CQRS

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Axon Framework: Event Sourcing with 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

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Introduction to CQRS(Working, Uses, Benefits)

Reading Time: 2 minutes Overview The Command and Query Responsibility Segregation (CQRS) pattern separates read and write operations for a data store. Reads and writes may take entirely different paths through the application and may be applied to different data stores. CQRS relies on asynchronous replication to progressively use writes to the read view so that changes to the application state instigated by the writer are eventually observed by the reader. How CQRS Works Consider, for Continue Reading

A Brief Introduction to Axon Framework

Reading Time: 3 minutes Need for Axon Framework Axon Framework is designed to support developers in applying the CQRS/DDD architectural pattern and Event Sourcing. It helps developers build easily scalable and maintainable applications by providing implementations of some basic building blocks, such as Aggregates, repositories, and event buses  Axon Framework, founded by Allard Buijze also working for Trifork, is an open source product with version 3 planned for Q1 2016. CQRS Example Using Continue Reading

How Kafka Relates to Axon Framework?

Reading Time: 3 minutes Axon and Kafka are used for different purposes, Axon is used for Event-Driven Architecture and provides the application-level support for domain modeling and Event Sourcing, as well as the routing of Commands and Queries, while Kafka serves as an Event Streaming system. The basic fundamental of Axon is to implement CQRS and Event Sourcing-based architecture.  With the help of this, we can design & develop Continue Reading

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Introduction to CQRS and Event Sourcing

Reading Time: 3 minutes CQRS CQRS (Command Query REsponsibility Segregation) is a very simple pattern and not new at all. CQRS is based on the Command Query Separation (CQS) principle which was suggested by Bertrand Meyer. CQS suggest that we divide the operation on domain object into two distinct categories: Queries and Commands. The Command and Query Responsibility Segregation(CQRS) it’s an architectural Pattern Where the main focus is to Continue Reading

Axon Part 3: Exploring The AxonIQ Initializr

Reading Time: 3 minutes Prerequisites: If you are reading this blog I assume you are already familiar with the Axon Framework basics. If not, please visit “Axon Part 1: An Introduction to Axon Framework” to get started  with Axon. Introduction: Initializers are the tools that help us start off with our project right away by automating some of the tasks which we need to go through every time we Continue Reading

Axon Part 2 : Structure, Spring Boot Integration and Server Setup

Reading Time: 4 minutes This is Part 2 of an ongoing series of blogs explaining Axon Framework. This blog is going to take you a step ahead and help you know more about the application directory structure to be followed. Also we’ll understand the spring boot integration for Axon. Additionally, this blog will have a quick Axon Server Setup Guide. Prerequisites: Go through the Axon Part 1 – An Continue Reading

Axon Part 1: An Introduction to 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

Lagom Read side and Write side

Reading Time: 3 minutes Lagom is a framework that is used for building reactive microservices. It provides support for building read side and write side views of the data so that querying a microservice becomes easier. In this blog, I’ll discuss about how having a read side view is beneficial and also important in microservices. Before reading this blog I’ll recommend you to have some knowledge about Event Sourcing Continue Reading

Understanding data persistence in Lagom

Reading Time: 4 minutes When we create any microservice, or in general any service, one of the biggest task is to manage data persistence. Lagom supports various databases for doing this task. By default, Lagom uses Cassandra to persist data.