Knoldus Blogs

Axon Framework: Event Sourcing with MongoDB

August 3, 2022August 5, 2022application design, Axon, CQRS, Database, event, Event Sourcing, Java, Messages, MongoDB, NoSql, Spring, Web ApplicationAxon, Axon Framework, Domain Driven Design, Event Processing, event sourcing, MongoDB

Reading Time: 4 minutes If you want to build Microservices, You may prefer Axon, a Java-based framework. It provides utility to implement CQRS (Command Query Responsibility Segregation), Event Sourcing, and DDD (Domain Driven Design) architectural patterns while developing a software application. Axon facilitates the implementation of Command Handling, Event Routing, Event Sourcing, Snapshotting, and many more building blocks. It has very friendly APIs to use these implementations and build Continue Reading

Introduction to RabbitMQ

December 29, 2021December 29, 2021Messages, MessagesAPI, Other, Tech BlogsRabbitMQ

Reading Time: 3 minutes The world is a stage where all of us are artists. Constant learning is the foundation of success. So here we are going to learn about an open-source message broker technology which is RabbitMQ. Overview RabbitMQ is the open-source message broker software that uses AMQP to transfer data. i.e, RabbitMQ accepts messages from producers and delivers them to consumers. So, RabbitMQ is like a middleman Continue Reading

Axon Part 1: An Introduction to Axon Framework

July 12, 2021July 16, 2021application design, Architecture, CQRS, Messages, MessagesAPI, Microservices, Tech BlogsAxon, Axon Framework

Reading Time: 3 minutes This is the first part of an ongoing series of blogs explaining Axon Framework. This blog will help you get started with axon and get a basic understanding of the same. Prerequisites Understanding Axon requires a basic knowledge of a few Axon concepts. Those are: Microservices Command Query Responsibility Segregation(CQRS) Commands, Events and Queries Domain Driven Design(DDD) Event Sourcing SAGA Design Pattern Introduction Problem: The Continue Reading

Creating Data Pipeline with Spark streaming, Kafka and Cassandra

August 24, 2020October 22, 2020Apache Kafka, Apache Spark, Big Data and Fast Data, Cassandra, MessagesAPI, Spark, Streaming, Studio-ScalaApache Kafka, Apache Spark, Cassandra, data analysis, DataStream API

Reading Time: 3 minutes Hi Folks!! In this blog, we are going to learn how we can integrate Spark Structured Streaming with Kafka and Cassandra to build a simple data pipeline. Spark Structured Streaming is a component of Apache Spark framework that enables scalable, high throughput, fault tolerant processing of data streams.Apache Kafka is a scalable, high performance, low latency platform that allows reading and writing streams of data Continue Reading

Kafka Timestamp Extractor

December 18, 2019December 18, 2019Apache Kafka, Big Data and Fast Data, cluster, Event Sourcing, Lagom, Messages, MessagesAPI, Microservices, Streaming, Streaming Solutions, Studio-Scala, Tech Blogskafka, Kafka Streams, mess, messge delivery

Reading Time: 3 minutes Hi folks, I hope you all’re doing well, so if you land up here you probably looking for Timestamp Extractor for kafka streams, so whats the buzz is all about? So in this blog we are going to look what it is and would explore it as well, so buckle up. The Timestamp Extractor As per docs, A timestamp extractor extracts a timestamp from an Continue Reading

Monitor a Kafka stream application with Graphite-Grafana using JMX metrics

March 5, 2019Apache Kafka, Architecture, Big Data and Fast Data, cluster, DCOS, Docker, Java, Messages, Microservices, Non-Blocking, Reactive Programming, Studio-DevOps, Studio-Scala, Web

Reading Time: 5 minutes A few days back, we got the requirement that we need to monitor a Kafka stream application using JMX metrics. We looked for the solution and reached to the conclusion which we will discuss in this blog. I will try to explain each and every component of the solution along with the setup and the integration part of the whole system. Proposed solution: Service (application) exposes Continue Reading

Use Case for Message-driven Reactive Systems

January 9, 2019January 9, 2019Architecture, Lagom, Messages, MessagesAPI, Microservices, Non-Blocking, Reactive Application, Reactive Programming, Studio-Scala

Reading Time: 5 minutes The Case for Message-driven Reactive Systems.

CAP Theorem for the distributed systems

December 16, 2018Architecture, Big Data and Fast Data, Business Insights, cluster, couchbase, Database, Messages, Microservices, ML, AI and Data Engineering, Reactive Programming, Studio-Scala

Reading Time: 4 minutes A few days back I completed the certification for the 1st course of the Lightbend Reactive Architecture Advanced i.e. Building Scalable Systems. I found this course very helpful and informative to get the idea of Reactive architecture. So if you have not started yet, please go there and lets become reactive. There are few foundational courses as well to build the foundation of reactive architecture. Continue Reading

One-way & two-way streaming in a Lagom application

November 27, 2017July 24, 2018Akka, Big Data and Fast Data, Functional Programming, github, Java, Messages, Reactive Application, Streaming, Studio-Scala, Web Services

Reading Time: 2 minutes Now a days streaming word is a buzz word and you should have heard many types of streaming till now i.e. kafka streaming, spark streaming etc etc. But in this blog we will see a new type of streaming i.e Lagom-streaming. Lagom-streaming internally uses Akka streams, with the help of which we will see one way & two way streaming. But before going forward, it Continue Reading

A Java Lagom service which only consumes from Kafka topic (Subscriber only service)

September 4, 2017September 10, 2018Akka, Apache Kafka, Architecture, Big Data and Fast Data, Functional Programming, github, Java, MessagesAPI, Microservices, Studio-Scala

Reading Time: 2 minutes Subscriber only service means an application which only consumes, does not produce. We have generally seen the applications which both produces and consumes data from a Kafka topic but sometimes we need to write an application which only consumes data i.e. consumes data from a 3rd party service. So in this blog I am going to explain how to write a Lagom service which only Continue Reading

AMPS: Empowering real time message driven applications.

July 16, 2017September 10, 2018Messages, MessagesAPI, Studio-Scala

Reading Time: 3 minutes Greetings!! In this blog, we will talk about AMPS, a pub-sub engine which delivers messages in real time with a subject of interest. AMPS is mainly used by Financial Institutions as enterprise message bus. We will also demonstrate how we can use AMPS with to publish and subscribe messages with an example. So, let’s start with introducing AMPS. What is AMPS? Advanced Message Processing System Continue Reading

Messages and internationalization in Play 2.4.x

September 14, 2015September 14, 2015Messages, MessagesAPI, Play 2.4.X, Play Framework, Studio-Scalai18n, Internationalization, Messages, play, Play Application, Play framework, scala

Reading Time: 3 minutes In this blog we would discuss about Messages and internationalization in Play Framework which would drive us through the implementation and testing of the Play MessagesAPI. Messages and internationalization Play supports Internationalization (i18n) out of the box by leveraging the underlying internationalization support. With Play you are able to customize the text that appears in a view based on the user’s Locale. Specifying languages supported Continue Reading