflix.hystrix.HystrixCommand; import com.netflix.hystrix.HystrixCommandGroupKey; import ...

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